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1
Fu, Xiaoling, Qi Zhang, Chao Wang, and Jiyun Tang. "Torque Coordination Control of Hybrid Electric Vehicles Based on Hybrid Dynamical System Theory." Electronics 8, no. 6 (June 23, 2019): 712. http://dx.doi.org/10.3390/electronics8060712.
Повний текст джерелаАнотація:
In order to reduce the vibration caused by mode switching of hybrid electric vehicles (HEVs) and achieve smooth mode switching, the hybrid input and output automation (HIOA) model of power control system of a parallel HEV is established based on the theory of hybrid dynamical system (HDS). Taking the switching from electric drive mode to hybrid drive mode for example, the torque coordination control is considered, and the performance is compared with the method without the torque coordination by using a rule-based control strategy. The simulation results in AVL Cruise show that, on the premise of ensuring the fuel economy and the emission, the mode switching process becomes smoother with smaller torque fluctuation and better driving comfort by considering the torque coordination.
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Mandel, J., E. Bergou, S. Gürol, S. Gratton, and I. Kasanický. "Hybrid Levenberg–Marquardt and weak-constraint ensemble Kalman smoother method." Nonlinear Processes in Geophysics 23, no. 2 (March 11, 2016): 59–73. http://dx.doi.org/10.5194/npg-23-59-2016.
Повний текст джерелаАнотація:
Abstract. The ensemble Kalman smoother (EnKS) is used as a linear least-squares solver in the Gauss–Newton method for the large nonlinear least-squares system in incremental 4DVAR. The ensemble approach is naturally parallel over the ensemble members and no tangent or adjoint operators are needed. Furthermore, adding a regularization term results in replacing the Gauss–Newton method, which may diverge, by the Levenberg–Marquardt method, which is known to be convergent. The regularization is implemented efficiently as an additional observation in the EnKS. The method is illustrated on the Lorenz 63 model and a two-level quasi-geostrophic model.
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Mandel, J., E. Bergou, S. Gürol, and S. Gratton. "Hybrid Levenberg–Marquardt and weak constraint ensemble Kalman smoother method." Nonlinear Processes in Geophysics Discussions 2, no. 3 (May 26, 2015): 865–902. http://dx.doi.org/10.5194/npgd-2-865-2015.
Повний текст джерелаАнотація:
Abstract. We propose to use the ensemble Kalman smoother (EnKS) as the linear least squares solver in the Gauss–Newton method for the large nonlinear least squares in incremental 4DVAR. The ensemble approach is naturally parallel over the ensemble members and no tangent or adjoint operators are needed. Further, adding a regularization term results in replacing the Gauss–Newton method, which may diverge, by the Levenberg–Marquardt method, which is known to be convergent. The regularization is implemented efficiently as an additional observation in the EnKS. The method is illustrated on the Lorenz 63 and the two-level quasi-geostrophic model problems.
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Vu, Trieu Minh, Reza Moezzi, Jindrich Cyrus, Jaroslav Hlava, and Michal Petru. "Parallel Hybrid Electric Vehicle Modelling and Model Predictive Control." Applied Sciences 11, no. 22 (November 12, 2021): 10668. http://dx.doi.org/10.3390/app112210668.
Повний текст джерелаАнотація:
This paper presents the modelling and calculations for a hybrid electric vehicle (HEV) in parallel configuration, including a main electrical driving motor (EM), an internal combustion engine (ICE), and a starter/generator motor. The modelling equations of the HEV include vehicle acceleration and jerk, so that simulations can investigate the vehicle drivability and comfortability with different control parameters. A model predictive control (MPC) scheme with softened constraints for this HEV is developed. The new MPC with softened constraints shows its superiority over the MPC with hard constraints as it provides a faster setpoint tracking and smoother clutch engagement. The conversion of some hard constraints into softened constraints can improve the MPC stability and robustness. The MPC with softened constraints can maintain the system stability, while the MPC with hard constraints becomes unstable if some input constraints lead to the violation of output constraints.
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Kehagias, Dimitris, Michael Grivas, and Grammati Pantziou. "Using a hybrid platform for cluster, NoW and GRID computing." Facta universitatis - series: Electronics and Energetics 18, no. 2 (2005): 205–18. http://dx.doi.org/10.2298/fuee0502205k.
Повний текст джерелаАнотація:
Clusters, Networks of Workstations (NoW) and Grids offer a new, highly available and cost-effective parallel computing paradigm. Their simplicity, versatility and unlimited power made them a rapidly adopted technology. It seems that they form the new way of computing. Although these platforms are based on the same principles, they differ significantly, needing special attention to their characteristics. Future computer scientists, programmers and analysts have to be well prepared, both about administrative and programming issues, in order to ensure faster and smoother transition. We present the architecture of a dynamic clustering system consisting of Beowulf class clusters and NoW, as well as our experience from constructing and using such a system, as an educational infrastructure for HPC.
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Yang, Y. Y., D. A. Linkens, and M. Mahfouf. "Genetic algorithms and hybrid neural network modelling for aluminium stress—strain prediction." Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 217, no. 1 (February 1, 2003): 7–21. http://dx.doi.org/10.1177/095965180321700103.
Повний текст джерелаАнотація:
This paper addresses the design of genetic algorithms in developing a hybrid neural network model for aluminium alloy flow stress prediction. The hybrid neural network model consists of a parallel grey-box model structure, with the resulting predictions combining the outputs from the constitutive equations and a neural network. Previous work shows that the hybrid neural network model can deliver better model performance than a neural network model or the constitutive equations. However, the level of performance improvement of the hybrid model depends on the quality of the constitutive model used. This motivates the search for a better constitutive model, with genetic algorithms being employed to optimize its parameters. The advantage of genetic algorithms is that they do not require any gradient information nor continuity assumption in searching for the best parameters. A number of genetic optimization schemes, with different coding schemes (such as binary coding and real-value chromosomes) and different genetic operators for selection, crossover and mutation, have been investigated. The real-value coded genetic algorithms converge much more rapidly and are more efficient since there is no need for chromosome encoding and decoding. Compared with previous work, the resulting hybrid model performance has been improved, mainly in the generalization capability and with a simpler neural network structure. Also, the model response surfaces are much smoother and more metallurgically convincing.
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Zhang, S., M. J. Harrison, A. T. Wittenberg, A. Rosati, J. L. Anderson, and V. Balaji. "Initialization of an ENSO Forecast System Using a Parallelized Ensemble Filter." Monthly Weather Review 133, no. 11 (November 1, 2005): 3176–201. http://dx.doi.org/10.1175/mwr3024.1.
Повний текст джерелаАнотація:
Abstract As a first step toward coupled ocean–atmosphere data assimilation, a parallelized ensemble filter is implemented in a new stochastic hybrid coupled model. The model consists of a global version of the GFDL Modular Ocean Model Version 4 (MOM4), coupled to a statistical atmosphere based on a regression of National Centers for Environmental Prediction (NCEP) reanalysis surface wind stress, heat, and water flux anomalies onto analyzed tropical Pacific SST anomalies from 1979 to 2002. The residual part of the NCEP fluxes not captured by the regression is then treated as stochastic forcing, with different ensemble members feeling the residual fluxes from different years. The model provides a convenient test bed for coupled data assimilation, as well as a prototype for representing uncertainties in the surface forcing. A parallel ensemble adjustment Kalman filter (EAKF) has been designed and implemented in the hybrid model, using a local least squares framework. Comparison experiments demonstrate that the massively parallel processing EAKF (MPPEAKF) produces assimilation results with essentially the same quality as a global sequential analysis. Observed subsurface temperature profiles from expendable bathythermographs (XBTs), Tropical Atmosphere Ocean (TAO) buoys, and Argo floats, along with analyzed SSTs from NCEP, are assimilated into the hybrid model over 1980–2002 using the MPPEAKF. The filtered ensemble of SSTs, ocean heat contents, and thermal structures converge well to the observations, in spite of the imposed stochastic forcings. Several facets of the EAKF algorithm used here have been designed to facilitate comparison to a traditional three-dimensional variational data assimilation (3DVAR) algorithm, for instance, the use of a univariate filter in which observations of temperature only directly impact temperature state variables. Despite these choices that may limit the power of the EAKF, the MPPEAKF solution appears to improve upon an earlier 3DVAR solution, producing a smoother, more physically reasonable analysis that better fits the observational data and produces, to some degree, a self-consistent estimate of analysis uncertainties. Hybrid model ENSO forecasts initialized from the MPPEAKF ensemble mean also appear to outperform those initialized from the 3DVAR analysis. This improvement stems from the EAKF’s utilization of anisotropic background error covariances that may vary in time.
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Yan, Shi Tong. "Hybrid Base and Parallel Hybrid Electric Vehicle Control Strategy." Applied Mechanics and Materials 599-601 (August 2014): 956–59. http://dx.doi.org/10.4028/www.scientific.net/amm.599-601.956.
Повний текст джерелаАнотація:
Automotive hybrid technology development and mechanical, electrical,engine,energy technology is closely related with the development of these areas of technology, the development of hybrid technology also will be extensive. How to optimize the control strategy is the key to achieve hybrid cars low fuel consumption, low emissions targets . In the automotive power and meet other basic technical performance,and cost requirements of the premise,characteristics and operating conditions for the car's various components , control strategies to achieve a reasonable distribution of energy in the motor between the engine and effective,so that the vehicle the highest system efficiency,access to the largest vehicle fuel economy,low emissions and smooth driving performance.
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Kalyankar-Narwade, Supriya, Ramesh Kumar Chidambaram, and Sanjay Patil. "Neural Network- and Fuzzy Control-Based Energy Optimization for the Switching in Parallel Hybrid Two-Wheeler." World Electric Vehicle Journal 12, no. 1 (March 1, 2021): 35. http://dx.doi.org/10.3390/wevj12010035.
Повний текст джерелаАнотація:
Optimization of a two-wheeler hybrid electric vehicle (HEV) is a typical challenge compared to that for four-wheeler HEVs. Some of the challenges which are particular to two-wheeler HEVs are throttle integration, smooth switching between power sources, add-on weight compensation, efficiency improvisation in traffic, and energy optimization. Two power sources need to be synchronized skillfully for optimum energy utilization. A prominent variant of HEV is that it easily converts conventional scooters into parallel hybrids by “Through-the-Road (TTR)” architecture. This paper focuses on three switching control strategies of HEVs based on the state of charge, fuzzy logic, and neural network. Further, to optimize energy usage, all these control strategies are compared. Energy management control for the TTR model is developed with vehicle parameters in the Simulink environment and simulated using the “World Harmonized Motorcycle Test Cycle” (WMTC) drive cycle. The multivariable input model is presented with a fuzzy rule-based hybrid switching control. A similar system is also modeled with a neural network-based decision control and the observations are tabulated for the fuel economy and energy management. Simulation results show that the neural network-based optimization results in minimal energy consumption among all three hybrid operations.
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Pang, Ming, Yikai Shi, Wendong Wang, and Shun Pang. "Optimal sizing and control of hybrid energy storage system for wind power using hybrid Parallel PSO-GA algorithm." Energy Exploration & Exploitation 37, no. 1 (June 25, 2018): 558–78. http://dx.doi.org/10.1177/0144598718784036.
Повний текст джерелаАнотація:
This paper proposes a frequency-based method for sizing the hybrid energy storage system in order to smoothen wind power fluctuations. The main goal of the proposed method is to find the power and energy capacities of the hybrid energy storage system that minimizes the total cost per day of all the systems. The energy management strategy used in this paper is designed as a two-level energy distribution scheme: the first level is responsible for setting the output power of hybrid energy storage system, the second level manages the power flow between the battery and supercapacitor. The hybrid parallel particle swarm optimization-genetic algorithm (PSO-GA) optimization algorithm is proposed to solve the control parameters of energy management strategy. In addition, the proposed method uses the piecewise fitting function to describe the lifetime of battery. Obtained results show that the hybrid energy storage system with the proposed energy management strategy is able to offer the best performances for the wind power system in terms of cost and lifetime.
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Yan, Yun Bing, Fu Wu Yan, and Chang Qing Du. "Research on Dynamic Torque Control Strategy for Parallel Hybrid Electric Vehicle." Advanced Materials Research 228-229 (April 2011): 951–56. http://dx.doi.org/10.4028/www.scientific.net/amr.228-229.951.
Повний текст джерелаАнотація:
It is necessary for Parallel Hybrid Electric Vehicle (PHEV) to distribute energy between engine and motor and to control state-switch during work. Aimed at keeping the total torque unchanging under state-switch, the dynamic torque control algorithm is put forward, which can be expressed as motor torque compensation for engine after torque pre-distribution, engine speed regulation and dynamic engine torque estimation. Taking Matlab as the platform, the vehicle control simulation model is built, based on which the fundamental control algorithm is verified by simulation testing. The results demonstrate that the dynamic control algorithm can effectively dampen torque fluctuations and ensures power transfer smoothly under various state-switches.
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Song, Meng Jun, Cheng Jun Ding, and Chang Juan Yu. "Workspace Analyzing for Hybrid Serial-Parallel Mechanism of a New Bionic Quadruped Robot." Applied Mechanics and Materials 713-715 (January 2015): 837–40. http://dx.doi.org/10.4028/www.scientific.net/amm.713-715.837.
Повний текст джерелаАнотація:
In this paper, a new bionic quadruped robot was proposed by us. The mechanism of robot we analyzed is as a hybrid series-parallel mechanism, so a new methods for constructing the kinematic model of the bionic quadruped robot very quickly and efficiently was introduced. we analyzed the workspace of the legged mechanism by using geometric composition method and numerical analysis method in the following section. Furthermore, the kinematic model of the parallel mechanism of the multi-motion mode bionic quadruped robot was constructed when the robot was in the stance phase, we also construct and solve the inverse kinematic model of the parallel mechanism of the robot, and the simulation results provide a better method for the robot’s workspace analyzing;Finally, the simulation experiment showed that the method we presented above could provide a good support for the multi-motion mode bionic quadruped robot walking smoothly and automatically.
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Li, Cai Lin, and Xin Wang Sun. "A Research of Reactive Compensation Scheme Based on the Hybrid Parallel Mode of SVG and PPF." Applied Mechanics and Materials 556-562 (May 2014): 3627–32. http://dx.doi.org/10.4028/www.scientific.net/amm.556-562.3627.
Повний текст джерелаАнотація:
A kind of hybrid parallel compensation scheme combining active compensation and passive compensation technology was proposed in this paper. The regulating function of reactive power can be realized dynamically and smoothly by means of integrating Static Var Generator (SVG) with passive filter (PPF) and then paralleling with the system load side bus. The harmonic current and voltage in the system could be filtered out. The calculation method of total compensation capacity, the determination method of SVG compensation capacity and the design method of PPF filter branches has been presented. Simulation result has proved that this scheme can achieve reactive power compensation and complete harmonic governance at the same time. Besides, the problems of reactive power and harmonic in the power system can be solved effectively, and the good engineering practical value is obvious. Figure 1 Hybrid parallel compensation structure diagram of SVG and PPF
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Chen, Po-Tuan, Cheng-Jung Yang, and Kuohsiu David Huang. "Dynamic Simulation and Control of a New Parallel Hybrid Power System." Applied Sciences 10, no. 16 (August 7, 2020): 5467. http://dx.doi.org/10.3390/app10165467.
Повний текст джерелаАнотація:
To avoid unnecessary power loss during switching between the various power sources of a composite electric vehicle while achieving smooth operation, this study focuses on the development and dynamic simulation analysis of a control system for the power of a parallel composite vehicle. This system includes a power integration and distribution mechanism, which enables the two power sources of the internal combustion engine and electric motor to operate independently or in coordination to meet the different power-output requirements. The integration of the electric motor and battery-charging engine reduces the system complexity. To verify the working efficiency of the energy control strategy for the power system, the NEDC2000 cycle is used for the vehicle driving test, a fuzzy logic controller is established using Matlab/Simulink, and the speed and torque analysis of the components related to power system performance are conducted. Through a dynamic simulation, it is revealed that this fuzzy logic controller can adjust the two power sources (the motor and internal combustion engine) appropriately. The internal combustion engine can be maintained in the optimal operating region with low, medium, and high driving speeds.
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Minh, V. T., F. B. Mohd Hashim, and M. Awang. "Development of a real-time clutch transition strategy for a parallel hybrid electric vehicle." Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 226, no. 2 (September 9, 2011): 188–203. http://dx.doi.org/10.1177/0959651811414760.
Повний текст джерелаАнотація:
The present paper develops a real-time clutch transition strategy for a parallel hybrid electric vehicle (HEV) in order to achieve quick and smooth clutch transition engagements between pure electrical driving and hybrid driving. Model predictive control (MPC) has been used for this model and tested with different control horizons and weighting factors to verify the ability of MPC to control the vehicle speeds for the clutch engagement. Some modified MPC algorithms with softened constraints and with output regions have been also studied to improve the robustness and the ability of this controller. Comprehensive simulations for the HEV have been conducted in MATLAB and Simulink. Results show that the system can provide real-time optimal control actions subject to input and output constraints for real-time clutch transition engagement with high driving comfort. The system can be implemented in electronic control units and applied for real HEVs.
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Fritz, Uwe, L. Lee Grismer, and Marika Asztalos. "Hybrid zones of Natrix helvetica and N. natrix: Phenotype data from iNaturalist and genetics reveal concordant clines and the value of species-diagnostic morphological traits." Vertebrate Zoology 73 (April 25, 2023): 383–95. http://dx.doi.org/10.3897/vz.73.e103319.
Повний текст джерелаАнотація:
Using georeferenced photographic records of 2944 grass snakes from Germany, Austria, and northern Italy as well as previously published mtDNA sequences (n = 1062) and microsatellite data (n = 952) for grass snakes from the same regions, we examined whether or not coloration and pattern reliably allow to differentiate between Natrix natrix and N. helvetica and if so, whether the distribution patterns revealed by phenotypes and genetics are congruent. Furthermore, we used cline analyses across hybrid zones to test whether the phenotypic transition from one species to the other parallels the steep clines unveiled by genetics. Our results suggest that the two species can be reliably differentiated using coloration and pattern. The most powerful diagnostic traits are the presence/absence of side bars on the body flanks, the number of occipital spots, and the shape of the posterior dark occipital spot. The distributions of morphologically identified N. natrix and N. helvetica match their genetically confirmed ranges. Single conflicting individuals morphologically identified as N. natrix or hybrids within the distribution range of N. helvetica either represent misidentifications or translocated snakes. For the genetic markers and phenotypes, our cline analyses revealed concordant steep clines across hybrid zones. However, the southern part of the hybrid zone in Italy, for which no sufficient genetic data are available, should be studied in more detail because the phenotypic data suggest a smooth cline in this region. The unexpected high percentage of putative hybrids with dorsal stripes in this region also calls for further research. For northwestern Germany, another region for which no genetically verified records are available, iNaturalist data suggest that the contact zone of N. natrix and N. helvetica is near the Ems River and extends from there southeastwards to the region of Höxter, North Rhine-Westphalia.
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Zhao, Zhiyuan, and Qilong Yuan. "Integrated Scheduling of the Production and Maintenance of Parallel Machine Job-shop Considering Stochastic Machine Breakdowns." Journal of Engineering Management and Systems Engineering 1, no. 1 (November 30, 2022): 15–22. http://dx.doi.org/10.56578/jemse010103.
Повний текст джерелаАнотація:
The integrated scheduling of production and maintenance can make equipment maintenance in line with the production pace, so as to effectively prevent anormal interruptions of the production process due to equipment failure, and ensure the smooth implementation of the production scheduling plan. Aiming at the parallel machine job-shop environment, and considering stochastic machine failures and different degradation speeds of parallel machines, this paper introduced the minimal maintenance and preventive maintenance strategies to establish an integrated scheduling model for production and maintenance, designed a genetic algorithm based on process coding and binary hybrid coding to solve the model, and verified the correctness of the proposed model and the effectiveness of the algorithm through an instance. This study provided an effective decision-making method for parallel machine job-shop scheduling problems.
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Krishnan, Megha G., Abhilash T. Vijayan, and Ashok Sankar. "Performance enhancement of two-camera robotic system using adaptive gain approach." Industrial Robot: the international journal of robotics research and application 47, no. 1 (November 4, 2019): 45–56. http://dx.doi.org/10.1108/ir-08-2019-0174.
Повний текст джерелаАнотація:
Purpose This paper aims to improve the performance of a two-camera robotic feedback system designed for automatic pick and place application by modifying its velocity profile during switching of control. Design/methodology/approach Cooperation of global and local vision sensors ensures visibility of the target for a two-camera robotic system. The master camera, monitoring the workspace, guides the robot such that image-based visual servoing (IBVS) by the eye-in-hand camera transcends its inherent shortcomings. A hybrid control law steers the robot until the system switches to IBVS in a region proven for its asymptotic stability and convergence through a qualitative overview of the scheme. Complementary gain factors can ensure a smooth transition in velocity during switching considering the versatility and range of the workspace. Findings The proposed strategy is verified through simulation studies and implemented on a 6-DOF industrial robot ABB IRB 1200 to validate the practicality of adaptive gain approach while switching in a hybrid visual feedback system. This approach can be extended to any control problem with uneven switching surfaces or coarse/fine controllers which are subjected to discrete time events. Practical implications In complex workspace where robots operate in parallel with other robots/humans and share workspaces, the supervisory control scheme ensures convergence. This study proves that hybrid control laws are more effective than conventional approaches in unstructured environments and visibility constraints can be overcome by the integration of multiple vision sensors. Originality/value The supervisory control is designed to combine the visual feedback data from eye-in-hand and eye-to-hand sensors. A gain adaptive approach smoothens the velocity characteristics of the end-effector while switching the control from master camera to the end-effector camera.
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Huynh, Ba-Phuc, and Yong-Lin Kuo. "Dynamic Hybrid Filter for Vision-Based Pose Estimation of a Hexa Parallel Robot." Journal of Sensors 2021 (October 16, 2021): 1–16. http://dx.doi.org/10.1155/2021/9990403.
Повний текст джерелаАнотація:
One of the problems with industrial robots is their ability to accurately locate the pose of the end-effector. Over the years, many other solutions have been studied including static calibration and dynamic positioning. This paper presents a novel approach for pose estimation of a Hexa parallel robot. The vision system uses three simple color feature points fixed on the surface of the end-effector to measure the pose of the robot. The Intel RealSense Camera D435i is used as a 3D measurement of feature points, which offers a cheap solution and high accuracy in positioning. Based on the constraint of three color feature points, the pose of the end-effector, including position and orientation, is determined. A dynamic hybrid filter is designed to correct the vision-based pose measurement. The complementary filter is used to eliminate the noise of image processing due to environmental light source interference. The unscented Kalman filter is designed to smooth out the pose estimation of the vision system based on robot’s kinematic parameters. The combination of two filters in the same control scheme contributes to increased stability and improved accuracy of robot’s positioning. The simulation, experiment, and comparison demonstrate the effectiveness and feasibility of the proposed method.
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Fu, Jiangtao, Shuzhong Song, Zhumu Fu, and Jianwei Ma. "Design of coordinated control strategy during driving mode switching for parallel hybrid electric vehicles." Transactions of the Institute of Measurement and Control 41, no. 9 (November 22, 2018): 2507–20. http://dx.doi.org/10.1177/0142331218803669.
Повний текст джерелаАнотація:
Hybrid electric vehicles (HEVs) require the power to drive the vehicle via a combination of internal combustion engine (ICE) and electric machine (EM). To improve the drivability, the smooth torque change during the driving mode switching is essential. This task can be achieved by using the coordinated control strategy. This paper presents a coordinated control strategy based on considering the different dynamic response characteristics of the ICE and the EM, which can effectively suppress the torque surge during the driving mode switching processes. The novelty lies in the proposed control is a motor active synchronization control strategy without clutch disengagement based on the mode switching classification. The coordinated control strategy is designed according to the classification of the driving modes. The objective is to minimize torque fluctuation and maintain or improve the driving performance of the vehicle. Results from the computer simulation demonstrate the effectiveness of this approach in reducing the torque surge without sacrificing vehicle performance.
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Al-Araji, Ahmed Sabah, and Shaymaa Jafe'er Al-Zangana. "Design of New Hybrid Neural Controller for Nonlinear CSTR System based on Identification." Journal of Engineering 25, no. 4 (April 1, 2019): 70–89. http://dx.doi.org/10.31026/j.eng.2019.04.06.
Повний текст джерелаАнотація:
This paper proposes improving the structure of the neural controller based on the identification model for nonlinear systems. The goal of this work is to employ the structure of the Modified Elman Neural Network (MENN) model into the NARMA-L2 structure instead of Multi-Layer Perceptron (MLP) model in order to construct a new hybrid neural structure that can be used as an identifier model and a nonlinear controller for the SISO linear or nonlinear systems. Two learning algorithms are used to adjust the parameters weight of the hybrid neural structure with its serial-parallel configuration; the first one is supervised learning algorithm based Back Propagation Algorithm (BPA) and the second one is an intelligent algorithm namely Particle Swarm Optimization (PSO) algorithm. The numerical simulation results show that the hybrid NARMA-L2 controller with PSO algorithm is more accurate than BPA in terms of achieving fast learning and adjusting the parameters model with minimum number of iterations, minimum number of neurons in the hybrid network and the smooth output one step ahead prediction controller response for the nonlinear CSTR system without oscillation.
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Ding, Jingang, and Xiaohong Jiao. "A Novel Control Method of Clutch During Mode Transition of Single-Shaft Parallel Hybrid Electric Vehicles." Electronics 9, no. 1 (December 30, 2019): 54. http://dx.doi.org/10.3390/electronics9010054.
Повний текст джерелаАнотація:
The mode transition of single-shaft parallel hybrid electric vehicles (HEVs) between engine and motor has an important impact on power and drivability. Especially, in the process of mode transition from the pure motor-drive operating mode to the only engine-drive operating mode, the motor starting engine and the clutch control problem have an important influence on driving quality, and solutions have a bit of room for improving dynamic performance. In this paper, a novel mode transition control method is proposed to guarantee a fast and smooth mode transition process in this regard. First, an adaptive sliding mode control (A-SMC) strategy is presented to obtain the desired torque trajectory of the clutch transmission. Second, a proportional-integral (PI) observer is designed to estimate the actual transmission torque of the clutch. Meanwhile, a fractional order proportional-integral-differential (FOPID) controller with the optimized control parameters by particle swarm optimization (PSO) is employed to realize the accurate position tracking of the direct current (DC) motor clutch so as to ensure clutch transmission torque tracking. Finally, the effectiveness and adaptability to system parameter perturbation of the proposed control approach are verified by comparison with the traditional control strategy in a MATLAB environment. The simulation results show that the driving quality of the closed-loop system using the proposed control approach is obviously improved due to fast and smooth mode transition process and better adaptability.
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Patil, Shanawaz, A. A. Pasha, Madeva Nagaral, B. S. Raju, and L. H. Manjunath. "Effect of beryl and graphene nano platelets reinforcements on the wear behaviour of AL7075- beryl graphene particulate hybrid nano composites." Journal of Mines, Metals and Fuels 69, no. 12A (April 28, 2022): 84. http://dx.doi.org/10.18311/jmmf/2021/30100.
Повний текст джерелаАнотація:
The effect of beryl particles and graphene nano platelets (GNPs) on the wear behaviour of Al7075-beryl-graphene hybrid composites has been studied. The hybrid composites were developed containing Al7075 matrix as matrix materials and 6 weight percentage of beryl and varying 0.5 to 2 weight percentage of graphene by using novel two step stir casting technique and wear behaviour of the newly developed hybrid composites were studied. The dry sliding wear studies conducted using a pin-on-disc tribo-tester under atmospheric conditions revealed that the wear loss of Al7075-beryl-graphene hybrid composites are lower than that of the matrix Al7075 alloy and further with increasing weight percentage of graphene decreased the wear loss of the hybrid composites. The wear studies also showed that the increase in load, sliding speed and sliding distance, the wear loss of the composites increased. The microstructure of the worn out surface revealed that a huge amount of plastic deformation appeared on the unreinforced Al7075 alloy when compared to the reinforced hybrid composites. The incorporation of beryl and graphene into Al7075 showed worn out surface that is not smooth and grooves, scratches and parallel lines were observed. The addition of beryl and GNPs into the matrix reduces erosion and small grooves like structure were noticed in the hybrid composites which leads to a reduction in wear in Al7075-beryl-GNPs hybrid composites
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Li, Guoqiang, and Daniel Görges. "Optimal integrated energy management and shift control in parallel hybrid electric vehicles with dual-clutch transmission." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 234, no. 2-3 (June 18, 2019): 599–609. http://dx.doi.org/10.1177/0954407019857419.
Повний текст джерелаАнотація:
This paper addresses the integration of the energy management and the shift control in parallel hybrid electric vehicles with dual-clutch transmission to reduce the fuel consumption, decrease the pollutant emissions, and improve the driving comfort simultaneously. Dynamic programming with a varying weighting factor in the cost function is proposed to balance the shift frequency and the fuel consumption for the power-split control and gear schedule design. Simulation results present that the drivability can be improved with a varying weighting factor due to fewer shift events while the fuel consumption is only slightly increased compared to dynamic programming with a constant weighting factor. A shift-energy-management strategy integrating the upshift and power-split control based on a multi-objective optimization is presented where model predictive control is employed to ensure engine load rate constraints. The strategy can smoothen the engine torque through torque compensation from the electric motor to prevent engine transient emissions resulting from a sudden load change. In a simulation study, the NOx and HC emissions could be reduced by 1.4% and 2.6% with 2% increase of the overall fuel consumption for the Federal Test Procedure 75 by smoothening the engine torque. For the New European Driving Cycle, 0.9% and 1.1% reduction of NOx and HC emissions could be achieved with only 0.3% more fuel consumption.
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Xie, Jun, Li Hui Kuang, and Yi Zhang. "Kinematic Analysis of a Novel Hybrid Chinese Medical Massage Robot." Key Engineering Materials 464 (January 2011): 123–28. http://dx.doi.org/10.4028/www.scientific.net/kem.464.123.
Повний текст джерелаАнотація:
The kinematics and dynamics characteristics of Chinese medical massage manipulation, such as pressing, kneading, rolling and pushing are studied. Based on the results of this analysis, the serial mechanical arm with six rotational joints and the end actuator with 3-DOF parallel mechanism are selected, and a new type of hybrid massage robot is proposed. The kinematic equation of the robot is set up through the D-H transformation matrix in D-H coordinate system. The direct and inverse kinematic solutions of the mechanical arm are calculated. Through the introduction of the arm-shaped mark, the inverse solution becomes unique. This shows that this mechanical arm can be in good control. The virtual prototype of this mechanical arm is built by Pro/E, and it is input to ADAMS from Mechanical/Pro. The movement simulation of the virtual prototype shows that the kinematic equation of the robot is right and this kind of hybrid massage robot can simulate the massage manipulation with very well smooth movement characteristics.
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Lechelek, Loubna, Sebastien Horna, Rita Zrour, Mathieu Naudin, and Carole Guillevin. "A Hybrid Method for 3D Reconstruction of MR Images." Journal of Imaging 8, no. 4 (April 7, 2022): 103. http://dx.doi.org/10.3390/jimaging8040103.
Повний текст джерелаАнотація:
Three-dimensional surface reconstruction is a well-known task in medical imaging. In procedures for intervention or radiation treatment planning, the generated models should be accurate and reflect the natural appearance. Traditional methods for this task, such as Marching Cubes, use smoothing post processing to reduce staircase artifacts from mesh generation and exhibit the natural look. However, smoothing algorithms often reduce the quality and degrade the accuracy. Other methods, such as MPU implicits, based on adaptive implicit functions, inherently produce smooth 3D models. However, the integration in the implicit functions of both smoothness and accuracy of the shape approximation may impact the precision of the reconstruction. Having these limitations in mind, we propose a hybrid method for 3D reconstruction of MR images. This method is based on a parallel Marching Cubes algorithm called Flying Edges (FE) and Multi-level Partition of Unity (MPU) implicits. We aim to combine the robustness of the Marching Cubes algorithm with the smooth implicit curve tracking enabled by the use of implicit models in order to provide higher geometry precision. Towards this end, the regions that closely fit to the segmentation data, and thus regions that are not impacted by reconstruction issues, are first extracted from both methods. These regions are then merged and used to reconstruct the final model. Experimental studies were performed on a number of MRI datasets, providing images and error statistics generated from our results. The results obtained show that our method reduces the geometric errors of the reconstructed surfaces when compared to the MPU and FE approaches, producing a more accurate 3D reconstruction.
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Pulloquinga, José L., Rafael J. Escarabajal, Jesús Ferrándiz, Marina Vallés, Vicente Mata, and Mónica Urízar. "Vision-Based Hybrid Controller to Release a 4-DOF Parallel Robot from a Type II Singularity." Sensors 21, no. 12 (June 13, 2021): 4080. http://dx.doi.org/10.3390/s21124080.
Повний текст джерелаАнотація:
The high accuracy and dynamic performance of parallel robots (PRs) make them suitable to ensure safe operation in human–robot interaction. However, these advantages come at the expense of a reduced workspace and the possible appearance of type II singularities. The latter is due to the loss of control of the PR and requires further analysis to keep the stiffness of the PR even after a singular configuration is reached. All or a subset of the limbs could be responsible for a type II singularity, and they can be detected by using the angle between two output twist screws (OTSs). However, this angle has not been applied in control because it requires an accurate measure of the pose of the PR. This paper proposes a new hybrid controller to release a 4-DOF PR from a type II singularity based on a real time vision system. The vision system data are used to automatically readapt the configuration of the PR by moving the limbs identified by the angle between two OTSs. This controller is intended for a knee rehabilitation PR, and the results show how this release is accomplished with smooth controlled movements where the patient’s safety is not compromised.
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Zizoui, Mohamed Zine, Muhammad Fahad Zia, Bekheira Tabbache, Yassine Amirat, Abdeslam Mamoune, and Mohamed Benbouzid. "Photovoltaic-Battery-Ultracapacitor-Diesel Hybrid Generation System for Mobile Hospital Energy Supply." Electronics 11, no. 3 (January 27, 2022): 390. http://dx.doi.org/10.3390/electronics11030390.
Повний текст джерелаАнотація:
This paper deals with the energy management of a hybrid power system, which consists of a photovoltaic (PV) system, diesel generators, battery, and ultracapacitor for a mobile hospital. The proposed power system can supply energy to shelter hospitals for better treatment of patients in remote states, particularly in the event of a pandemic situation such as Coronavirus Disease 2019 (COVID-19). For this reason, a hybrid power system in which a diesel generator is used with a photovoltaic energy source for reliable availability of power supply. Moreover, battery and ultracapacitor are also integrated to obtain a hybrid power generation and storage system to ensure the smooth operation of mobile hospitals irrespective of weather conditions. A boost converter is used with PV panels to operate them in either maximum power tracking mode or power curtailment mode. The battery is connected to a bidirectional reversible DC-DC converter for direct-current (DC) bus voltage regulation and state of charge control. The ultracapacitor is associated with the battery to compensate for the peak power. The diesel generator is connected in parallel with the photovoltaic generator, battery, and ultracapacitor to continuously provide the power required by the load. The integrated operation of all generation sources and storage systems is complex for shelter hospitals. Therefore, an efficient energy management algorithm is developed to manage the continuous energy flow between different elements of the hybrid power system and mobile hospital load through the control of the power converters. Finally, validation results are presented to show the effectiveness of the proposed energy management algorithm for the hybrid power system.
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Mutarraf, Muhammad, Yacine Terriche, Niazi, Fawad Khan, Juan Vasquez, and Josep Guerrero. "Control of Hybrid Diesel/PV/Battery/Ultra-Capacitor Systems for Future Shipboard Microgrids." Energies 12, no. 18 (September 7, 2019): 3460. http://dx.doi.org/10.3390/en12183460.
Повний текст джерелаАнотація:
In recent times, concerns over fossil fuel consumption and severe environmental pollution have grabbed attention in marine vessels. The fast development in solar technology and the significant reduction in cost over the past decade have allowed the integration of solar technology in marine vessels. However, the highly intermittent nature of photovoltaic (PV) modules might cause instability in shipboard microgrids. Moreover, the penetration is much more in the case of utilizing PV panels on ships due to the continuous movement. This paper, therefore, presents a frequency sharing approach to smooth the effect of the highly intermittent nature of PV panels integrated with the shipboard microgrids. A hybrid system based on an ultra-capacitor and a lithium-ion battery is developed such that high power and short term fluctuations are catered by an ultra-capacitor, whereas long duration and high energy density fluctuations are catered by the lithium-ion battery. Further, in order to cater for the fluctuations caused by weather or variation in sea states, a battery energy storage system (BESS) is utilized in parallel to the dc-link capacitor using a buck-boost converter. Hence, to verify the dynamic behavior of the proposed approach, the model is designed in MATLAB/SIMULINK. The simulation results illustrate that the proposed model helps to smooth the fluctuations and to stabilize the DC bus voltage.
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Krivošej, Jan, and Zbyněk Šika. "Optimization and Control of a Planar Three Degrees of Freedom Manipulator with Cable Actuation." Machines 9, no. 12 (December 7, 2021): 338. http://dx.doi.org/10.3390/machines9120338.
Повний текст джерелаАнотація:
The paper analyzes a planar three degrees of freedom manipulator with cable actuation. Such a system can be understood as a special type of hybrid parallel kinematic mechanism composed of the rigid serial chain and the additional auxiliary cable system. The advantage of the auxiliary cable mechanism is the ability to reconfigure the whole system. The fulfillment of sufficient prestressing is the constraint of the optimization process. Computed Torque Control with a cable force distribution algorithm is implemented. The control algorithm performance is examined on different trajectories, including non-smooth motion requests, and its robustness is tested by randomly generated errors of the model parameters in regulators. The results demonstrate that the optimized structure is capable of controlling the manipulator motion and keeping the cable prestressing within the given limits.
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Hu, Ban Zan, Qing Feng Wang, Hong Mei Wang, and Hong Yao. "Study on Control of the Rotational Speed of Diesel Engine under State-Switch Mode in Parallel Hybrid Hydraulic Excavator." Applied Mechanics and Materials 290 (February 2013): 97–106. http://dx.doi.org/10.4028/www.scientific.net/amm.290.97.
Повний текст джерелаАнотація:
In parallel hybrid hydraulic excavator (PHHE) with super capacitor, the throttle position of the diesel engine is changed with the variation of the capacitor’s state of charge (SOC) of the super capacitor. When the throttle position is switched, the rotational speed of the diesel engine cannot be able to increase or decrease to the target speed rapidly enough, and it may fluctuate in large range under given conditions. Under the assumption that the loading torque of the diesel engine is invariant at the switch instant, the response of the rotational speed appears to be in different forms, which are not admitted for the normal work of PHHE. In this paper, switch types are divided into eight state-switch modes, in terms of the loading type and the amplitude of variation of the throttle position. And the paper mainly aims to the smooth transition of the rotational speed during the switched process of PHHE by the dynamic compensation of the electric motor. Experimental results show that the dynamic compensation of the electric motor can improve the dynamic behavior when PHHE is under state-switch modes.
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Guo, Fei, Shoukun Wang, Binkai Yue, and Junzheng Wang. "A Deformable Configuration Planning Framework for a Parallel Wheel-Legged Robot Equipped with Lidar." Sensors 20, no. 19 (October 1, 2020): 5614. http://dx.doi.org/10.3390/s20195614.
Повний текст джерелаАнотація:
The wheel-legged hybrid robot (WLHR) is capable of adapting height and wheelbase configuration to traverse obstacles or rolling in confined space. Compared with legged and wheeled machines, it can be applied for more challenging mobile robotic exercises using the enhanced environment adapting performance. To make full use of the deformability and traversability of WHLR with parallel Stewart mechanism, this paper presents an optimization-driven planning framework for WHLR with parallel Stewart mechanism by abstracting the robot as a deformable bounding box. It will improve the obstacle negotiation ability of the high degree-of-freedoms robot, resulting in a shorter path through adjusting wheelbase of support polygon or trunk height instead of using a fixed configuration for wheeled robots. In the planning framework, we firstly proposed a pre-calculated signed distance field (SDF) mapping method based on point cloud data collected from a lidar sensor and a KD -tree-based point cloud fusion approach. Then, a covariant gradient optimization method is presented, which generates smooth, deformable-configuration, as well as collision-free trajectories in confined narrow spaces. Finally, with the user-defined driving velocity and position as motion inputs, obstacle-avoidancing actions including expanding or shrinking foothold polygon and lifting trunk were effectively testified in realistic conditions, demonstrating the practicability of our methodology. We analyzed the success rate of proposed framework in four different terrain scenarios through deforming configuration rather than bypassing obstacles.
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Don, Wai-Sun, Antonio de Gregorio, Jean-Piero Suarez, and Gustaaf B. Jacobs. "Assessing the Performance of a Three Dimensional Hybrid Central-WENO Finite Difference scheme with Computation of a Sonic Injector in Supersonic Cross Flow." Advances in Applied Mathematics and Mechanics 4, no. 06 (December 2012): 719–36. http://dx.doi.org/10.4208/aamm.12-12s03.
Повний текст джерелаАнотація:
AbstractA hybridization of a high order WENO-Zfinite difference scheme and a high order central finite difference method for computation of the two-dimensional Euler equations first presented in [B. Costa and W. S. Don, J. Comput. Appl. Math., 204(2) (2007)] is extended to three-dimensions and for parallel computation. The Hybrid scheme switches dynamically from a WENO-Zscheme to a central scheme at any grid location and time instance if the flow is sufficiently smooth and vice versa if the flow is exhibiting sharp shock-type phenomena. The smoothness of the flow is determined by a high order multi-resolution analysis. The method is tested on a benchmark sonic flow injection in supersonic cross flow. Increase of the order of the method reduces the numerical dissipation of the underlying schemes, which is shown to improve the resolution of small dynamic vortical scales. Shocks are captured sharply in an essentially non-oscillatory manner via the high order shock-capturing WENO-Zscheme. Computations of the injector flow with a WENO-Zscheme only and with the Hybrid scheme are in very close agreement. Thirty percent of grid points require a computationally expensive WENO-Zscheme for high-resolution capturing of shocks, whereas the remainder of grid points may be solved with the computationally more affordable central scheme. The computational cost of the Hybrid scheme can be up to a factor of one and a half lower as compared to computations with a WENO-Zscheme only for the sonic injector benchmark.
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Huang, Longnv, Qingyuan Wang, Jiehui Huang, Limin Chen, Yin Liang, Peter X. Liu, and Chunquan Li. "A Novel Hybrid Predictive Model for Ultra-Short-Term Wind Speed Prediction." Energies 15, no. 13 (July 4, 2022): 4895. http://dx.doi.org/10.3390/en15134895.
Повний текст джерелаАнотація:
A novel hybrid model is proposed to improve the accuracy of ultra-short-term wind speed prediction by combining the improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN), the sample entropy (SE), optimized recurrent broad learning system (ORBLS), and broadened temporal convolutional network (BTCN). First, ICEEMDAN is introduced to smooth the nonlinear part of the wind speed data by decomposing the raw wind speed data into a series of sequences. Second, SE is applied to quantitatively assess the complexity of each sequence. All sequences are divided into simple sequence set and complex sequence set based on the values of SE. Third, based on the typical broad learning system (BLS), we propose ORBLS with cyclically connected enhancement nodes, which can better capture the dynamic characteristics of the wind. The improved particle swarm optimization (PSO) is used to optimize the hyper-parameters of ORBLS. Fourth, we propose BTCN by adding a dilated causal convolution layer in parallel to each residual block, which can effectively alleviate the local information loss of the temporal convolutional network (TCN) in case of insufficient time series data. Note that ORBLS and BTCN can effectively predict the simple and complex sequences, respectively. To validate the performance of the proposed model, we conducted three predictive experiments on four data sets. The experimental results show that our model obtains the best predictive results on all evaluation metrics, which fully demonstrates the accuracy and robustness of the proposed model.
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Kuo, Hsien-Yu, and Tyng Liu. "On the Design of Continuously Variable Transmissions with Bidirectional Bridge Structures for Hybrid Vehicles." Applied Sciences 11, no. 6 (March 11, 2021): 2500. http://dx.doi.org/10.3390/app11062500.
Повний текст джерелаАнотація:
To increase the energy efficiency of road vehicles, an ideal transmission system should have a wide ratio coverage, a high torque capacity, and a high mechanical efficiency. Continuously variable units (CVUs) have been successfully implemented due to the smooth ratio variation, sufficient torque capacity, and ratio coverage. Hence, it will be beneficial to develop a hybrid powertrain comprising a CVU. In this paper, a design method called the “basic path diagram” (BPD) is proposed. It provides a simplified schematic of the system and represents the generic connections among the mechanical components. The system configurations synthesized by the BPD can be sorted according to three characteristics: Direction of power flows through the CVU, coupling pattern of the power inputs, and number of transmission paths parallel to the CVU. The first characteristic determines the number of times the CVU ratio coverage can be exploited, the second characteristic determines whether the torque of the power inputs can be independently controlled, and the third characteristic can help reduce the torque loading of the CVU. With the aid of a BPD, one of the possible system configurations is provided as an example. The result shows that the system can exploit twice the ratio coverage of the CVU and reduce the torque and power transmitted by the CVU in combination with planetary gearsets.
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Kanda, Keiichi, and Takehisa Matsuda. "Mechanical Stress-Induced Orientation and Ultrastructural Change of Smooth Muscle Cells Cultured in Three-Dimensional Collagen Lattices." Cell Transplantation 3, no. 6 (November 1994): 481–92. http://dx.doi.org/10.1177/096368979400300605.
Повний текст джерелаАнотація:
The effect of tensile stress on the orientation and phenotype of arterial smooth muscle cells (SMCs) cultured in three-dimensional (3D) type I collagen gels was morphologically investigated. Ring-shaped hybrid tissues were prepared by thermal gelation of a cold mixed solution of type I collagen and SMCs derived from bovine aorta. The tissues were subjected to three different modes of tensile stress. They were floated (isotonic control), stretched isometrically (static stress) and periodically stretched and recoiled by 5% above and below the resting tissue length at 60 RPM frequency (dynamic stress). After incubation for up to four wk, the tissues were investigated under a light microscope (LM) and a transmission electron microscope (TEM). Hematoxylin and eosinstained LM samples revealed that, irrespective of static or dynamic stress loading, SMCs in stress-loaded tissues exhibited elongated bipolar spindle shape and were regularly oriented parallel to the direction of the strain, whereas those in isotonic control tissues were polygonal or spherical and had no preferential orientation. In Azan-stained samples, collagen fiber bundles in isotonic control tissues were somewhat retracted around the polygonal SMCs to form a random network. On the other hand, those in statically and dynamically stressed tissues were accumulated and prominently oriented parallel to the stretch direction. Ultrastructural investigation using a TEM showed that SMCs in control and statically stressed tissues were almost totally filled with synthetic organelles such as rough endoplasmic reticulums, free ribosomes, Golgi complexes and mitochondria, indicating that the cells remained in the synthetic phenotype. On the other hand, SMCs in dynamically stressed tissues had increased fractions of contractile apparatus, such as myofilaments, dense bodies and extracellular filamentous materials equivalent to basement membranes, that progressed with incubation time. These results indicate that periodic stretch, in concert with 3-D extracellular collagen matrices, play a significant role in the phenotypic modulation of SMCs from the synthetic to the contractile state, as well as cellular and biomolecular orientation.
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Lei, Tongfei, Saleem Riaz, Noor Zanib, Munira Batool, Feng Pan, and Shaoguo Zhang. "Performance Analysis of Grid-Connected Distributed Generation System Integrating a Hybrid Wind-PV Farm Using UPQC." Complexity 2022 (March 18, 2022): 1–14. http://dx.doi.org/10.1155/2022/4572145.
Повний текст джерелаАнотація:
This work presents a distributed generation system (DG) that combines system of a wind turbine (WT) and photovoltaic (PV) using a unified power quality conditioner (UPQC). Along with providing active power (AP) to the utility grid, Wind-PV-UPQC improves PQ indicators, for example, voltage drops/surges, harmonics of grid voltages, and PF. Since Wind-PV-UPQC depends on dual compensation scheme, the parallel converter works as a sinusoidal voltage source, while the series converter works as a sinusoidal current source. In this way, a smooth transition from grid operation to island operation and vice versa can be achieved without load voltage transitions. In addition, in order to overcome the problems through abrupt solar radiation or wind speed variations, a faster power balance is achieved between the wind turbines, the PV array, and the grid, as FFCL pursue the production of the current references of series converter. Consequently, the dynamic reactions of the converter currents and the voltage of dc bus are enhanced. A comprehensive analysis of flow of the AP through the converters is done to ensure a proper understanding of how Wind-PV-UPQC works. Finally, the simulation results are shown to estimate the dynamic and static performance of Wind-PV-UPQC in conjunction with the power distribution system.
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Lin, Yu-Hsiu, Kai-Lung Hua, Yung-Yao Chen, I.-Ying Chen, and Yun-Chen Tsai. "A New Photographic Reproduction Method Based on Feature Fusion and Virtual Combined Histogram Equalization." Sensors 21, no. 18 (September 9, 2021): 6038. http://dx.doi.org/10.3390/s21186038.
Повний текст джерелаАнотація:
A desirable photographic reproduction method should have the ability to compress high-dynamic-range images to low-dynamic-range displays that faithfully preserve all visual information. However, during the compression process, most reproduction methods face challenges in striking a balance between maintaining global contrast and retaining majority of local details in a real-world scene. To address this problem, this study proposes a new photographic reproduction method that can smoothly take global and local features into account. First, a highlight/shadow region detection scheme is used to obtain prior information to generate a weight map. Second, a mutually hybrid histogram analysis is performed to extract global/local features in parallel. Third, we propose a feature fusion scheme to construct the virtual combined histogram, which is achieved by adaptively fusing global/local features through the use of Gaussian mixtures according to the weight map. Finally, the virtual combined histogram is used to formulate the pixel-wise mapping function. As both global and local features are simultaneously considered, the output image has a natural and visually pleasing appearance. The experimental results demonstrated the effectiveness of the proposed method and the superiority over other seven state-of-the-art methods.
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Parfenіuk, O. А., and S. H. Trush. "Performance potential of sugar beets with improved beetroot shape in breeding for heterosis." Plant Breeding and Seed Production, no. 119 (July 12, 2021): 34–43. http://dx.doi.org/10.30835/2413-7510.2021.236995.
Повний текст джерелаАнотація:
Purpose. To increase the performance of sugar beet hybrids using integrated approaches to the creation, identification and selection of combination-valuable parents; to evaluate the performance potential of experimental hybrids derived from parents with improved beetroot shape.
Materials and methods. The study was conducted in the Laboratory of Sugar Beet Breeding of the Tobacco Experimental Station of the National Research Center “Institute of Agriculture of NAAS” in 2018–2020. Sixty-six experimental diploid sugar beet hybrids originating from parents of different genetic origin were tested in the field.
New starting material of sugar beets was created using classical breeding methods and traditional techniques. The experimental CMS-based sugar beet hybrids were evaluated for several economically valuable traits in accordance with the variety trial method developed by scientists of the Institute of Bioenergy Crops and Sugar Beets NAAS.
Results and discussion. Analysis of the performance of the sugar beet hybrids originating from the parents with improved beetroot shape (oval-conical) indicates that the beetroot yields, sugar collection and output were significantly higher than those in the group check accession. The sugar content in their beetroots was lower than or similar to that in the group check accession. In general, the yielding type (E) of performance is intrinsic to the hybrids. As to beetroot yield, they exceeded the group check accession by 16.5–23.4%; the sugar collection was higher by 15.1–21.1%; and the sugar output – by 15.0–22.0%.
Analysis of the beetroot in these hybrids shows that they had oval-conical beetroots. Their shape index varied 1.11 to 1.24. The beetroots of these hybrids were embedded into the soil by 3/4 of their length, had a smooth surface and shallow grooves (orthostichy).
In the experimental sugar beet hybrids derived from the parents with improved beetroot shape (oval-conical), beetroots were longer (L) by 9.5%, larger in the diameter (D) by 2.2%, and the distance from the maximum diameter plane to the beetroot top (B) increased by 61.5% compared to the group check accession. In parallel with changes of the beetroot shape, the beetroot weight (m) increased by 25.0%. The transition from conical beetroots to oval-conical ones was proven to increase the performance of the sugar beet hybrids by 15–21%.
Conclusions. We have created 14 high-yielding sugar beet CMS-based hybrids with improved beetroot shape, suitable for energy and environmentally friendly cultivation technologies. Their beetroot yields, sugar collection and sugar output exceed those in the group check accession by 16.5–23.4%, 15.1–21.1% and 15.0–22.0%, respectively
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Tan, B.-K., K. Rudakov, V. P. Koshelets, A. Khudchenko, A. M. Baryshev, and G. Yassin. "Comparing the performance of 850 GHz integrated bias-tee superconductor-insulator-superconductor (SIS) mixers with single- and parallel-junction tuner." Superconductor Science and Technology 35, no. 12 (November 7, 2022): 125008. http://dx.doi.org/10.1088/1361-6668/ac9d6e.
Повний текст джерелаАнотація:
Abstract We present and compare the design and performance of two 850 GHz radial probe fed superconductor-insulator-superconductor mixers, where the antenna is aligned perpendicular to the E-Plane of the input full-height rectangular waveguide connected to a multiple flare-angles smooth-walled horn. Both designs are comprised of 0.5 µm2 hybrid niobium/aluminium-nitride/niobium-nitride tunnel junction, fabricated on top of a niobium titanium nitride ground plane with an Al wiring layer. The entire superconducting circuit is supported with a 40 µm thick quartz substrate. The major difference between the two designs is the method used to cancel out the parasitic junction capacitance for broadband performance. The first design utilises two identical junctions connected in parallel with a short transmission line to convert the capacitance of one junction into the equivalent inductance of the other junction, commonly known as the twin-junction tuning scheme; whilst the second design employs an end-loaded scheme with only one tunnel junction. We found that both methods offer similar radio frequency performances, with close to 2× the double sideband quantum noise temperature, but the twin-junction design is more resilient to fabrication tolerances. However, the end-loaded design offers a much better intermediate frequency (IF) bandwidth performance, made possible by the sub-micron and high current density tunnel junction technology. The improved IF performance is important for many millimetre (mm) and sub-mm observatories, such as future upgrades of Atacama Large Millimetre/sub-mm Array receivers, as well as forthcoming space-borne far-infrared missions. Therefore, we conclude that the single-junction mixer design is the preferred option for THz applications, as long as the fabrication error can be minimised within a certain limit.
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Anselma, Pier Giuseppe. "Dynamic Programming Based Rapid Energy Management of Hybrid Electric Vehicles with Constraints on Smooth Driving, Battery State-of-Charge and Battery State-of-Health." Energies 15, no. 5 (February 23, 2022): 1665. http://dx.doi.org/10.3390/en15051665.
Повний текст джерелаАнотація:
Dynamic programming (DP) is currently the reference optimal energy management approach for hybrid electric vehicles (HEVs). However, several research concerns arise regarding the effective application of DP for optimal HEV control problems which involve a significant number of control variables, state variables and optimization constraints. This paper deals with an optimal control problem for a full parallel P2 HEV with constraints on battery state-of-charge (SOC), battery lifetime in terms of state-of-health (SOH), and smooth driving in terms of the frequencies of internal combustion engine (ICE) activations and gear shifts over time. The DP formulation for the considered HEV control problem is outlined, yet its practical application is demonstrated as unfeasible due to a lack of computational power and memory in current desktop computers. To overcome this drawback, a computationally efficient version of DP is proposed which is named Slope-weighted Rapid Dynamic Programming (SRDP). Computational advantage is achieved by SRDP in considering only the most efficient HEV powertrain operating points rather than the full set of control variable values at each time instant of the drive cycle. A benchmark study simulating various drive cycles demonstrates that the introduced SRDP can achieve compliance with imposed control constraints on battery SOC, battery SOH and smooth driving. At the same time, SRDP can achieve up to 78% computational time saving compared with a baseline DP approach considering the Worldwide Harmonized Light Vehicle Test Procedure (WLTP). On the other hand, the increase in the fuel consumption estimated by SRDP is limited within 3.3% compared with the baseline DP approach if the US06 Supplemental Federal Test Procedure is considered. SRDP could thus be exploited to efficiently explore the large design space associated to HEV powertrains.
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Dariusz, Strąk. "Performance investigation of hybrid photovoltaic thermal-heat with mini-channels for application in electric vehicles." Archives of Automotive Engineering – Archiwum Motoryzacji 100, no. 2 (June 30, 2023): 1–26. http://dx.doi.org/10.14669/am/166810.
Повний текст джерелаАнотація:
The first autonomous car was developed in the 1980s, but it wasn't until the early 2010s that the technology began to gain significant attention and investment. In 2010, Google began testing self-driving cars on public roads, and since then, many other companies have joined the race to develop fully autonomous vehicles. Hybrid PVT (Photovoltaic Thermal) heat exchangers cooled with mini-channels find application in autonomous vehicles as a solution that enables efficient cooling of the vehicle's electronics and batteries. The solution involves using photovoltaic panels to generate electricity and removing the heat produced during the process using mini-channels is removed by mini-channels. Hybrid PVT heat exchangers cooled with mini-channels can help maintain appropriate temperatures inside autonomous vehicles that generate large amounts of heat from electronic systems and sensors. The setup can improve the performance and reliability of autonomous systems, increase energy efficiency, and reduce energy demands. The experimental setup includes two parallel mini-channel systems separated by a smooth copper plate. The study aims to determine local heat-transfer coefficients, with a cooled solar cell efficiency range of 10% to 14% compared to other research. The cooled PV temperature range achieved was from 19.6 to 22.4 degrees Celsius, which is favorable for photovoltaic panels' operation under approximate light intensity for Poland's latitude. Heat-transfer from hot surfaces to cold fluids is analyzed during single-phase convection using two calculation methods: one-dimensional and numerical simulations using Simcenter STAR CCM+. Cooling photovoltaic modules is critical for the photovoltaic and autonomous vehicle systems sector, making this research significant both theoretically and practically. The research and methods presented in the article on mini-channel cooling of photovoltaic systems and autonomous vehicle systems are innovative at a global scale, and are crucial for further development of sustainable energy systems and reduction of greenhouse gas emissions.
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Khan, Umair, Aurang Zaib, Anuar Ishak, Iskandar Waini, Javali K. Madhukesh, Zehba Raizah, and Ahmed M. Galal. "Impact of Buoyancy and Stagnation-Point Flow of Water Conveying Ag-MgO Hybrid Nanoparticles in a Vertical Contracting/Expanding Riga Wedge." Symmetry 14, no. 7 (June 24, 2022): 1312. http://dx.doi.org/10.3390/sym14071312.
Повний текст джерелаАнотація:
Riga surface can be utilized to reduce the pressure drag and the friction of the submarine by stopping the separation of the boundary layer as well as by moderating turbulence production. Therefore, the current symmetry of the work investigates the slip impacts on mixed convection flow containing water-based hybrid Ag-MgO nanoparticles over a vertical expanding/contracting Riga wedge. In this analysis, a flat surface, wedge, and stagnation point are also discussed. A Riga surface is an actuator that contains electromagnetic where a span-wise array associated with the permanent magnets and irregular electrodes accumulated on a smooth surface. A Lorentz force is incorporated parallel to the surface produced by this array which eases exponentially normal to the surface. Based on the considered flow symmetry, the physical scenario is initially modeled in the appearance of partial differential equations which are then rehabilitated into a system of ordinary differential equations by utilizing the pertinent similarity variables. A bvp4c solver is engaged to acquire the numerical solution. The flow symmetry and the influences of pertaining parameters involved in the problem are investigated and are enclosed in graphical form. The findings confirm that the velocity reduces, and temperature enhances due to nanoparticle volume fraction. A modified Hartmann number increases the velocity and diminishes the temperature. Moreover, the suction parameter enhances the velocity profiles and reduces the dimensionless temperature profiles. The heat transfer gradually increases by diminishing the contracting parameter and increasing the expanding parameter.
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Liu, Yu, Lianghua Huang, Pan Pan, Bin Wang, Yinghui Xu, and Rong Jin. "Train a One-Million-Way Instance Classifier for Unsupervised Visual Representation Learning." Proceedings of the AAAI Conference on Artificial Intelligence 35, no. 10 (May 18, 2021): 8706–14. http://dx.doi.org/10.1609/aaai.v35i10.17055.
Повний текст джерелаАнотація:
This paper presents a simple unsupervised visual representation learning method with a pretext task of discriminating all images in a dataset using a parametric, instance-level classifier. The overall framework is a replica of a supervised classification model, where semantic classes (e.g., dog, bird, and ship) are replaced by instance IDs. However, scaling up the classification task from thousands of semantic labels to millions of instance labels brings specific challenges including 1) the large-scale softmax computation; 2) the slow convergence due to the infrequent visiting of instance samples; and 3) the massive number of negative classes that can be noisy. This work presents several novel techniques to handle these difficulties. First, we introduce a hybrid parallel training framework to make large-scale training feasible. Second, we present a raw-feature initialization mechanism for classification weights, which we assume offers a contrastive prior for instance discrimination and can clearly speed up converge in our experiments. Finally, we propose to smooth the labels of a few hardest classes to avoid optimizing over very similar negative pairs. While being conceptually simple, our framework achieves competitive or superior performance compared to state-of-the-art unsupervised approaches, i.e., SimCLR, MoCoV2, and PIC under ImageNet linear evaluation protocol and on several downstream visual tasks, verifying that full instance classification is a strong pretraining technique for many semantic visual tasks.
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Nandede, Aniket H., Yogesh K. Bhateshwar, and Kamal C. Vora. "Development of EMS for Hybrid Electric Two-Wheeler." International Journal of Engineering Sciences 15, no. 1 (2022). http://dx.doi.org/10.36224/ijes.150105.
Повний текст джерелаАнотація:
Rising the emission level from conventional vehicles (CV) is a major concern of today’s world. Electric vehicle (EV) and hybrid electric vehicles (HEV) technology are two ways to deal with it. EV technology is an emerging technology but they have some challenges in adopting the EV technology. So, this paper deals with modelling and simulation of a hybrid electric vehicle such as series hybrid electric vehicle and parallel hybrid electric vehicle with different energy management strategies. The heart of HEV development is energy management strategy (EMS), on which vehicle’s performance and fuel consumption can be optimized. For series HEV charge depleting charge sustaining (CDCS) EMS has been used and for parallel HEV rule-based (RB) EMS has been used. Supervisory control algorithms play important role to allow smooth power flow between the engine and electric source. There are different EMSs such as rule-based, optimization-based (OB), and learning-based (LB). These EMSs are used to split the power flow. In this paper, fuzzy logic controller (FLC) as an energy management strategy is proposed for a parallel hybrid electric vehicle, further this strategy is compared with RBEMS. The simulation results are compared and analyzed which shows there is improvement in range and reduction fuel consumption. In this study, MATLAB/Simulink and QSS toolbox are used for the simulation.
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Canova, Marcello, Yann Guezennec, and Steve Yurkovich. "On the Control of Engine Start/Stop Dynamics in a Hybrid Electric Vehicle." Journal of Dynamic Systems, Measurement, and Control 131, no. 6 (November 1, 2009). http://dx.doi.org/10.1115/1.4000066.
Повний текст джерелаАнотація:
The starter/alternator technology is considered an easily realizable hybrid electric vehicle (HEV) configuration to achieve significant fuel economy without compromising consumer acceptability. Several examples can be found in production or near-production vehicles, with implementation based on a spark ignition (SI) engine coupled with either a belted starter/alternator (BSA) or an integrated starter/alternator (ISA). One of the many challenges in successfully developing a starter/alternator HEV is to achieve engine start and stop operations with minimum passenger discomfort. This requires control of the electric motor to start and stop the engine quickly and smoothly, without compromising the vehicle noise, vibration, and harshness signature. The issue becomes more critical in the case of diesel hybrids, as the peak compression torque is much larger than in SI engines. This paper documents the results of a research activity focused on the control of the start and stop dynamics of a HEV with a belted starter/alternator. The work was conducted on a production 1.9 l common-rail diesel engine coupled to a 10.6 kW permanent magnet motor. The system is part of a series/parallel HEV powertrain, designed to fit a midsize prototype sport utility vehicle. A preliminary experimental investigation was done to assess the feasibility of the concept and to partially characterize the system. This facilitated the design of a control-oriented nonlinear model of the system dynamics and its validation on the complete HEV hardware. Model-based control techniques were then applied to design a controller for the belted starter/alternator, ensuring quick and smooth engine start operations. The final control design has been implemented on the vehicle. The research outcomes demonstrated that the BSA is effective in starting the diesel engine quickly and with very limited vibration and noise.
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Kassa Mersha, Tewodros, and Changqing Du. "Active damping control of HEVs using Ansys and Matlab/Simulink software." Journal of Vibroengineering, July 27, 2022. http://dx.doi.org/10.21595/jve.2022.22511.
Повний текст джерелаАнотація:
This paper presents Parallel Hybrid Electric Vehicles (HEVs) powertrain design as well as a motor-based control approach that is designed to control or reduce driveline oscillations by introducing a Proportional-Integral-Derivative (PID) controller and a Fuzzy logic sliding mode controller. Because the torque of the electric motor can be decreased or increased more quickly than that of the Internal Combustion Engine (ICE), the vibration increases significantly. To solve this problem, an electric motor control-based Active Damping Control (ADC) strategy is employed to assure smooth driveline function and provide seamless driving experience for the driver. First, the basic level modeling of a hybrid electric powertrain in Ansys Simplorer environment is created and the performance was studied during the certification drive cycle. Thus, the main components of the powertrain– traction motor, battery and ICE – are researched, and basic models were built. The components were developed based on the Ansys software by using an automotive system level behavioral HEV library with VHDL-AMS language built in Ansys Simplorer environment. In addition, comparison of both controllers was presented. The simulation results show that using the ADC reduces more than 30 % of the driveline oscillations, thereby improving the drivability of HEVs.
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"Preface." IOP Conference Series: Earth and Environmental Science 955, no. 1 (January 1, 2022): 011001. http://dx.doi.org/10.1088/1755-1315/955/1/011001.
Повний текст джерелаАнотація:
Excellency, Drs. Bedjo Santoso, MT. Ph. D., Rector Universitas Islam Sultan Agung; Honorable, Assoc. Prof. Dr. Mohd Ismid Bin Md Said, Pro-Vice Chancellor (International) UTM; Respectable, The distinguished guests and the participants, ladies and gentlemen. Welcome to the International Forum on Integrated Infrastructure Development (InFInID 2021) Hybrid Conference, which consists of 12th International Conference on Geotechnical Engineering in Tropical Regions (GEOTROPIKA), 2nd International Conference on Highway and Transportation Engineering (ICHITRA), and The 4th International Conference on Delta & Coastal Areas (ICCDA 4 2021), 21–22 September 2021. Due to the global health issue of coronavirus disease (COVID-19), InFInID 2021 is being held in mixed mode, offline and online. The conference is divided to Panel and Parallel session (7 parallel sessions, 3 rooms for 3 fields per session). I also want to inform that we will have ‘Best Paper’ Award for some topics and ‘Best Presenter’ Award for each session. For all presenters, do your best and catch the reward. The next step is publishing all paper to IOP Conference Series: Earth and Environmental Science, Scopus Index. May the conference run smoothly and the goals will be achieved. And last, but not least, I would like to thank you, our shareholders, for continuing to support us, in good times, and in difficult ones. Hope that the pandemic will leave us soon, and we will have the opportunity to meet again face to face. My best wishes to you all! Prof. Dr. Ir. S. Imam Wahyudi, DEA Chairman of ICCDA 4 List of Patrons, Advisors, Chairmen, Secretaries, Reviewer are avilable in this pdf.
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Xie, Jiaxiang. "Effect of matrix composition on properties of polyamide 66/polyamide 6I-6T composites with high content of continuous glass fiber for optimizing surface performance." e-Polymers 23, no. 1 (January 1, 2023). http://dx.doi.org/10.1515/epoly-2022-8111.
Повний текст джерелаАнотація:
Abstract To optimize the surface performance of the composites of polyamide 66 and continuous glass fiber (50/50, weight ratio), poly(hexamethylene isoftalamide-co-terephthalamide) (PA6I-6T) was introduced. The composites were prepared by a twin-screw extruder, and the effect of PA6I-6T on the thermal and mechanical properties, as well as surface appearance was investigated. The results showed that the crystallization temperature and the melting point of the composites decreased with increasing the amount of PA6I-6T. The Jeziorny method proved that the presence of PA6I-6T did not change the nucleation mode and the crystal growth of PA66 in the hybrid matrix, and the Mo method revealed that the crystallization rate of PA66 decreased first and then increased with the increase of the PA6I-6T content. The reduction in the “floating fiber” on the surface of the composites was attributed to the decrease of the crystallization rate of PA66 in the presence of PA6I-6T. It was shown that the composites with smooth surface had a large melt flow index. Moreover, the composites with high content of PA6I-6T had low heat deformation temperatures. The mechanical properties of the composites did not change significantly with the increase of the PA6I-6T content. Scanning electron microscope (SEM) images revealed that glass fiber was evenly distributed in the matrix and strongly oriented parallel to the injection direction.
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Jefferson-Loveday, Richard J. "Differential Equation-Based Specification of Turbulence Integral Length Scales for Cavity Flows." Journal of Engineering for Gas Turbines and Power 139, no. 6 (February 7, 2017). http://dx.doi.org/10.1115/1.4035602.
Повний текст джерелаАнотація:
A new modeling approach has been developed that explicitly accounts for expected turbulent eddy length scales in cavity zones. It uses a hybrid approach with Poisson and Hamilton–Jacobi differential equations. These are used to set turbulent length scales to sensible expected values. For complex rim-seal and shroud cavity designs, the method sets an expected length scale based on local cavity width which accurately accounts for the large-scale wakelike flow structures that have been observed in these zones. The method is used to generate length scale fields for three complex rim-seal geometries. Good convergence properties are found, and a smooth transition of length scale between zones is observed. The approach is integrated with the popular Menter shear stress transport (SST) Reynolds-averaged Navier–Stokes (RANS) turbulence model and reduces to the standard Menter model in the mainstream flow. For validation of the model, a transonic deep cavity simulation is performed. Overall, the Poisson–Hamilton–Jacobi model shows significant quantitative and qualitative improvement over the standard Menter and k–ε two-equation turbulence models. In some instances, it is comparable or more accurate than high-fidelity large eddy simulation (LES). In its current development, the approach has been extended through the use of an initial stage of length scale estimation using a Poisson equation. This essentially reduces the need for user objectivity. A key aspect of the approach is that the length scale is automatically set by the model. Notably, the current method is readily implementable in an unstructured, parallel processing computational framework.