To see the other types of publications on this topic, follow the link: CFD; Dynamics; Heat transfer.
Journal articles on the topic 'CFD; Dynamics; Heat transfer'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'CFD; Dynamics; Heat transfer.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Yu, Jiu Yang, Li Jun Liu, Wei Lin, Qian Liu, Wen Hao Yang, Si Hao Nie, and Yi Wen Chen. "Numerical Simulation and Field Synergy Analysis of Flow and Heat Transfer in a Vibratory Tube." Advanced Materials Research 516-517 (May 2012): 949–53. http://dx.doi.org/10.4028/www.scientific.net/amr.516-517.949.
Full textAbstract:
The present paper focuses on the analysis of transient heat transfer and flow in a vibratory tube. The characteristics of flow and heat transfer are investigated by dynamic mesh of CFD (computational fluid dynamics) software FLUENT, the velocity and temperature distributions in a vibration cycle are analyzed by field synergy theory. The results indicate that the vibration parameters have great effect on heat transfer, and the tube vibration leads to heat transfer enhancement or reduction. Moreover, the optimum heat transfer performance inside tubes is obtained in a half-cycle when time phase is 90°.
2
Giri, K. C. "Study of Thermal Performance of Closed Loop Pulsating Heat Pipe using Computational Fluid Dynamics." International Journal for Research in Applied Science and Engineering Technology 9, no. 9 (September 30, 2021): 1384–88. http://dx.doi.org/10.22214/ijraset.2021.38088.
Full textAbstract:
Abstract: Pulsating heat pipe is a heat transfer device which works on two principles that is phase transition and thermal conductivity which transfer heat effectively at different temperatures. Different factors affect the thermal performance of pulsating heat pipe. So, various researchers tried to enhance thermal conductivity by changing parameters such as working fluids, filling ratio, etc. Analysis of heat transfer characteristics of closed loop pulsating heat pipe (CLPHP) is to be carried out by using Computational Fluid Dynamics. The CLPHP is to be modelled on ANSYS Workbench, the flow of CLPHP is to be observed under specific boundary conditions by using ANSYS Fluent software. Acetone and Water are taken as the working fluid with 70% filling ratio at ambient temperature 30° C and the heat flux of 200 W is supplied at evaporator. Also, the analysis has been done to know the behaviour of PHPs under varying supply of heat flux at evaporator (inlet), the output heat flux is obtained at condenser (outlet) and find out how the heat flux is varying at different temperatures. CFD results shows the heat transfer characteristics observing the performance of CLPHP is a numerical manner. The obtained CFD results are compared with the experimental. The outputs of the simulations are plotted in graphs and outlines. Keywords: Closed Loop Pulsating Heat Pipe, CFD, Heat Transfer, ANSYS.
3
Wrobel, Luiz C., Maciej K. Ginalski, Andrzej J. Nowak, Derek B. Ingham, and Anna M. Fic. "An overview of recent applications of computational modelling in neonatology." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 368, no. 1920 (June 13, 2010): 2817–34. http://dx.doi.org/10.1098/rsta.2010.0052.
Full textAbstract:
This paper reviews some of our recent applications of computational fluid dynamics (CFD) to model heat and mass transfer problems in neonatology and investigates the major heat and mass-transfer mechanisms taking place in medical devices, such as incubators, radiant warmers and oxygen hoods. It is shown that CFD simulations are very flexible tools that can take into account all modes of heat transfer in assisting neonatal care and improving the design of medical devices.
4
Wichangarm, Mana, Anirut Matthujak, Thanarath Sriveerakul, Sedthawatt Sucharitpwatskul, and Sutthisak Phongthanapanich. "Simulation Study of LPG Cooking Burner." International Journal of Engineering & Technology 7, no. 3.7 (July 4, 2018): 142. http://dx.doi.org/10.14419/ijet.v7i3.7.16257.
Full textAbstract:
The objective of this paper is to numerically study the flow feature and combustion phenomena of an energy-saving cooking burner using three-dimensional computational fluid dynamics (CFD). Combustion temperatures were experimentally and numerically investigated in order to not only validate the CFD model, but also describe the combustion phenomena. From the temperature comparison, the CFD model was good agreement with the experiment, having the error of less than 5.86%. Based upon the insight from the CFD model, the high temperature of 1,286 K occurred at the middle of the burner. The high intensive vortex of the flow being enhanced the combustion intensity and the heat transfer coefficient is obvious observed near the burner head inside the ring. Therefore, it is concluded that the burner ring is the major part since it controls flame structure, high temperature region, intensive combustion region, heat loss and suitable flow feature. However, heat transfer to the vessel should be further clarified by the CFD model.
5
Yin, Zhi Ren, Li Jun Yang, and Run Ze Duan. "CFD Simulation of Heat Transfer of Pulsating Gas in a Pipe." Applied Mechanics and Materials 687-691 (November 2014): 623–26. http://dx.doi.org/10.4028/www.scientific.net/amm.687-691.623.
Full textAbstract:
Numerical Simulation of pulsating flow in a pulse combustor tailpipe was performed using computational fluid dynamics (CFD) method. The flow in the pipe was characterized by periodic pulsating. The influence of this pulsating includes incomplete flow development and high level of convective heat transfer rate, and both were considered and investigated by the CFD model. Compared with the steady flow condition, results showed that the heat transfer coefficient and Nusselt number were 2.35 times higher.
6
Wernik, Jacek, and Krzysztof J. Wołosz. "Study of Heat Transfer in Pneumatic Pulsator." Applied Mechanics and Materials 797 (November 2015): 320–26. http://dx.doi.org/10.4028/www.scientific.net/amm.797.320.
Full textAbstract:
The article presents selected results of research work aimed to rationalize and optimize the design of the pneumatic pulsator due to thermal conditions. Pneumatic pulsator is a device used in industry storing bulk and loose materials. It is attached to the silo, allowing their correct operation. The air friction against the inner wall of the pulsator causes the release of heat. In order to investigate the conditions of heat transfer, thermal calculations were made and then numerical simulations using Computational Fluid Dynamics (CFD) were conducted. Various fins options were examined. The objective was to maximize the heat flux discharged from the device. Temperature distribution on the surface of the fins designated by CFD corresponds to the distribution designated analytically. The results were confirmed by industrial tests. Numerical simulations mapping the heat exchange processes in a pneumatic pulsator have not yet been carried out.
7
Salcudean, Martha. "COMPUTATIONAL FLUID FLOW AND HEAT TRANSFER – AN ENGINEERING TOOL." Transactions of the Canadian Society for Mechanical Engineering 15, no. 2 (June 1991): 125–35. http://dx.doi.org/10.1139/tcsme-1991-0007.
Full textAbstract:
The purpose, method and potential of computational fluid dynamics are discussed. Examples of CFD and heat transfer applications to engineering problems are described. Some limitations related to discretization, convergence rate and turbulence modelling are illustrated through examples, and possible remedies arc discussed.
8
Virr, G. P., J. W. Chew, and J. Coupland. "Application of Computational Fluid Dynamics to Turbine Disk Cavities." Journal of Turbomachinery 116, no. 4 (October 1, 1994): 701–8. http://dx.doi.org/10.1115/1.2929463.
Full textAbstract:
A CFD code for the prediction of flow and heat transfer in rotating turbine disk cavities is described and its capabilities demonstrated through comparison with available experimental data. Application of the method to configurations typically found in aeroengine gas turbines is illustrated and discussed. The code employs boundary-fitted coordinates and uses the k–ε turbulence model with alternative near-wall treatments. The wall function approach and a one-equation near-wall model are compared and it is shown that there are particular limitations in the use of wall functions at low rotational Reynolds number. Validation of the code includes comparison with earlier CFD calculations and measurements of heat transfer, disk moment, and fluid velocities. It is concluded that, for this application CFD is a valuable design tool capable of predicting the flow at engine operating conditions, thereby offering the potential for reduced engine testing through enhanced understanding of the physical processes.
9
Liao, L., A. K. Athienitis, L. Candanedo, K. W. Park, Y. Poissant, and M. Collins. "Numerical and Experimental Study of Heat Transfer in a BIPV-Thermal System." Journal of Solar Energy Engineering 129, no. 4 (May 15, 2007): 423–30. http://dx.doi.org/10.1115/1.2770750.
Full textAbstract:
This paper presents a computational fluid dynamics (CFD) study of a building-integrated photovoltaic thermal (BIPV∕T) system, which generates both electricity and thermal energy. The heat transfer in the BIPV∕T system cavity is studied with a two-dimensional CFD model. The realizable k‐ε model is used to simulate the turbulent flow and convective heat transfer in the cavity, including buoyancy effect and long-wave radiation between boundary surfaces is also modeled. A particle image velocimetry (PIV) system is employed to study the fluid flow in the BIPV∕T cavity and provide partial validation for the CFD model. Average and local convective heat transfer coefficients are generated with the CFD model using measured temperature profile as boundary condition. Cavity temperature profiles are calculated and compared to the experimental data for different conditions and good agreement is obtained. Correlations of convective heat transfer coefficients are generated for the cavity surfaces; these coefficients are necessary for the design and analysis of BIPV∕T systems with lumped parameter models. Local heat transfer coefficients, such as those presented, are necessary for prediction of temperature distributions in BIPV panels.
10
Flamarz, Sherko. "Computational Study of Heat Transfer Behavior in Fluid-Solid Fluidized Beds." Sulaimani Journal for Engineering Sciences 7, no. 3 (December 30, 2020): 25–41. http://dx.doi.org/10.17656/sjes.10132.
Full textAbstract:
Heat transfer in fluid-solid fluidized beds is investigated using a combined of computational fluid dynamics (CFD) and discrete element method (DEM) approach, incorporated with a thermal model. The approach has taken into account almost all the mechanisms in heat transfer in fluidized beds. A comparison and validation of hydrodynamic and thermal data of fluidized bed obtained using CFD-DEM thermal approach with experimental and numerical results data in the literature is carried out. The simulations results reveal a good thermal steady state during the simulation time for calculating the thermal behaviors of fluidized beds like; the mean particle temperature, bed porosity, heat transfer coefficient and mean particle Reynolds number. The simulations results are showed a good agreement and consistency with the experimental and numerical data in the literatures. Thus, the integration of combined CFD-DEM with the thermal model is a step toward for the prediction, development the heat transfer efficiency in fluid-solid system, and the decrease of energy consumption of the industrial applications.
11
Chen, Long, and Binxin Wu. "Research Progress in Computational Fluid Dynamics Simulations of Membrane Distillation Processes: A Review." Membranes 11, no. 7 (July 7, 2021): 513. http://dx.doi.org/10.3390/membranes11070513.
Full textAbstract:
Membrane distillation (MD) can be used in drinking water treatment, such as seawater desalination, ultra-pure water production, chemical substances concentration, removal or recovery of volatile solutes in an aqueous solution, concentration of fruit juice or liquid food, and wastewater treatment. However, there is still much work to do to determine appropriate industrial implementation. MD processes refer to thermally driven transport of vapor through non-wetted porous hydrophobic membranes, which use the vapor pressure difference between the two sides of the membrane pores as the driving force. Recently, computational fluid dynamics (CFD) simulation has been widely used in MD process analysis, such as MD mechanism and characteristics analysis, membrane module development, preparing novel membranes, etc. A series of related research results have been achieved, including the solutions of temperature/concentration polarization and permeate flux enhancement. In this article, the research of CFD applications in MD progress is reviewed, including the applications of CFD in the mechanism and characteristics analysis of different MD structures, in the design and optimization of membrane modules, and in the preparation and characteristics analysis of novel membranes. The physical phenomena and geometric structures have been greatly simplified in most CFD simulations of MD processes, so there still is much work to do in this field in the future. A great deal of attention has been paid to the hydrodynamics and heat transfer in the channels of MD modules, as well as the optimization of these modules. However, the study of momentum transfer, heat, and mass transfer mechanisms in membrane pores is rarely involved. These projects should be combined with mass transfer, heat transfer and momentum transfer for more comprehensive and in-depth research. In most CFD simulations of MD processes, some physical phenomena, such as surface diffusion, which occur on the membrane surface and have an important guiding significance for the preparation of novel membranes to be further studied, are also ignored. As a result, although CFD simulation has been widely used in MD process modeling already, there are still some problems remaining, which should be studied in the future. It can be predicted that more complex mechanisms, such as permeable wall conditions, fouling dynamics, and multiple ionic component diffusion, will be included in the CFD modeling of MD processes. Furthermore, users’ developed routines for MD processes will also be incorporated into the existing commercial or open source CFD software packages.
12
Kumar, Ravi Shankar, and D. S. Chauhan. "A Review of CFD Analysis of Heat Exchanger for Laminar Flow." SMART MOVES JOURNAL IJOSCIENCE 7, no. 3 (March 26, 2021): 9–12. http://dx.doi.org/10.24113/ijoscience.v7i3.363.
Full textAbstract:
Helical coil heat exchangers, due to their maturity, are widely used in industrial applications such as the chemical and food industry, power generation, electronics, environmental technology, manufacturing industry, air conditioning, waste heat recovery, etc. on straight and cup heat exchangers. With its compact structure, larger heat transfer area and higher heat transfer capacity, etc., the twisted tap and classification of improvement techniques are presented in this paper. To present the dynamics, application, and advantages of CFD for computational fluids presented in this paper.
13
Walter, Christian, Sebastian Martens, Christian Zander, Carsten Mehring, and Ulrich Nieken. "Heat Transfer through Wire Cloth Micro Heat Exchanger." Energies 13, no. 14 (July 10, 2020): 3567. http://dx.doi.org/10.3390/en13143567.
Full textAbstract:
The main objective of this study is to calculate and determine design parameters for a novel wire cloth micro heat exchanger. Wire cloth micro heat exchangers offer a range of promising applications in the chemical industry, plastics technology, the recycling industry and energy technology. We derived correlations to calculate the heat transfer rate, pressure drop and temperature distributions through the woven structure in order to design wire cloth heat exchangers for different applications. Computational Fluid Dynamics (CFD) simulations have been carried out to determine correlations for the dimensionless Euler and Nusselt numbers. Based on these correlations, we have developed a simplified model in which the correlations can be used to calculate temperature distributions and heat exchanger performance. This allows a wire cloth micro heat exchanger to be virtually designed for different applications.
14
Koowattanasuchat, Pramote, Numpon Mahayotsanun, Sedthawatt Sucharitpwatskul, Sasawat Mahabunphachai, and Kuniaki Dohda. "Heat Transfer Enhancement by Shot Peening of Stainless Steel." Coatings 10, no. 6 (June 23, 2020): 584. http://dx.doi.org/10.3390/coatings10060584.
Full textAbstract:
In heat exchange applications, the heat transfer efficiency could be improved by surface modifications. Shot peening was one of the cost-effective methods to provide different surface roughness. The objectives of this study were (1) to investigate the influences of the surface roughness on the heat transfer performance and (2) to understand how the shot peening process parameters affect the surface roughness. The considered specimens were 316L stainless steel hollow tubes having smooth and rough surfaces. The computational fluid dynamics (CFD) simulation was used to observe the surface roughness effects. The CFD results showed that the convective heat transfer coefficients had linear relationships with the peak surface roughness (Rz). Finite element (FE) simulation was used to determine the effects of the shot peening process parameters. The FE results showed that the surface roughness was increased at higher sandblasting speeds and sand diameters.
15
Davidy, Alon. "CFD Simulation of Forced Recirculating Fired Heated Reboilers." Processes 8, no. 2 (January 22, 2020): 145. http://dx.doi.org/10.3390/pr8020145.
Full textAbstract:
An advanced algorithm has been developed in order to analyze the performance of re-boiling process of crude oil flowing inside reboilers tubes. The proposed model is composed from Heptane fire heater and a tube array. The heat flux produced from burner is transferred to the crude oil flowing inside the tube. The computational model is composed of two phases—Simulation of fire by using Fire Dynamics Simulator software (FDS) version 5.0 and then a nucleate boiling computation of the crude oil. FDS code is formulated based on CFD (Computational Fluid Dynamics) of fire heater. The thermo-physical properties (such as: thermal conductivity, heat capacity, surface tension, viscosity) of the crude oil were estimated by using empirical correlations. The thermal heat transfer to evaporating two-phase crude oil mixture occur by bubble generation at the wall (nucleate boiling) has been calculated by using Chen correlation. It has been assumed that the overall convective heat transfer coefficient is composed from the nucleate boiling convective coefficient and the forced turbulent convective coefficient. The former is calculated by Forster Zuber empirical equation. The latter is computed from the Dittus-Boelter relationship. In order to validate the nucleate boiling heat transfer coefficient, a comparison has been performed to nucleate boiling convective coefficient obtained by Mostinski equation. The relative error between the nucleate boiling convective heat-transfer coefficients is 10.5%. The FDS numerical solution has been carried out by using Large Eddy Simulation (LES) method. This work has been further extended to include also the structural integrity aspects of the reboiler metal pipe by using COMSOL Multiphysics software. It was found out, that the calculated stress is less than the ultimate tensile strength of the AISI 310 Steel alloy.
16
DENYS, SIEGFRIED, JAN G. PIETERS, and KOEN DEWETTINCK. "Computational Fluid Dynamics Analysis for Process Impact Assessment during Thermal Pasteurization of Intact Eggs." Journal of Food Protection 68, no. 2 (February 1, 2005): 366–74. http://dx.doi.org/10.4315/0362-028x-68.2.366.
Full textAbstract:
Transient temperature and albumen velocity profiles during thermal pasteurization of intact eggs were studied using a commercial computational fluid dynamics (CFD) package. Simulated temperature profiles were in close agreement with experimental data for eggs of different sizes. Convective heat transfer only occurred in the egg white fraction, and conductive heat transfer only occurred in the yolk. For process assessment, a generally accepted kinetic inactivation model for Salmonella Enteritidis was incorporated into the CFD analysis. Minimum process times and temperatures needed to provide equivalent pasteurization at 5-log reductions of the target microorganism were obtained on a theoretical basis. The combination of CFD analysis and inactivation kinetics can be very useful for assessing pasteurization of intact eggs and can enable processors to gain a better understanding of these processes and to establish process conditions for consumer-safe eggs.
17
Zamora, Blas, Antonio S. Kaiser, and Pedro G. Vicente. "Improvement in Learning on Fluid Mechanics and Heat Transfer Courses Using Computational Fluid Dynamics." International Journal of Mechanical Engineering Education 38, no. 2 (April 2010): 147–66. http://dx.doi.org/10.7227/ijmee.38.2.6.
Full textAbstract:
This paper is concerned with the teaching of fluid mechanics and heat transfer on courses for the industrial engineer degree at the Polytechnic University of Cartagena (Spain). In order to improve the engineering education, a pedagogical method that involves project-based learning, using computational fluid dynamics (CFD), was applied. The project-based learning works well for mechanical engineering education, since it prepares students for their later professional training. The courses combined applied and advanced concepts of fluid mechanics with the basic numerical aspects of CFD, including validation of the results obtained. In this approach, the physical understanding of practical problems of fluid mechanics and heat transfer played an important role. Satisfactory numerical results were obtained by using both Phoenics and Fluent finite-volume codes. Some cases were solved using the well known Matlab software. Comparisons were made between the results obtained by analytical solutions (if any) with those reached by CFD general-purpose codes and with those obtained by Matlab. This system provides engineering students with a solid comprehension of several aspects of thermal and fluids engineering.
18
Baburic, Mario, Alexandre Raulot, and Neven Duic. "Implementation of discrete transfer radiation method into swift computational fluid dynamics code." Thermal Science 8, no. 1 (2004): 19–28. http://dx.doi.org/10.2298/tsci0401019b.
Full textAbstract:
The Computational Fluid Dynamics (CFD) has developed into a powerful tool widely used in science, technology and industrial design applications, when ever fluid flow, heat transfer, combustion, or other complicated physical processes, are involved. During decades of development of CFD codes scientists were writing their own codes, that had to include not only the model of processes that were of interest, but also a whole spectrum of necessary CFD procedures, numerical techniques, pre-processing and post-processing. That has arrested much of the scientist effort in work that has been copied many times over, and was not actually producing the added value. The arrival of commercial CFD codes brought relief to many engineers that could now use the user-function approach for mod el ling purposes, en trusting the application to do the rest of the work. This pa per shows the implementation of Discrete Transfer Radiation Method into AVL?s commercial CFD code SWIFT with the help of user defined functions. Few standard verification test cases were per formed first, and in order to check the implementation of the radiation method it self, where the comparisons with available analytic solution could be performed. After wards, the validation was done by simulating the combustion in the experimental furnace at IJmuiden (Netherlands), for which the experimental measurements were available. The importance of radiation prediction in such real-size furnaces is proved again to be substantial, where radiation itself takes the major fraction of over all heat transfer. The oil-combustion model used in simulations was the semi-empirical one that has been developed at the Power Engineering Department, and which is suit able for a wide range of typical oil flames.
19
Toth Pal, Zsolt, Ya Fan Zhang, Ilja Belov, Hans Peter Nee, and Mietek Bakowski. "Investigation of Pressure Dependent Thermal Contact Resistance between Silver Metallized SiC Chip and DBC Substrate." Materials Science Forum 821-823 (June 2015): 452–55. http://dx.doi.org/10.4028/www.scientific.net/msf.821-823.452.
Full textAbstract:
– Thermal contact resistances between a silver metallized SiC chip and a direct bonded copper (DBC) substrate have been measured in a heat transfer experiment. A novel experimental method to separate thermal contact resistances in multilayer heat transfer path has been demonstrated. The experimental results have been compared with analytical calculations and also with 3D computational fluid dynamics (CFD) simulation results. A simplified CFD model of the experimental setup has been validated. The results show significant pressure dependence of the thermal contact resistance but also a pressure independent part.
20
Konopacki, Maciej, Marian Kordas, Karol Fijałkowski, and Rafał Rakoczy. "Computational Fluid Dynamics and Experimental Studies of a New Mixing Element in a Static Mixer as a Heat Exchanger." Chemical and Process Engineering 36, no. 1 (March 1, 2015): 59–72. http://dx.doi.org/10.1515/cpe-2015-0005.
Full textAbstract:
Abstract The main aim of this work is to study the thermal efficiency of a new type of a static mixer and to analyse the flow and temperature patterns and heat transfer efficiency. The measurements were carried out for the static mixer equipped with a new mixing insert. The heat transfer enhancement was determined by measuring the temperature profiles on each side of the heating pipe as well as the temperature field inside the static mixer. All experiments were carried out with varying operating parameters for four liquids: water, glycerol, transformer oil and an aqueous solution of molasses. Numerical CFD simulations were carried out using the two-equation turbulence k-ω model, provided by ANSYS Workbench 14.5 software. The proposed CFD model was validated by comparing the predicted numerical results against experimental thermal database obtained from the investigations. Local and global convective heat transfer coefficients and Nusselt numbers were detrmined. The relationship between heat transfer process and hydrodynamics in the static mixer was also presented. Moreover, a comparison of the thermal performance between the tested static mixer and a conventional empty tube was carried out. The relative enhancement of heat transfer was characterised by the rate of relative heat transfer intensification.
21
Samad, Abdallah, Gitsuzo B. S. Tagawa, François Morency, and Christophe Volat. "Predicting Rotor Heat Transfer Using the Viscous Blade Element Momentum Theory and Unsteady Vortex Lattice Method." Aerospace 7, no. 7 (July 3, 2020): 90. http://dx.doi.org/10.3390/aerospace7070090.
Full textAbstract:
Calculating the unsteady convective heat transfer on helicopter blades is the first step in the prediction of ice accretion and the design of ice-protection systems. Simulations using Computational Fluid Dynamics (CFD) successfully model the complex aerodynamics of rotors as well as the heat transfer on blade surfaces, but for a conceptual design, faster calculation methods may be favorable. In the recent literature, classical methods such as the blade element momentum theory (BEMT) and the unsteady vortex lattice method (UVLM) were used to produce higher fidelity aerodynamic results by coupling them to viscous CFD databases. The novelty of this research originates from the introduction of an added layer of the coupling technique to predict rotor blade heat transfer using the BEMT and UVLM. The new approach implements the viscous coupling of the two methods from one hand and introduces a link to a new airfoil CFD-determined heat transfer correlation. This way, the convective heat transfer on ice-clean rotor blades is estimated while benefiting from the viscous extension of the BEMT and UVLM. The CFD heat transfer prediction is verified using existing correlations for a flat plate test case. Thrust predictions by the implemented UVLM and BEMT agree within 2% and 80% compared to experimental data. Tip vortex locations by the UVLM are predicted within 90% but fail in extreme ground effect. The end results present as an estimate of the heat transfer for a typical lightweight helicopter tail rotor for four test cases in hover, ground effect, axial, and forward flight.
22
Drikakis, Dimitris, Michael Frank, and Gavin Tabor. "Multiscale Computational Fluid Dynamics." Energies 12, no. 17 (August 25, 2019): 3272. http://dx.doi.org/10.3390/en12173272.
Full textAbstract:
Computational Fluid Dynamics (CFD) has numerous applications in the field of energy research, in modelling the basic physics of combustion, multiphase flow and heat transfer; and in the simulation of mechanical devices such as turbines, wind wave and tidal devices, and other devices for energy generation. With the constant increase in available computing power, the fidelity and accuracy of CFD simulations have constantly improved, and the technique is now an integral part of research and development. In the past few years, the development of multiscale methods has emerged as a topic of intensive research. The variable scales may be associated with scales of turbulence, or other physical processes which operate across a range of different scales, and often lead to spatial and temporal scales crossing the boundaries of continuum and molecular mechanics. In this paper, we present a short review of multiscale CFD frameworks with potential applications to energy problems.
23
Renze, Peter, and Kevin Akermann. "Simulation of Conjugate Heat Transfer in Thermal Processes with Open Source CFD." ChemEngineering 3, no. 2 (June 6, 2019): 59. http://dx.doi.org/10.3390/chemengineering3020059.
Full textAbstract:
A verification and validation study was performed using the open source computational fluid dynamics software package OpenFOAM version 6-dev for conjugate heat transfer problems. The test cases had a growing complexity starting from a simple steady state problem over unsteady heat transfer to more realistic engineering applications. First, a fin effectiveness study was performed. Then, the external convection at pipes and internal pipe heat transfer were investigated. The validity of the techniques was shown for each test case by comparing the simulation results with experimental and analytic data available in the literature. Finally, a simplified shell-and-tube heat exchanger was simulated to demonstrate how these methods can be applied to plant scale engineering problems.
24
Wankhede, Uday, and Ram Sonolikar. "Experimental analysis and computational fluid dynamics simulations for heat transfer in sound assisted fluidized bed of fine powders." Thermal Science 21, no. 5 (2017): 1953–63. http://dx.doi.org/10.2298/tsci150208124w.
Full textAbstract:
Fine powders in the size range of 20-200 ?m are widely used in industries for fluid bed operations and are ideal for gas-solid reactions because of their large external surface areas and favorable heat transfer rates. The fine powders have very poor flow characteristics. Most of the earlier research work in heat transfer in bubbling fluidized beds is focused on coarse grained Geldart B and D particles. Acoustic energy of sufficient intensity and sound pressure level improved the quality of fluidization of fine powders. The objective of this investigation is experimental analysis and CFD simulations for heat transfer in a fluidized bed of fine powders at different acoustic conditions. The Eulerian approach has been identified as an efficient method for the numerical simulation of fluidized beds. The experimental and CFD results are in good agreement with each other.
25
Stanisic, Stevan, Milica Jevtic, Bhaba Das, and Zoran Radakovic. "Fem CFD analysis of air flow in kiosk substation with the oil immersed distribution transformer." Facta universitatis - series: Electronics and Energetics 31, no. 3 (2018): 411–23. http://dx.doi.org/10.2298/fuee1803411s.
Full textAbstract:
In practice of loading of oil-immersed distribution transformers, there is a need to have lumped thermal model, requiring no big computational resources and computational time. One such model is presented in international transformer loading guide (IEC 60076-7), where heat transfer inside the transformer is modeled. In case of indoor transformer operation, this model does not consider transient thermal phenomena in the room. We developed a lumped model that includes heat transfer in the transformer room. In scope of the research, we also built FEM CFD (finite element method, computational fluid dynamics) model of air flow and heat transfer. The purpose of FEM CFD was to make a better insight into air flow, i.e. to study the simplifications introduced in lumped model and suggest potential improvements. This paper presents results achieved with FEM CFD. The considered case was the transformer with natural oil and natural air flow (ONAN).
26
Sass, Ádám, Alex Kummer, Zsolt Ulbert, and Attila Egedy. "Failure Analysis of Heat Exchangers with a Valid CFD Simulation." Periodica Polytechnica Chemical Engineering 65, no. 4 (August 26, 2021): 536–49. http://dx.doi.org/10.3311/ppch.17095.
Full textAbstract:
Energy efficiency, safety and stable operation of units are the most crucial aspects in every industrial process. In this study, Computational Fluid Dynamics (CFD) simulations were used to study heat transfer in a laboratory-sized tubular heat exchanger. A partly 2D axisymmetric and mainly 3D model of the heat exchanger was created and validated with several simulation in different operating points of heating capacity and volume flow. The results of the simulations were compared to experimental data to validate the model. The inlet and outlet temperatures were measured with Pt100 temperature probes, and the surface temperatures were measured with an infrared camera. The heat transfer coefficient was determined based on the surface measurements The validated model was applied for the investigation of performance losses of heat exchanger due to fouling caused by particle deposits along the tube which caused reduced heat transfer surface or performance and a failure of heating wire which caused reduced heating performance, hence altered heat and flow characteristics through the equipment. The results provide useful information not only in the design processes but the operational lifetime as well.
27
Robinson, K., M. Wilson, M. J. Leathard, and J. G. Hawley. "Computational modelling of convective heat transfer in a simulated engine cooling gallery." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 221, no. 9 (September 1, 2007): 1147–57. http://dx.doi.org/10.1243/09544070jauto450.
Full textAbstract:
Experimental data from internal combustion (IC) engines suggests that the use of proprietary computational fluid dynamics (CFD) codes for the prediction of coolant-side heat transfer within IC engine coolant jackets often results in underprediction of the convective heat transfer coefficient. An experimental and computational study, based on a coolant gallery simulator rig designed specifically to reproduce realistic IC engine operating conditions, has been conducted to explore this issue. It is shown that the standard ‘wall function’ approach normally used in CFD models to model near-wall conditions does not adequately represent some features of the flow that are relevant in convective heat transfer. Alternative modelling approaches are explored to account for these shortcomings and an empirical approach is shown to be successful; however, the methodology is not easily transferable to other situations.
28
Bhandarkar, A., Malsur Dharavath, M. S. R. Chandra Murty, P. Manna, and Debasis Chakraborty. "A Novel CFD Method to Estimate Heat Transfer Coefficient for High Speed Flows." Defence Science Journal 66, no. 3 (April 25, 2016): 203. http://dx.doi.org/10.14429/dsj.66.8873.
Full textAbstract:
<p>Accurate prediction of surface temperature of high speed aerospace vehicle is very necessary for the selection of material and determination of wall thickness. For aerothermal characterisation of any high speed vehicle in its full trajectory, it requires number of detailed computational fluid dynamics (CFD) calculations with different isothermal calculations. From the detailed CFD calculations for different flow conditions and geometries, it is observed that heat transfer coefficients scale with the difference of adiabatic wall temperature and skin temperature. A simple ‘isothermal method’, is proposed to calculate heat flux data with only two CFD simulations one on adiabatic condition and other on isothermal condition. The proposed methodology is validated for number of high speed test cases involving external aerodynamic heating as well as high speed combusting flow. The computed heat fluxes and surface temperatures matches well with experimental and flight measured values.</p>
29
Owolabi, Oluwasegun Biodun, Lawrence Opeyemi Osoba, and Samson Oluropo Adeosun. "THERMAL AND COMPUTATIONAL FLUID DYNAMICS ANALYSIS OF AN OIL FIRED CRUCIBLE FURNACE DURING SECONDARY ALUMINUM SMELTING." Journal of Production Engineering 23, no. 2 (December 30, 2020): 21–27. http://dx.doi.org/10.24867/jpe-2020-02-021.
Full textAbstract:
Thermal and computational fluid dynamics (CFD) analysis were explore with knowledge based software such as Solid Works and ANSYS workbench 14.0 for modeling and simulation of an Oil fired crucible furnace used for aluminum secondary smelting. Thermal analysis gives the maximum heat flux and directional heat flux as 8.7596W/mm2 and 8.0349 W/mm2 respectively. CFD simulation shows that the effect of the process parameter on the furnace components is as a result of furnace factors. In brevity theoretical calculations of thermal stress up in the furnace and heat transfer to crucible conform to the modelled results.
30
Högblom, Olle, and Ronnie Andersson. "Multiphysics CFD Simulation for Design and Analysis of Thermoelectric Power Generation." Energies 13, no. 17 (August 22, 2020): 4344. http://dx.doi.org/10.3390/en13174344.
Full textAbstract:
The multiphysics simulation methodology presented in this paper permits extension of computational fluid dynamics (CFD) simulations to account for electric power generation and its effect on the energy transport, the Seebeck voltage, the electrical currents in thermoelectric systems. The energy transport through Fourier, Peltier, Thomson and Joule mechanisms as a function of temperature and electrical current, and the electrical connection between thermoelectric modules, is modeled using subgrid CFD models which make the approach computational efficient and generic. This also provides a solution to the scale separation problem that arise in CFD analysis of thermoelectric heat exchangers and allows the thermoelectric models to be fully coupled with the energy transport in the CFD analysis. Model validation includes measurement of the relevant fluid dynamic properties (pressure and temperature distribution) and electric properties (current and voltage) for a turbulent flow inside a thermoelectric heat exchanger designed for automotive applications. Predictions of pressure and temperature drop in the system are accurate and the error in predicted current and voltage is less than 1.5% at all exhaust gas flow rates and temperatures studied which is considered very good. Simulation results confirm high computational efficiency and stable simulations with low increase in computational time compared to standard CFD heat-transfer simulations. Analysis of the results also reveals that even at the lowest heat transfer rate studied it is required to use a full two way coupling in the energy transport to accurately predict the electric power generation.
31
Lindqvist, Karl, Zachary Wilson, Erling Næss, and Nikolaos Sahinidis. "A Machine Learning Approach to Correlation Development Applied to Fin-Tube Bundle Heat Exchangers." Energies 11, no. 12 (December 10, 2018): 3450. http://dx.doi.org/10.3390/en11123450.
Full textAbstract:
Heat exchanger designers need reliable thermal-hydraulic correlations to optimize heat exchanger designs. This work combines an adaptive sampling method with a Computational Fluid Dynamics (CFD) simulator to obtain increased accuracy and validity range of heat transfer and pressure drop predictions using a limited number of data points. Correlation efficacy was evaluated based on a steam generator case study. The sensitivity to the design parameters was analyzed in detail. The RMSE (root mean square error) of the developed correlations were reduced, through CFD sampling, from 28% to 15% for pressure drop, and from 33% to 25% heat transfer, compared to regression on experimental data only. The best reference correlations have RMSE values of 43% and 33% on pressure drop and heat transfer, respectively, on an independent validation set. Indeed, a radically different fin-tube geometry was suggested for the case study, compared to results using the Escoa correlations.The developed correlations show good to excellent agreement with trends in the CFD model. The quantitative error of predicted heat transfer and pressure drop coefficients at the case study optimum, however, was as large as those of the Escoa correlations. More data are likely needed to improve accuracy for compact heat exchanger designs further.
32
Xu, Shi Long, Yan Shi, and Shou Cheng Li. "Heat Transfer and Thermal Load Analysis of Exhaust Manifold." Applied Mechanics and Materials 226-228 (November 2012): 2240–44. http://dx.doi.org/10.4028/www.scientific.net/amm.226-228.2240.
Full textAbstract:
With the appearance of high temperature resistance alloy steel and the requirement of light weight for vehicles, more and more exhaust manifolds are made from newly developed alloy steel. The changing of material directly affects the design and manufacturing process. To estimate the thermal load of the tight-coupled exhaust manifold, the joint analysis methods of CFD and FEM are put forward to predict the temperature distribution, thermal stress and deformation. Using Computational Fluid Dynamics (CFD) method, gas temperature and convective heat transfer coefficient, adjoining the inside and outside surfaces of the exhaust manifold, are estimated firstly in this paper. Then these results are mapped to the finite element mesh of exhaust manifold, which are created for the heat transfer analysis. At last, thermal stress and thermal deformation analysis are presented by taking nonlinear material properties into account, which provide some reference to evaluate the cooling capacity and structure design of exhaust manifold.
33
BULLOUGH, W. A., D. J. ELLAM, and R. J. ATKIN. "PRE-PROTOTYPE DESIGN OF ER/MR DEVICES USING COMPUTATIONAL FLUID DYNAMICS: UNSTEADY FLOW." International Journal of Modern Physics B 19, no. 07n09 (April 10, 2005): 1605–11. http://dx.doi.org/10.1142/s0217979205030657.
Full textAbstract:
A feasibility investigation into modelling ER/MR devices in transient operation using CFD is summarised. This particular study is one part of a project which has previously included examining 1D and 2D steady state flow, heat transfer, and field distributions using CFD. Though developed piecewise, these various CFD approaches can be integrated to allow a full pre-prototype assessment programme for almost any device conceived, in any mode or sequence of operation. Solutions which include translating boundary motion and inertial boundaries are introduced. In order to verify the CFD results, some new experimental works were carried out on a hydrodynamic bearing and clutch apparatus.
34
Singh, Sanskar, Vandana Singh, and Kajol Kumari. "Heat Transfer Analysis During Quenching of Plate Roller in Quenching Machine Using CFD." SMART MOVES JOURNAL IJOSCIENCE 5, no. 9 (October 12, 2019): 31–37. http://dx.doi.org/10.24113/ijo-science.v5i6.240.
Full textAbstract:
A computational fluid dynamics analysis of steel plate using volume of fluid multiphase model moving at different velocity i.e. 0.1 to 1 m/sec with 0.1 m/sec interval. From the above concluding points it has been observed that heat flux increased for the steel plate moving at 0.1 m/sec. During quenching process the surface heat transfer coefficient increases at first. And when plate surface temperature is nearly 420 oC, surface heat transfer coefficients reach the maximum value of about 15000 W/(m2K). And then, The calculated heat transfer coefficients are applied to analyze plate temperature field of different thicknesses, and the difference between the calculated and measured temperature is less than 35 %.
35
Payami, Seyed Pezhman, Masud Behnia, Barry Dixon, John Santamaria, and Mehrdad Behnia. "Numerical Simulation of Flow, Heat and Moisture Transfer in Heat and Moisture Exchanger (HME) Devices." Applied Mechanics and Materials 553 (May 2014): 121–29. http://dx.doi.org/10.4028/www.scientific.net/amm.553.121.
Full textAbstract:
Heat and Moisture Exchanger (HME) is a simple solution to the problems of warming and humidification of inspired gases during ventilator treatment. The device acts as an “artificial” nose or passive humidifier, added to the breathing circuit to retain and exchange heat and moisture between inspiration and expiration. The HME traps expiratory heat and moisture from patient’s exhaled breath in a porous medium and returns a portion of them through the subsequent inspiratory cycle. The aim of our paper is to develop a computational fluid dynamics (CFD) model of an HME device commonly used in anaesthesia and intensive care. The CFD results allow a better understanding of flow behaviour leading to the design of more efficient devices. The CFD model solves the gas flow, heat and mass transfer equations in a DAR Hygrobac S (Mallinckrodt DAR, Mirandola, Italy). The temperature, absolute humidity and pressure fields are obtained during expiratory phase to evaluate heat and moisture conserving efficiencies and air flow resistance. The effect of flow rate as one of the major parameters in ventilator setting on temperature, humidity and pressure drop is determined. Inside the HME device, areas of recirculation are observed. As the flow rate increases the output temperature and absolute humidity go up causing a reduction in heat and moisture conserving capacities. Comparison of the CFD results with previously obtained experimental data shows a satisfactory agreement.
36
Onan, Cenk, Derya Burcu Ozkan, and Serkan Erdem. "CFD and Experimental Analysis of a Falling Film outside Smooth and Helically Grooved Tubes." Advances in Mechanical Engineering 6 (January 1, 2014): 915034. http://dx.doi.org/10.1155/2014/915034.
Full textAbstract:
Simultaneous heat and mass transfer are investigated in a falling film outside grooved and smooth tubes. A numerical analysis of the helically trapezoidal-grooved and reference smooth tube was performed in the computational fluid dynamics program “Ansys Fluent 14.” The three-dimensional model drawings in the x, y, and z coordinates are used, and the effects of the falling film outside the helically grooved tube on the surface temperature and surface heat transfer coefficient are determined. The average surface temperature, heat transfer coefficient, and Nu values are determined experimentally for a constant heat flux. An uncertainty analysis and Nu correlation for the grooved tube are also provided in this study. The Reynolds number varied between 50 and 350 for the falling film and between 1500 and 3500 for air. Using a computational fluid dynamics (CFD) analysis for the reference smooth tube, the experimental results are validated within 2–12% difference. The experimental results are also within 6–13% of the grooved tubes.
37
La Cerva, Mariagiorgia, Andrea Cipollina, Michele Ciofalo, Mohammed Albeirutty, Nedim Turkmen, Salah Bouguecha, and Giorgio Micale. "CFD Investigation of Spacer-Filled Channels for Membrane Distillation." Membranes 9, no. 8 (July 25, 2019): 91. http://dx.doi.org/10.3390/membranes9080091.
Full textAbstract:
The membrane distillation (MD) process for water desalination is affected by temperature polarization, which reduces the driving force and the efficiency of the process. To counteract this phenomenon, spacer-filled channels are used, which enhance mixing and heat transfer but also cause higher pressure drops. Therefore, in the design of MD modules, the choice of the spacer is crucial for process efficiency. In the present work, different overlapped spacers are investigated by computational fluid dynamics (CFD) and results are compared with experiments carried out with thermochromic liquid crystals (TLC). Results are reported for different flow attack angles and for Reynolds numbers (Re) ranging from ~200 to ~800. A good qualitative agreement between simulations and experiments can be observed for the areal distribution of the normalized heat transfer coefficient. Trends of the average heat transfer coefficient are reported as functions of Re for the geometries investigated, thus providing the basis for CFD-based correlations to be used in higher-scale process models.
38
Chen, Hung Chien, Tzu Chen Hung, and Yi Feng Chen. "Numerical Analysis of Heat Transfer in the Concentric Heat Exchanger." Applied Mechanics and Materials 275-277 (January 2013): 572–75. http://dx.doi.org/10.4028/www.scientific.net/amm.275-277.572.
Full textAbstract:
The computational fluid dynamics (CFD) software is used to compute three-dimensional concentric heat exchanger in this research. In order to reduce the burden of the computational time, the concentric heat exchanger is simplified sector of 5° for the regular arrangement of internal shape. The working fluids for hot flow and cold flow are helium and molten salt individually. The arrangements for hot and cold flow paths within a heat exchanger is opposite. This study is mainly focused on the distribution of field for the two layers of concentric heat exchanger. The width of the flow channel as well as the length, pitch, thickness and angle of fin have been changing to analyze the effectiveness-NTU method. The results showed that the best heat transfer of fin thickness, angle, space, length, and flow channel are under 5mm, 5°, 8mm, 44mm, and 12mm, respectively.
39
Li, Yong An, Ya Nan Gao, Ming Wang, and Xue Lai Liu. "Study on Coupled Conduction and Convection Heat Transfer Based on Internal Heat Source." Applied Mechanics and Materials 90-93 (September 2011): 3001–4. http://dx.doi.org/10.4028/www.scientific.net/amm.90-93.3001.
Full textAbstract:
A computational fluid dynamics (CFD) model is proposed to simulate numerically conjugated heat transfer process of fluid washing out solid with evenly internal heat source in the pipe. Temperature field and velocity field inside the pipe and outside solid are gained by calculation. Based on numerical simulation, the varying regularity of Nusselt number between fluid and solid wall surface is obtained and analyzed. The results show that there are two symmetrical vortexes in the back of solid. The Nusselt number and heat exchange rate dramatically decrease with increasing horizontal distance of top and bottom of solid.
40
Pianko-Oprych, Paulina, and Zdzisław Jaworski. "3D CFD fluid flow and thermal analyses of a new design of plate heat exchanger." Polish Journal of Chemical Technology 19, no. 1 (March 28, 2017): 17–26. http://dx.doi.org/10.1515/pjct-2017-0003.
Full textAbstract:
Abstract The paper presents a Computational Fluid Dynamics (CFD) numerical study for a new design of a plate heat exchanger with two different flow patterns. The impact of geometric characteristics of the two studied geometries of exchanger plates on the intensification process of heat transfer was considered. The velocity, temperature and pressure distributions along the heat exchanger were examined. The CFD results were validated against experimental data and a good agreement was achieved. The results revealed that geometrical arrangement of the plates strongly influence the fluid flow. An increase in the Reynolds number led to lowering the friction factor value and increasing the pressure drop. The configuration II of the plate heat exchanger resulted in lower outlet hot fluid temperature in comparison with the configuration I, which means improvement of heat transfer.
41
Krawczyk, Piotr, and Krzysztof Badyda. "Two-dimensional CFD modeling of the heat and mass transfer process during sewage sludge drying in a solar dryer." Archives of Thermodynamics 32, no. 4 (December 1, 2011): 3–16. http://dx.doi.org/10.2478/v10173-011-0028-y.
Full textAbstract:
Two-dimensional CFD modeling of the heat and mass transfer process during sewage sludge drying in a solar dryer The paper presents key assumptions of the mathematical model which describes heat and mass transfer phenomena in a solar sewage drying process, as well as techniques used for solving this model with the Fluent computational fluid dynamics (CFD) software. Special attention was paid to implementation of boundary conditions on the sludge surface, which is a physical boundary between the gaseous phase - air, and solid phase - dried matter. Those conditions allow to model heat and mass transfer between the media during first and second drying stages. Selection of the computational geometry is also discussed - it is a fragment of the entire drying facility. Selected modelling results are presented in the final part of the paper.
42
Chatterjee, Sushovan, Subhasish Das, and Neelam Kumar Sarma. "Evaluation of bend curvature of superheater tube using CFD analysis." World Journal of Engineering 18, no. 3 (February 1, 2021): 497–504. http://dx.doi.org/10.1108/wje-06-2020-0219.
Full textAbstract:
Purpose The heat transfer within a heat exchanger is highly influenced by geometry of the components especially those with hollow structures like tubes. This paper aims to intend toward the study of efficient and optimized heat transfer in the bends of superheater tubes, with different curvature ratio at constant Reynolds Number. Design/methodology/approach The effect of changing curvature ratio on enthalpy of the fluid passing through the superheater tubes for multi-pass system has been studied with the aid of computational fluid dynamics (CFD) using ANSYS 14.0. Initially a superheater tube with two pass system has been examined with different curvature ratios of 1.425, 1.56, 1.71, 1.85 and 1.99. An industry specified curvature ratio of 1.71 with two pass is investigated, and a comparative assessment has been carried out. This is intended toward obtaining an optimized radius of curvature of the bend for enhancement of heat transfer. Findings The results obtained from software simulation revealed that the curvature ratio of 1.85 provides maximum heat transfer to the fluid flowing through the tube with two pass. This result has been found to be consistent with higher number of passes as well. The effect of secondary flow in bends of curvature has also been illustrated in the present work. Research limitations/implications The study of heat transfer in thermodynamic systems is a never-ending process and has to be continued for the upliftment of power plant performances. This study has been conducted on steady flow behavior of the fluid which may be upgraded by carrying out the same in transient mode. The impact of different curvature ratios on some important parameters such as heat transfer coefficients will certainly upgrade the value of research. Originality/value This computational study provided comprehensive information on fluid flow behavior and its effect on heat transfer in bends of curvature of superheater tubes inside the boiler. It also provides information on optimized bend of curvature for efficient heat transfer process.
43
White, John. "A CFD Simulation on How the Different Sizes of Silica Gel Will Affect the Adsorption Performance of Silica Gel." Modelling and Simulation in Engineering 2012 (2012): 1–12. http://dx.doi.org/10.1155/2012/651434.
Full textAbstract:
The application of computational fluid dynamics (CFD) in the area of porous media and adsorption cooling system is becoming more practical due to the significant improvement in computer power. The results from previous studies have shown that CFD can be useful tool for predicting the water vapour flow pattern, temperature, heat transfer, flow velocity, and adsorption rate. This paper investigates the effect of silica gel granular size on the water adsorption rate using computational fluid dynamics.
44
Abdulmajeed, Basma Abbas, and Hawraa Riyadh Jawad. "CFD Application on Shell and Double Concentric Tube Heat Exchanger." Journal of Engineering 25, no. 2 (January 31, 2019): 136–50. http://dx.doi.org/10.31026/j.eng.2019.02.09.
Full textAbstract:
This work is concerned with the design and performance evaluation of a shell and double concentric tubes heat exchanger using Solid Works and ANSY (Computational Fluid Dynamics).
Computational fluid dynamics technique which is a computer-based analysis is used to simulate the heat exchanger involving fluid flow, heat transfer. CFD resolve the entire heat exchanger in discrete elements to find: (1) the temperature gradients, (2) pressure distribution, and (3) velocity vectors. The RNG k-ε model of turbulence is used to determining the accurate results from CFD.
The heat exchanger design for this work consisted of a shell and eight double concentric tubes. The number of inlets are three and that of outlets are also three for all the fluids that pass through the heat exchanger.
A comparison was made for the numerical and experimental results and it was found that the percentage error for the hot oil outlet temperature was (6.8%) and the percentage error was (- 21%) for cold water outlet temperature.
45
Konchada, Pavan Kumar, Vinay Pv, and Varaprasad Bhemuni. "Statistical analysis of entropy generation in longitudinally finned tube heat exchanger with shell side nanofluid by a single phase approach." Archives of Thermodynamics 37, no. 2 (June 1, 2016): 3–22. http://dx.doi.org/10.1515/aoter-2016-0010.
Full textAbstract:
AbstractThe presence of nanoparticles in heat exchangers ascertained increment in heat transfer. The present work focuses on heat transfer in a longitudinal finned tube heat exchanger. Experimentation is done on longitudinal finned tube heat exchanger with pure water as working fluid and the outcome is compared numerically using computational fluid dynamics (CFD) package based on finite volume method for different flow rates. Further 0.8% volume fraction of aluminum oxide (Al2O3) nanofluid is considered on shell side. The simulated nanofluid analysis has been carried out using single phase approach in CFD by updating the user-defined functions and expressions with thermophysical properties of the selected nanofluid. These results are thereafter compared against the results obtained for pure water as shell side fluid. Entropy generated due to heat transfer and fluid flow is calculated for the nanofluid. Analysis of entropy generation is carried out using the Taguchi technique. Analysis of variance (ANOVA) results show that the inlet temperature on shell side has more pronounced effect on entropy generation.
46
Chai, Almon. "Simulations on Modified Burner Configuration Using CFD." Applied Mechanics and Materials 465-466 (December 2013): 510–14. http://dx.doi.org/10.4028/www.scientific.net/amm.465-466.510.
Full textAbstract:
The findings of computational fluid dynamics simulation results performed on an industrial roller-kiln are presented here. The modification was emphasized on the temperature distribution during the drying process of ceramic-tiles. A computational fluid-dynamics solver was used in the modeling and simulation of the temperature distribution. Boundary conditions for the burners were setup with different temperature outputs for the burners, indicated as initial settings and modified burner configuration settings. The simulation results were shown in contour-plots, demonstrating consistent heat circulation throughout the drying chamber near the burner regions. The comparison of initial and secondary simulation results also demonstrated consistent temperature distribution near the ceramic-tiles region within the drying chamber. This consistency in heat transfer has proven that similar temperature can be achieved with less gas, despite the change in burner-temperature configuration.
47
Mtui, P. L. "Computational Fluid Dynamics Modeling of Palm Fruit Pyrolysis in a Fast Fluidized Bed Reactor." Advanced Materials Research 699 (May 2013): 822–28. http://dx.doi.org/10.4028/www.scientific.net/amr.699.822.
Full textAbstract:
The palm fruit biomass is introduced into the pyrolysis reactor bed and the transport equations for heat, mass and momentum transfer are solved using computational fluid dynamics (CFD) technique. The Eulerian-Eulerian approach is employed to model fluidizing behavior of the sand for an externally heated reactor prior to the introduction of the biomass. The particle motion in the reactor is computed using the drag laws which depend on the local volume fraction of each phase. Heat transfer from the fluidized bed to the biomass particles together with the pyrolysis reactions were simulated by Fluent CFD code through user-defined function (UDF). Spontaneous production of pyrolysis oil, char and non-condensable gases (NCG) confirm the observation widely reported in literature. The computer model can potentially be used to assess other candidate biomass sources also to assist design of optimized pyrolysis reactors.
48
Yao, Yu Feng, Marwan Effendy, and Jun Yao. "Evaluation of Wall Heat Transfer in Blade Trailing-Edge Cooling Passage." Applied Mechanics and Materials 284-287 (January 2013): 738–42. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.738.
Full textAbstract:
Model configurations of turbine blade trailing-edge internal cooling passage with staggered elliptic pin-fins in streamwise and spanwise are adopted for numerical investigation using computational fluid dynamics (CFD). Grid refinement study is performed at first to identify a baseline mesh, followed by validation study of passage total pressure loss, which gives 2% and 4% discrepancies respectively for two chosen configurations in comparison with experimental measurements. Further investigations are focused on evaluation of wall heat transfer coefficient (HTC) of both pin-fin and end walls, and it is found that CFD predicted pin-fin wall HTC are generally in good agreement with test data for the streamwise staggered elliptic pin-fins, but not the spanwise staggered elliptic pin-fins in which some discrepancies occur. CFD predicted end wall HTC have shown reasonable good agreement for the first three rows, but discrepancies seen in downstream rows are around a factor of 2-3. A ratio of averaged pin-fin and end walls HTC is estimated 1.3-1.5, close to that from a circular pin-fin configuration that has 1.8-2.1. Further study should focus on improving end wall HTC predictions, probably through a conjugate heat transfer model.
49
Pungaiah, Sudalai Suresh, and Chidambara Kuttalam Kailasanathan. "Thermal Analysis and Optimization of Nano Coated Radiator Tubes Using Computational Fluid Dynamics and Taguchi Method." Coatings 10, no. 9 (August 20, 2020): 804. http://dx.doi.org/10.3390/coatings10090804.
Full textAbstract:
Automotive heat removal levels are of high importance for maximizing fuel consumption. Current radiator designs are constrained by air-side impedance, and a large front field must meet the cooling requirements. The enormous demand for powerful engines in smaller hood areas has caused a lack of heat dissipation in the vehicle radiators. As a prediction, exceptional radiators are modest enough to understand coolness and demonstrate great sensitivity to cooling capacity. The working parameters of the nano-coated tubes are studied using Computational Fluid Dynamics (CFD) and Taguchi methods in this article. The CFD and Taguchi methods are used for the design of experiments to analyse the impact of nano-coated radiator parameters and the parameters having a significant impact on the efficiency of the radiator. The CFD and Taguchi methodology studies show that all of the above-mentioned parameters contribute equally to the rate of heat transfer, effectiveness, and overall heat transfer coefficient of the nanocoated radiator tubes. Experimental findings are examined to assess the adequacy of the proposed method. In this study, the coolant fluid was transmitted at three different mass flow rates, at three different coating thicknesses, and coated on the top surface of the radiator tubes. Thermal analysis is performed for three temperatures as heat input conditioning for CFD. The most important parameter for nanocoated radiator tubes is the orthogonal array, followed by the Signal-to-Noise Ratio (SNRA) and the variance analysis (ANOVA). A proper orthogonal array is then selected and tests are carried out. The findings of ANOVA showed 95% confidence and were confirmed in the most significant parameters. The optimal values of the parameters are obtained with the help of the graphs.
50
Gaspar, Pedro Dinis, L. C. Carrilho Gonçalves, and R. A. Pitarma. "Detailed CFD Modelling of Open Refrigerated Display Cabinets." Modelling and Simulation in Engineering 2012 (2012): 1–17. http://dx.doi.org/10.1155/2012/973601.
Full textAbstract:
A comprehensive and detailed computational fluid dynamics (CFDs) modelling of air flow and heat transfer in an open refrigerated display cabinet (ORDC) is performed in this study. The physical-mathematical model considers the flow through the internal ducts, across fans and evaporator, and includes the thermal response of food products. The air humidity effect and thermal radiation heat transfer between surfaces are taken into account. Experimental tests were performed to characterize the phenomena near physical extremities and to validate the numerical predictions of air temperature, relative humidity, and velocity. Numerical and experimental results comparison reveals the predictive capabilities of the computational model for the optimized conception and development of this type of equipments. Numerical predictions are used to propose geometrical and functional parametric studies that improve thermal performance of the ORDC and consequently food safety.