Relevant bibliographies by topics / High speed rotor

Academic literature on the topic 'High speed rotor'

Author: Grafiati
Published: 14 March 2023

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Journal articles on the topic "High speed rotor"

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Gerlach, Martin Enno, Maximilian Zajonc, and Bernd Ponick. "Mechanical stress and deformation in the rotors of a high-speed PMSM and IM." e & i Elektrotechnik und Informationstechnik 138, no. 2 (March 2, 2021): 96–109. http://dx.doi.org/10.1007/s00502-021-00866-5.

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AbstractHigh-speed electric machines are gaining importance in the field of traction drives and aviation due to their high power density. The evaluation of the mechanical stress in the rotor is one crucial part in the design process for this type of machines. The mechanical stress cannot be measured directly. Accordingly, a validation of the calculated mechanical stress is difficult and normally not performed. Instead of the mechanical stress, the deformation at the rotor surface can be measured using a spin test machine with distance sensors. The deformation can then be used to validate the calculation results.In this paper, the mechanical load exerted on an IM rotor for a $60\,\text{kW}/20000\,\frac{1}{\text{min}}$ 60 kW / 20000 1 min high-speed electric machine and an PMSM rotor for a $75~\text{kW}/25000\,\frac{1}{\text{min}}$ 75 kW / 25000 1 min high-speed electric machine is analysed in detail. The mechanical stress and the deformation are calculated and analysed using a FEM simulation model. Then, a spin test is performed on the two rotors. First, the burst speed is determined by operating two rotor samples above their defined test speed. Then, the deformation is measured at the rotor surface for different operating speeds and the defined test speed. The measurement and the simulation results are compared and discussed.It can be shown that the two designs do not exceed the maximum mechanical stress for the defined operating range. In the deformation measurement of the IM rotor, a plastic deformation up to $\varepsilon _{\text{IM, pl}} = 8$ ε IM, pl = 8 μm and elastic deformation up to $\varepsilon _{\text{IM, el}}=22$ ε IM, el = 22 μm can be seen. In regards to plastics, PMSM rotor expands up to $\varepsilon _{\text{PMSM, pl}}= 5$ ε PMSM, pl = 5 μm. The maximum elastic deformation of the PMSM rotor is $\varepsilon _{\text{PMSM, el}}=40$ ε PMSM, el = 40 μm. The comparison of the calculated and the measured elastic deformation shows good accordance for the two rotor types. Both models are capable of describing the deformation and the state of stress in the rotors. In burst tests, both rotors withstand rotational speeds far above the defined test speed.
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Liu, Yongguang, Xiaohui Gao, Xiaowei Yang, and Yixuan Wang. "Optimization Design of the Ultra-High-Speed Vertical Rotor’s Supporting Mechanism." Mathematical Problems in Engineering 2014 (2014): 1–11. http://dx.doi.org/10.1155/2014/320240.

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How to increase the rotational speed and decrease vibration of the rotor in the acceleration has become an attractive subject, especially for the vertical rotors. This paper introduces a novel supporting mechanism to make the vertical rotor work at 80000 r/min smoothly. How to design and optimize the sensitive parameters of the supporting mechanism is the core problem to reduce the vibration in passing through critical speeds. Therefore, the FEM (finite element method) considering the gyroscopic couple is introduced to get the dynamic characteristic of the rotor system. The matching principle of the upper and lower supporting mechanism in the two-degree freedom system is extended to the multiple degree-freedom system, which is applied to optimize the parameters of the supporting mechanism combining with dynamic characteristic of the rotors system. At last, the rotor system can work at 80000 r/min smoothly in experiment.
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Yuan, Y., D. Thomson, and R. Chen. "Variable rotor speed strategy for coaxial compound helicopters with lift–offset rotors." Aeronautical Journal 124, no. 1271 (September 27, 2019): 96–120. http://dx.doi.org/10.1017/aer.2019.113.

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ABSTRACTThe coaxial compound helicopter with lift-offset rotors has been proposed as a concept for future high-performance rotorcraft. This helicopter usually utilizes a variable-speed rotor system to improve the high-speed performance and the cruise efficiency. A flight dynamics model of this helicopter associated with rotor speed governor/engine model is used in this article to investigate the effect of the rotor speed change and to study the variable rotor speed strategy. Firstly, the power-required results at various rotor rotational speeds are calculated. This comparison indicates that choice of rotor speed can reduce the power consumption, and the rotor speed has to be reduced in high-speed flight due to the compressibility effects at the blade tip region. Furthermore, the rotor speed strategy in trim is obtained by optimizing the power required. It is demonstrated that the variable rotor speed successfully improves the performance across the flight range, but especially in the mid-speed range, where the rotor speed strategy can reduce the overall power consumption by around 15%. To investigate the impact of the rotor speed strategy on the flight dynamics properties, the trim characteristics, the bandwidth and phase delay, and eigenvalues are investigated. It is shown that the reduction of the rotor speed alters the flight dynamics characteristics as it affects the stability, damping, and control power provided by the coaxial rotor. However, the handling qualities requirements are still satisfied with different rotor speed strategies. Finally, a rotor speed strategy associated with the collective pitch is designed for maneuvering flight considering the normal load factor. Inverse simulation is used to investigate this strategy on maneuverability in the Push-up & Pull-over Mission-Task-Element (MTE). It is shown that the helicopter can achieve Level 1 ratings with this rotor speed strategy. In addition, the rotor speed strategy could further reduce the power consumption and pilot workload during the maneuver.
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Han, D., and G. N. Barakos. "Variable-speed tail rotors for helicopters with variable-speed main rotors." Aeronautical Journal 121, no. 1238 (February 23, 2017): 433–48. http://dx.doi.org/10.1017/aer.2017.4.

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ABSTRACTVariable tail rotor speed is investigated as a method for reducing tail rotor power, and improving helicopter performance. A helicopter model able to predict the main rotor and tail rotor powers is presented, and the flight test data of the UH-60A helicopter is used for validation. The predictions of the main and tail rotor powers are generally in good agreement with flight tests, which justifies the use of the present method in analysing main and tail rotors. Reducing the main rotor speed can result in lower main rotor power at certain flight conditions. However, it increases the main rotor torque and the corresponding required tail rotor thrust to trim, which then decreases the yaw control margin of the tail rotor. In hover, the tail rotor may not be able to provide enough thrust to counter the main rotor torque, if it is slowed to follow the main rotor speed. The main rotor speed corresponding to the minimum main rotor power increases, if the change of tail rotor power in hover is considered. As a helicopter translates to cruise, the induced power decreases, and the profile power increases, with the profile power dominating the tail rotor. Reducing the tail rotor speed in cruise reduces the profile power to give a 37% reduction in total tail rotor power and a 1.4% reduction to total helicopter power. In high-speed flight, varying the tail rotor speed is ineffective for power reduction. The power reduction obtained by the variable tail rotor speed is reduced for increased helicopter weight.
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Ehrich, F. F., and S. A. Jacobson. "Development of High-Speed Gas Bearings for High-Power Density Microdevices." Journal of Engineering for Gas Turbines and Power 125, no. 1 (December 27, 2002): 141–48. http://dx.doi.org/10.1115/1.1498273.

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A 4.2-mm diameter silicon rotor has been operated in a controlled and sustained manner at rotational speeds greater than 1.3 million rpm and power levels approaching 5 W. The rotor, supported by hydrostatic journal and thrust gas bearings, is driven by an air turbine. This turbomachinery/bearing test device was fabricated from single-crystal silicon wafers using micro-fabrication etching and bonding techniques. We believe this device is the first micro-machine to operate at a circumferential tip speed of over 300 meters per second, comparable to conventional macroscale turbomachinery, and necessary for achieving high levels of power density in micro-turbomachinery and micro-electrostatic/ electromagnetic devices. To achieve this level of peripheral speed, micro-fabricated rotors require stable, low-friction bearings for support. Due to the small scale of these devices as well as fabrication constraints that limit the bearing aspect ratio, the design regime is well outside that of more conventional devices. This paper focuses on bearing design and test, and rotordynamic issues for high-speed high-power micro-fabricated devices.
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Bin, Guangfu, Liang Zhang, Feng Yang, and Anhua Chen. "The Influence of Ring-Speed Ratio Dynamic Change on Nonlinear Vibration Response of High-Speed Turbocharger Rotor System." Shock and Vibration 2021 (October 28, 2021): 1–9. http://dx.doi.org/10.1155/2021/9649232.

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The ring-speed ratio is a comprehensive dynamic index of floating ring bearing structure and operating parameters, which directly affects the dynamic behavior of the turbocharger rotor system. The cross stiffness of ring-speed ratio and floating ring bearing and the work of oil film force are analyzed. The influence of dynamic ring-speed ratio change on the vibration response of floating ring bearing was studied. The finite element model of the rotor-floating ring bearing system is constructed; its model parameters are verified through the measured critical rotor speed. Newmark integral method is used to analyze the nonlinear transient response. The results show that when the ring-speed ratio is between 0.18 and 0.24, the rotor is in a good operating state; when it increases from 0.24 to 0.36, the rotor vibration is dominated by frequency division, and the system will be less stable. The square of the ring-speed ratio is inversely proportional to the rotational speed of the journal where the subfrequency vibration occurs. It helps to know the nonlinear vibration by judging the journal speed when the rotor vibration occurs in subfrequency. The conclusion provides a reference for the mechanical dynamics design and intelligent management and maintenance of this kind of turbine rotors.
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Sim, Kyuho, and Daejong Kim. "Design of Flexure Pivot Tilting Pads Gas Bearings for High-speed Oil-Free Microturbomachinery." Journal of Tribology 129, no. 1 (July 27, 2006): 112–19. http://dx.doi.org/10.1115/1.2372763.

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This paper introduces flexure pivot tilting pad gas bearings with pad radial compliance for high-speed oil-free microturbomachinery. The pad radial compliance was for accommodation of rotor centrifugal growth at high speeds. Analytical equation for the rotor centrifugal growth based on plane stress model agreed very well with finite element method results. Parametric studies on pivot offset, preload, and tilting stiffness were performed using nonlinear orbit simulations and coast-down simulations. Higher preload and pivot offset increased both critical speeds of the rotor-bearing system and onset speeds of instability due to the increased wedge effect. Pad radial stiffness and nominal bearing clearance were very important design parameters for high-speed applications due to the physically existing rotor centrifugal growth. From the series of parametric studies, the maximum achievable rotor speed was limited by the minimum clearance at the pad pivot calculated from the rotor growth and radial deflection of pads due to hydrodynamic pressure. Pad radial stiffness also affects the rotor instability significantly. Small radial stiffness could accommodate rotor growth more effectively but deteriorated rotor instability. From parametric studies on a bearing with 28.5mm in diameter and 33.2mm in length, optimum pad radial stiffness and bearing clearance are 1-2×107N∕m and 35μm, respectively, and the maximum achievable speed appears 180krpm. The final design with suggested optimum design variables could be also stable under relatively large destabilizing forces.
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Rezgui, Djamel, and Mark H. Lowenberg. "Nonlinear Blade Stability for a Scaled Autogyro Rotor at High Advance Ratios." Journal of the American Helicopter Society 65, no. 1 (January 1, 2020): 1–19. http://dx.doi.org/10.4050/jahs.65.012005.

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Despite current research advances in aircraft dynamics and increased interest in the slowed rotor concept for high-speed compound helicopters, the stability of autogyro rotors remains partially understood, particularly at lightly loaded conditions and high advance ratios. In autorotation, the periodic behavior of a rotor blade is a complex nonlinear phenomenon, further complicated by the fact that the rotor speed is not held constant. The aim of the analysis presented in this article is to investigate the underlying mechanisms that can lead to rotation-flap blade instability at high advance ratios for a teetering autorotating rotor. The stability analysis was conducted via wind tunnel tests of a scaled autogyro model combined with numerical continuation and bifurcation analysis. The investigation assessed the effect of varying the flow speed, blade pitch angle, and rotor shaft tilt relative to the flow on the rotor performance and blade stability. The results revealed that rotor instability in autorotation is associated with the existence of fold bifurcations, which bound the control-input and design parameter space within which the rotor can autorotate. This instability occurs at a lightly loaded condition and at advance ratios close to 1 for the scaled model. Finally, it was also revealed that the rotor inability to autorotate was driven by blade stall.
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Manas, MP, and AM Pradeep. "Stall inception mechanisms in a contra-rotating fan operating at different speed combinations." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 234, no. 8 (December 17, 2019): 1041–52. http://dx.doi.org/10.1177/0957650919893831.

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Contra-rotating fan is a concept that can possibly replace the present-day conventional fans due to its several aerodynamic advantages. It has the potential to improve the stability limit and can achieve a higher pressure ratio per stage. One of the advantages of a contra-rotating fan is its capability to operate both the rotors at different speeds. In the present study, experiments are carried out at different speed combinations of the rotors and the stall inception phenomenon is captured using high-response unsteady pressure sensors placed on the casing upstream of the leading edge of rotor-1. The unsteady pressure data are investigated using wavelet and Fourier analysis techniques. It is observed that the mechanism of stall inception is different for different speed combinations. The pre-stall disturbances fall in different frequency ranges for different speed combinations. For the range of speed combinations investigated, the frequency of appearance of stall cells of rotor-1 does not depend on the speed of rotor-2. A higher speed of rotation of rotor-1 leads to a higher frequency of appearance of stall cells and a lower speed of rotation of rotor-1 leads to a lower frequency of appearance of stall cells. For all the speed combinations, there is a range of frequency where no disturbance is observed and this range is termed as the ‘no-disturbance zone’. Disturbances are observed at lower frequencies and at frequencies close to the blade passing frequency. In order to understand the flow physics in detail, computational analysis is carried out for different speed combinations of the rotors. For a higher speed of rotor-2, it is observed that the suction effect of rotor-2 is significant enough to pull the tip-leakage flow towards the axial direction. Thus, the suction effect of rotor-2 plays a significant role in determining the stall of the stage.
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Ma, Xunxun, Shujia Li, Wangliang Tian, Xiqiang Qu, Shengze Wang, and Yongxing Wang. "Dynamic Behavior Analysis of the Winding Rotor with Structural Coupling and Time-Frequency Varying Parameters: Simulation and Measurement." Applied Sciences 11, no. 17 (September 1, 2021): 8124. http://dx.doi.org/10.3390/app11178124.

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To satisfy the requirements of high speed, large capacity and constant winding, a textile winding rotor needs to work in a wide rotation speed range and frequently pass through critical speed points. Thus, the winding rotor adopts the flexible long shaft coupling structure and flexible support with rubber O-rings. This kind of rotor has a multi-coupling structure and frequency-dependent parameters characteristics, especially representative and universal in the dynamic analysis method of the high-speed rotor. In this paper, an approach was proposed to investigate the dynamic behavior of the winding rotor considering the flexible coupling and frequency-dependent supporting parameters. Firstly, a dynamic model of the winding rotor was established by using a Timoshenko beam element. Its dynamic behaviors were simulated by considering the time-varying rotation speed and the frequency-dependent parameters of flexible support. Secondly, a non-contact measuring device was developed for measuring the vibration displacement of the winding rotor in three different speed-up times. Finally, based on simulation and measurement data, how flexible support parameters and the speed-up time affect the winding rotor passing through the critical speed point of the rotor smoothly is revealed. The methods and findings reported here can be used for theoretical and experimental vibration analysis of other types of high-speed flexible rotors.
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Dissertations / Theses on the topic "High speed rotor"

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Miller, Philip A. "High-speed rotor testing and spin-test facility development." Thesis, University of Ottawa (Canada), 1986. http://hdl.handle.net/10393/5492.

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Papini, Luca. "Performance calculation of high speed solid rotor induction machine." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/52180/.

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Solid rotor induction machines are suitable for applications which require robustness, reliability and high rotational speed. A literature review of high speed technologies is initially presented. The current limitation and challenges are detailed based on a wide collection of data. The multi-physics aspect related with electrical machines for high speed applications are discussed providing a summary of the current state of the art. The main aim of the research was to develop a multi-physic computational environment for the design and analysis of solid rotor induction machines. The electromagnetic, thermal, structural and rotor dynamics models have been developed targeting reduced computational time and accurate predictions. Numerical techniques are proposed based on the discretisation of the computational domain. The different disciplines are linked together providing a flexible and powerful tool for the characterisation of solid rotor induction machine. Another objective was to investigate the impact of the rotor material on the electromagnetic performances of the machine. Finite Element simulation are used to account for the non linear magnetic properties. The impact on the equivalent circuit parameter is discussed and general criteria for material selection presented. Three dimensional finite element calculation are p erformed targeting the validation of the end region correction factor and select the rotor length. The performances of a 120 [kW]−25000 [rpm] solid rotor machine are compared with a caged rotor induction machine for waste heat recovery application.
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Chu, Fulei. "The vibration control of a flexible rotor by means of a squeeze-film damper." Thesis, University of Southampton, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386603.

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Irenji, Neamat Taghizadeh. "Calculation of electromagnetic rotor losses in high-speed permanent magnet machines." Thesis, University of Southampton, 1998. https://eprints.soton.ac.uk/47948/.

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High-speed permanent magnet machines are currently being developed for a number of applications including gas-turbine generator sets and machine tools. Due to the high peripheral speed of the rotor and the relatively high conductivity of the magnets used, rotor eddy current loss can be substantial. Quite low levels of loss may present a serious problem if rotor cooling is poor. The accurate calculation of these losses, and appreciation of their dependence on machine parameters, are therefore of great importance for reasons of both efficiency and temperature rise. In this, thesis, a method has been developed to evaluate the asynchronously rotating harmonics with respect to the rotor and to calculate rotor power loss caused by these harmonics. The harmonics are determined by double Fourier analysis of the normal flux density data over the rotor surface. The data is obtained from finite element magnetostatic analysis of the machine at different rotor positions, with all possible harmonic sources present, except rotor induced eddy currents whose effect on harmonics was found to be negligible. Rotor power loss is calculated for each harmonic using a 2D rectilinear current sheet model of the machine. The magnitude of the current sheet, which is placed on the inner surface of a toothless stator, is adjusted to produce the same magnetostatic normal flux density over the rotor surface as that of the corresponding harmonic. The 2D current sheet model does not allow for 3D end effects and magnet segmentation. The accuracy of the analytical rectilinear current sheet model was verified by comparison with a cylindrical FE current sheet model, and by solving a benchmark eddy current problem that can be also solved using FE steady-state AC analysis. The current sheet model was used to calculate rotor loss in a number of generic machines, with two basic types of rotor construction: 1) non-salient rotor with arc shaped surface magnets and 2) salient rotor with chord shaped surface magnets. The results show that rotor loss depends strongly on the ratio of slot opening to slot pitch (s/X.) and on the ratio of total airgap to slot pitch (g/X). For the same fundamental airgap flux density, rotor loss reduces dramatically by increasing airgap length and reducing slot opening. Increasing the number of slots also reduces the loss. The results also show that rotor loss in a generator increases as the power factor moves from lagging to leading due to the armature reaction effect. Using a conducting sleeve, instead of a non-conducting one, with conductivity in the range of practical values, increases rotor losses dramatically. Reducing magnet conductivity reduces rotor loss. Rotor power loss in machines with non-conducting sleeve is concentrated on the surface of the magnet and a small part on the surface of the hub. In machines with chord shaped magnets, the power loss density can be very high in the parts of the steel hub near the intersection of two poles where local total airgap is small. The harmonics caused by inverter switching in a motor or rectifier switching in an alternator can cause a very significant increase in rotor loss, compared to a machine with a sinusoidal mmf. The results also show that the loss depends strongly on the switching strategy, e.g., switching harmonics in 6 step mmf waveform produce 3 times more loss than a 12 step mmf waveform. Although the developed method for calculation of rotor power loss does not take the effect of magnet peripheral discontinuity or segmentation into account, it is clear that segmentation reduces power loss by interrupting the eddy current return path, specially for harmonics with long wavelengths. The effect of segmentation requires further study.
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Samadli, Vugar. "Rotor-bearing system dynamics of a high-speed micro end mill spindle." [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0015756.

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Marais, Charl Henri. "High speed flexible rotor active magnetic bearing control / by Charl Henri Marais." Thesis, North-West University, 2006. http://hdl.handle.net/10394/1084.

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The School of Electrical, Electronic and Computer Engineering at the North-West University is in the process of establishing a knowledge base on Active Magnetic Bearings (AMBs). In support of this initiative this project is aimed at characterising an in-house developed double radial heteropolar AMB system. Before characterising the AMB system the acoustic noise problem of the system had to be addressed and reduced to an acceptable level. To reduce the acoustic noise of the system a noise analysis was done to determine the source of the noise. The analysis revealed radiated noise from the electromagnets and power amplifiers (PA) and conducted noise on the signals to and from the controller. The conducted noise is reduced by using anti-aliasing (AAF) and anti-imaging filters (AIF) before and after the controller. The effect of the radiated noise is reduced by synchronising the sampling of the sensor signals with the switching of the PAS. The characterisation of the AMB system starts with a Mass-Spring-Damper (MSD) simulation which is a linear representation of the AMB system. This simulation is used to understand the basic principles of a second order system and to compare its response to the nonlinear AMB simulation. The following step in characterising the AMB system is to determine the effect of filters on the nonlinear AMB simulation and to determine the simulation characteristics. These characteristics are compared to the MSD simulation and the actual AMB system. The characteristics compared between the MSD and AMB simulations are the static, second order and dynamic stiffness. The actual AMB system was characterised before and after the AAF and AIF were implemented. This provided the opportunity to determine the effects of the filters on the actual system and not just from simulations. The characteristics measured on the actual AMB system include the static stiffness, dynamic stiffness, rotor dynamics and system sensitivity. The stiffness characteristics of the actual AMB system showed good correlation with the linear and nonlinear simulations. The measured results showed a decrease in static stiffness and an increase in system sensitivity because of the AAF, AIF and controller pole. It also showed that the effects of the filters can be reduced by moving the controller pole to a higher frequency. The characterisation of the double radial heteropolar AMB system provides a fundamental understanding of the AMB performance aiding the AMB design process.
Thesis (M. Ing. (Computer and Electronical Engineering))--North-West University, Potchefstroom Campus, 2006.
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Qazalbash, Arfakhshand. "Rotor eddy current power losses in high speed permanent magnet synchronous generators." Thesis, University of Southampton, 2014. https://eprints.soton.ac.uk/364580/.

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Rotor electromagnetic losses can be problematic in high speed permanent magnet synchronous machines, especially when the speed or the electrical loading are high and the slotting and winding configuration results in high magnitude asynchronous harmonics. Accurate estimation of these travelling flux harmonics in the initial design stage is essential, as small errors can result in significant errors in the estimated rotor losses, which could lead to misinformed design decisions. This Thesis makes a number of contributions to the subject of rotor losses in PM machines. It firstly investigates the accuracy of the commonly used current sheet method for estimating losses for each harmonic. In this method, the losses are calculated using a multi-layer model of the machine in which each asynchronous harmonic in the rotor frame is represented by current sheet on the surface of the bore of a slotless stator. The harmonics are calculated using double Fourier transform of flux density data on the surface of the magnet obtained from a number of magnetostatic finite element (FE) solutions at different rotor position. The losses are also calculated using 2D transient FEA with rotor motion, with appropriate mesh refinement and time step determined based on a mesh and time step dependence study. The results show that the current sheet method accurately calculates the losses in ring magnets if the amplitudes of the harmonics are estimated accurately. Secondly, the Thesis extends 3 analytical methods that have been reported in the literature by Zhu and Howe (1993), Gieras (2004) and et al (2006) to estimate the amplitude of the no-load asynchronous travelling flux density harmonics, the magnet flux tooth ripple harmonics, in the rotor frame. The accuracy of these methods is evaluated by comparison to those calculated using non-linear finite element analysis for variants of a particular machine. The results show that ( et al, 2006) complex permeance method provides the closest estimate, when the level of saturation in the machine is negligible. However, if the saturation, of the tooth tip in particular is significant, then all methods underestimate the amplitudes of the harmonics. And accordingly, the estimated rotor losses are grossly underestimated by a factor of 1:3 in a machine with heavy tooth tip saturation. Thirdly, the Thesis tackles the problem of losses in a loaded generator with sinusoidal currents. It is shown that the total losses in the machine are dependent on the power factor and the phase angle between the emf and current. The total loss cannot be simply calculated by adding the no-load loss due to magnet flux tooth ripple harmonics and the loss due to stator mmf asynchronous harmonics. This is due to the interaction between the stator mmf harmonics and the magnet flux tooth ripple harmonics, which need to be added vectorially. This is verified by comparing the results calculated analytically (using the most accurate ’s meth d f calculating no-load harmonics), with those obtained from transient FEA in a machine with no significant saturation. Fourthly, the Thesis investigates rotor losses in a generator with two slots per pole per phase connected to an uncontrolled diode rectifier, considering the two cases of constant current and constant voltage dc link. Two winding and rectifier configurations are considered: a 3-phase winding with a 3-phase, 6 pulse bridge rectifier and a double 3-phase winding with a 3-phase rectifier each, connected in series i.e., a 12 pulse rectifier. Both magnet flux tooth ripple and armature reaction stator mmf harmonics are considered in the calculation of rotor loss; the harmonics were added vectorially. It is shown that the machine with double 3-phase windings and 12 pulse rectifier has considerably lower rotor losses that the machine with one single 3-phase winding due to cancellation of high order harmonics. Finally, limited studies are performed in the Thesis for the calculation of rotor losses in PMSGs with different slot opening, number of slots per pole and airgap (with magnet thickness adjusted to keep the airgap flux density and emf constant). It is shown that increasing the airgap and reducing slot opening reduced the losses The results plotted in a normalised form of loss per unit rotor surface area are versus the ratios of gap/slot pitch and slot opening divided by pole pitch. These curves are shown to give reasonable quick estimates of rotor losses in machines with different sizes. Also, rotor losses are calculated in three PMSGs with different numbers of slots per pole and winding / rectifier configurations. The results show that the popular 1.5 slots per pole concentrated winding configuration have considerably higher rotor losses due to the strong second harmonic than the other machines with lap windings. The work in the Thesis was based on two-dimensional calculations, assuming ring magnets. Further work is needed to evaluate the 3D effect and magnet segmentation.
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Soliman, Mohamed Mostafa Ezzat. "An investigation into circulation control with reference to high forward speed rotor." Thesis, University of Southampton, 1985. https://eprints.soton.ac.uk/52305/.

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Christiansen, Christoffer. "Material choice for a rotor in a switched reluctance high speed motor." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-62582.

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With the increasing environmental impact from the automotive industry, electric vehicles become more and more popular. This combined with the great breakthroughs in fast electronics the switched reluctance motor (SRM) has again gained popularity in recent years. Due to its cheap and rugged construction it is a good alternative to the permanent magnet motors and to the induction motor. The ́two main problems holding the SRM back are torque ripple and the acoustic noise generated from it. A lot of research is currently being performed in order to find a solution to these issues. This thesis has investigated different materials for the rotor in a high speed SRM. Different materials have been evaluated based on both mechanical and magnetic properties. This is done through simulations of the forces acting on the rotor combined with simulations of the magnetic field. The forces are simulate in the DASSULT SYSTEMS ABAQUS program and the magnetic field is simulate using AVL FIRE. Three different kinds of alloys are investigated, two different cobalt alloys are simulated as well as a silicon alloy with pure iron as a reference. The results show that the material needs to have a yield strength of at least 349 MPa to withstand the forces affecting the rotor. And that by using the high purity cobalt-iron alloy the generated torque could be increased with up to 20.9%, but with a cost increase of 3151.9% compared to the silicon alloy.
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Ranft, Cornelius Jacobus Gerhardus. "Mechanical design and manufacturing of a high speed induction machine rotor / Cornelius Ranft." Thesis, North-West University, 2010. http://hdl.handle.net/10394/4940.

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The McTronX research group at the North–West University designs and develops Active Magnetic Bearings (AMBs). The group’s focus shifted to the design and development of AMB supported drive systems. This includes the electromagnetic and mechanical design of the electric machine, AMBs, auxiliary bearings as well as the development of the control system. The research group is currently developing an AMB supported high speed Induction Machine (IM) drive system that will facilitate tests in order to verify the design capability of the group. The research presented in this thesis describes the mechanical design and manufacturing of a high speed IM rotor section. The design includes; selecting the IM rotor topology, material selection, detail stress analysis and selecting appropriate manufacturing and assembly procedures. A comprehensive literature study identifies six main design considerations during the mechanical design of a high speed IM rotor section. These considerations include; magnetic core selection, rotor cage design, shaft design, shaft/magnetic core connection, stress due to operation at elevated temperatures and design for manufacture and assemble (DFMA). A critical overview of the literature leads to some design decisions being made and is used as a starting point for the detail design. The design choices include using a laminated cage rotor with a shrink fit for the shaft/magnetic core connection. Throughout the detail design an iterative process was followed incorporating both electromagnetic and mechanical considerations to deliver a good design solution. The first step of the iterative design process was, roughly calculating the material strengths required for first iteration material selection followed by more detailed interference fit calculations. From the detail stress analysis it became apparent that the stress in the IM rotor section cannot be calculated accurately using analytical methods. Consequently, a systematically verified and validated Finite Element Analysis (FEA) model was used to calculate the interferences required for each component. The detail stress analysis of the assembly also determined the allowable manufacturing dimensional tolerances. From the detail stress analysis it was found that the available lamination and squirrel cage material strengths were inadequate for the design speed specification of 27,000 r/min. The analysis showed that a maximum operating speed of 19,000 r/min can be achieved while complying with the minimum factor of safety (FOS) of 2. Each component was manufactured to the prescribed dimensional tolerances and the IM rotor section was assembled. With the failure of the first assembly process, machine experts were consulted and a revised process was implemented. The revised process entailed manufacturing five small lamination stacks and assembling the stack and squirrel cage afterwards. The end ring/conductive bar connection utilises interference fits due to the fact that the materials could not be welded. The process was successful and the IM rotor section was shrink fitted onto the shaft. However, after final machining of the rotor’s outer diameter (OD), inspections revealed axial displacement of the end rings and a revised FEA was implemented to simulate the effect. The results indicated a minimum FOS 0.6 at very small sections and with further analytical investigation it was shown that the minimum FOS was reduced to only 1.34. Although the calculations indicated the FOS was below the minimum prescribed FOS ? 2, the rotor spin tests were scheduled to continue as planned. The main reasons being that the lowest FOS is at very small areas and is located at non critical structural positions. The fact that the rotor speed was incrementally increased and multiple parameters were monitored, which could detect early signs of failure, further supported the decision. In testing the rotor was successfully spun up to 19,000 r/min and 27 rotor delevitation test were conducted at speeds of up to 10,000 r/min. After continuous testing a secondary rotor inspection was conducted and no visible changes could be detected. The lessons learnt leads to mechanical design and manufacturing recommendations and the research required to realise a 27,000 r/min rotor design.
Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2011.
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Books on the topic "High speed rotor"

1

Huppunen, Jussi. High-speed solid-rotor induction machine: Electromagnetic calculation and design. Lappeenranta: Lappeenranta University of Technology, 2004.

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Rutherford, John W. Shock fitting applied to the prediction of high-speed rotor noise. Moffett Field, Calif: National Aeronautics and Space Administration, Ames Research Center, 1985.

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Johnson, Wayne. Calculated performance, stability, and maneuverability of high-speed tilting-prop-rotor aircraft. [S.l.]: [s.n.], 1986.

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Johnson, Wayne. Calculated performance, stability, and maneuverability of high-speed tilting-prop-rotor aircraft. Moffett Field, Calif: National Aeronautics and Space Administration, Ames Research Center, 1987.

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Lance, Michael B. Low-speed wind-tunnel test of an unpowered high-speed stoppable rotor concept in fixed-wing mode. [Washington, D.C.]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Division, 1991.

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Y, Sung Daniel, Stroub Robert H, and United States. National Aeronautics and Space Administration. Scientific and Technical Information Division., eds. Low-speed wind-tunnel test of an unpowered high-speed stoppable rotor concept in fixed-wing mode. [Washington, D.C.]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Division, 1991.

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Y, Sung Daniel, Stroub Robert H, and United States. National Aeronautics and Space Administration. Scientific and Technical Information Division., eds. Low-speed wind-tunnel test of an unpowered high-speed stoppable rotor concept in fixed-wing mode. [Washington, D.C.]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Division, 1991.

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Lance, Michael B. Low-speed wind-tunnel test of an unpowered high-speed stoppable rotor concept in fixed-wing mode. Hampton, Va: Langley Research Center, 1991.

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Y, Sung Daniel, Stroub Robert H, and United States. National Aeronautics and Space Administration. Scientific and Technical Information Division., eds. Low-speed wind-tunnel test of an unpowered high-speed stoppable rotor concept in fixed-wing mode. [Washington, D.C.]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Division, 1991.

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United States. National Aeronautics and Space Administration., ed. Performance analysis of two early NACA high speed propellers with application to civil tiltrotor configurations. [Washington, DC]: National Aeronautics and Space Administration, 1996.

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Book chapters on the topic "High speed rotor"

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Darlow, Mark S. "Rotor Balancing Methods and Instrumentation." In Balancing of High-Speed Machinery, 53–66. New York, NY: Springer New York, 1989. http://dx.doi.org/10.1007/978-1-4612-3656-6_4.

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Darlow, Mark S. "Review of Literature on Rotor Balancing." In Balancing of High-Speed Machinery, 39–52. New York, NY: Springer New York, 1989. http://dx.doi.org/10.1007/978-1-4612-3656-6_3.

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Darlow, Mark S. "Application of the Principle of Reciprocity to Flexible Rotor Balancing." In Balancing of High-Speed Machinery, 149–58. New York, NY: Springer New York, 1989. http://dx.doi.org/10.1007/978-1-4612-3656-6_9.

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Holmes, R. "Vibration of Rotor—Bearing Assemblies." In Vibration and Wear in High Speed Rotating Machinery, 279–97. Dordrecht: Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-009-1914-3_17.

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Diana, G. "Foundation Effects in Rotor Dynamic Behaviour." In Vibration and Wear in High Speed Rotating Machinery, 581–91. Dordrecht: Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-009-1914-3_34.

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Maslen, E. H., P. E. Allaire, M. A. Scott, and P. Hermann. "Magnetic Bearing Design for a High Speed Rotor." In Magnetic Bearings, 137–46. Berlin, Heidelberg: Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-51724-2_14.

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Kaya, Faris. "Stability of Flexible Rotor Supported on Journal Bearings." In Vibration and Wear in High Speed Rotating Machinery, 559–65. Dordrecht: Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-009-1914-3_32.

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Kirk, R. G., K. A. Schoeneck, and E. A. Memmott. "Evaluation of Unexpected High Vibration on a High Speed Coupling Spacer." In Proceedings of the 9th IFToMM International Conference on Rotor Dynamics, 267–80. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-06590-8_21.

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Holmes, R. "The Control of Rotor Vibration using Squeeze-Film Dampers." In Vibration and Wear in High Speed Rotating Machinery, 399–412. Dordrecht: Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-009-1914-3_23.

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Szczygielski, W., and G. Schweitzer. "Dynamics of a High-Speed Rotor Touching a Boundary." In Dynamics of Multibody Systems, 287–98. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-82755-6_24.

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Conference papers on the topic "High speed rotor"

1

McGuiness, Daniel Tunc, Mehmet Onur Gulbahce, and Derya Ahmet Kocabas. "Novel rotor design for high-speed solid rotor induction machines." In 2015 9th International Conference on Electrical and Electronics Engineering (ELECO). IEEE, 2015. http://dx.doi.org/10.1109/eleco.2015.7394607.

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Durkin, Edward B., and John J. Schauer. "Windage Power Loss of High-Speed Generators." In ASME 1997 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/imece1997-0971.

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Abstract Direct-drive electromachines that are designed to operate at higher rotating speeds will have a windage drag that is a more significant loss factor; this loss will require greater attention in the initial machine design. Switched-reluctance machines with poled rotors can further increase windage by fluid pumping and mixing between the rotor poles. Reliable windage data for highspeed poled rotors was unavailable, so an experimental study was initiated to determine the total air friction power loss and the contributing factors to this loss. The first rotor test was with concentric cylinders to establish a valid viscous film theory. The parametric analysis then proceeded with a matrix of tests for various rotor, stator, and air gap geometries. Later tests with rotor end “shrouds” then demonstrated reduced windage loss by reducing the induced airflow and mixing in the rotor pole gaps.
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PURCELL, TIMOTHY. "A prediction of high-speed rotor noise." In 12th Aeroacoustic Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1989. http://dx.doi.org/10.2514/6.1989-1132.

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Juraj, ONDRUSKA, SOOS Lubomir, BABICS Jozef, ONDEROVA Iveta, MARGETIN Matus, and Tomas Budicky. "High-speed camera measurement of spinning rotor." In 2019 International Council on Technologies of Environmental Protection (ICTEP). IEEE, 2019. http://dx.doi.org/10.1109/ictep48662.2019.8968999.

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Kuczek, Andrzej, Farhan Gandhi, Daniel Camp, Zaffir Chaudhry, and Wenping Zhao. "Designing a High Speed Morphing Rotor Blade." In Vertical Flight Society 77th Annual Forum & Technology Display. The Vertical Flight Society, 2021. http://dx.doi.org/10.4050/f-0077-2021-16710.

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High speed rotorcraft experience regions of reverse flow over the inboard sections of blades. In these regions, because of the reverse flow, the rotor blade experiences high drag, large dynamic pitching moments, and the resulting significant vibrations. If the shape of the rotor can be changed “morphed” in the inboard section, a number of these adverse effects can be minimized. This paper outlines the approach to morphing the rotor blade to achieve two desired shapes suited for hover and forward flight. Different elements and associated risk reduction of the morphing system are discussed in details. A key element of a successful morphing structure is a flexible skin which can change shape and at the same time maintain rigidity and stiffness. The approach to achieving these conflicting goals through interleaved and off set layers of elastomers and composite sections, all co-cured in one step, is described. In addition an actuation approach and associated kinematics to achieve the shape change while minimizing actuation forces is also described. Assembly of the full-scale (in the chord-wise direction) prototype hardware of an 18% thick SC325218 airfoil is also included.
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Min, Byung-Young, Alex F. Dunn, Annie Gao, Vera Klimchenko, Claude G. Matalanis, and Brian E. Wake. "High Speed and Highly Efficient Rotor Blade Design." In Vertical Flight Society 78th Annual Forum & Technology Display. The Vertical Flight Society, 2022. http://dx.doi.org/10.4050/f-0078-2022-17457.

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Aerodynamic design of the high speed, highly efficient rotor (HSHER) blade is presented. The main objective was to design a medium-lift utility scale blade with improved high-speed performance and no penalty in hover, suitable for a singlemain rotor operating at speeds between 180 and 200 knots. To accomplish this, a design concept was chosen consisting of an advanced passive blade shape along with an adjustable trailing-edge device. Initial studies using a blade-element solver combined with a genetic algorithm were used to quickly survey large portions of the design space. Next, a CFD-based process was established whereby CREATETM-AV HELIOS was used for high-speed forward-flight simulations while hover performance was addressed using a combination of Star-CCM+ for rapid iterations and HELIOS for more detailed evaluation. While fully-automated optimization was not performed, automation was introduced wherever possible to minimize manual effort and keep the engineering effort focused on high-level strategic decisions that are still somewhat difficult to automate. The final result was a new blade design which showed significant improvements in both high-speed performance (∆L/D ~1) and hover efficiency (∆FM ~0.03) with increased thrust capability.
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Ghalamchi, Behnam, Adam Kłodowski, Jussi T. Sopanen, and Aki M. Mikkola. "Genetic Optimization of Geometrical Parameters of High Speed Rotor." In ASME 2015 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/detc2015-47291.

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The main scope of this paper is optimization of high speed rotor systems by using Evolutionary Algorithm. The target of the optimization is finding geometrical parameters of the shaft, in such a way that the critical speeds are not occurring in the operation speed range. Rotating machines have a wide range of applications in industrial machinery and applying numerical optimization techniques helps engineers to improve the performance of rotor bearing systems. A schematic of a turbine rotor system is studied. The rotor is modeled using finite element method and Timoshenko beam elements having four degrees of freedom (DOF) per node — two translational and two rotational. Critical speeds are identified using Campbell diagram. The outcome of the simulation is looking to find the widest safe margin for operation speed range without any critical speed in Campbell diagram within the operation range. Design parameters for optimization are overhang shafts lengths and diameters. Several simulation runs with different variables shows a significant effect of these parameters in dynamic behavior of the system. Comparison of the results with the basic design of turbine rotor reveals that all constraints are satisfied.
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DASH, R. "High speed rotor noise due to blade loading." In 10th Aeroacoustics Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1986. http://dx.doi.org/10.2514/6.1986-1902.

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Jung, Sung, Sung-Boo Hong, Jae Bae, Seong Hong, and Jae-Sang Park. "Rotor-Body Coupled Vibration Analysis of a High-Speed Lift Offset Coaxial Rotor." In Vertical Flight Society 77th Annual Forum & Technology Display. The Vertical Flight Society, 2021. http://dx.doi.org/10.4050/f-0077-2021-16758.

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A rotor-body coupled vibration analysis is performed for a coaxial compound lift offset (LO) helicopter. The vehicle is featured by two-bladed counterrotating rotors, main wing, and auxiliary propulsions installed at each wing tip. The fuselage analysis model is constructed considering the existing designs of conventional helicopters and tilt rotors, while the blade structural design is established modifying the original platform of XH-59A blades. As many as 17 free vibrating modes are used to represent the airframe motions after conducting a convergence test on the vibration behavior of the rotor. An in-house structural design optimization framework based on the evolutionary algorithm is employed to systematically search the best suited combinations of the objective function while meeting all the design constraints set from the static and structural dynamics perspectives. The resulting property values of the optimized configuration are correlated with those by XH-59A. The predicted results on the performance show in good agreement with the flight test data of XH-59A. The trim, loads and vibration responses are examined using either isolated coaxial LO or compound coaxial LO rotors. Key results showing the beneficial effects of LO rotor in both configurations are discussed with the shaft-fixed or shaft-free conditions of the compound helicopter in high speed flights.
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Gandhi, Farhan, Justin Pepe, and Brendan Smith. "High Solidity, Low Tip-Speed Rotors for Reduced eVTOL Tonal Noise." In Vertical Flight Society 78th Annual Forum & Technology Display. The Vertical Flight Society, 2022. http://dx.doi.org/10.4050/f-0078-2022-17440.

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This paper reports on a computational study conducted on an 8 ft diameter, fixed-pitch eVTOL rotor to examine the potential of using increased solidity and reduced tip speed to reduce the radiated acoustic signature. The study is conducted for the rotor operating in hover and in vertical climb, and at disk loadings between 6-12 lb/ft2. Relative to a "nominal" rotor of solidity σ=0.0646 (with N=2 blades and a root chord, c=15.82 cm), two 3σ rotors (the 3σ3 rotor with N=3 and root chord of 2c, and the 3σ5 rotor with N=5 and root chord of 1.2c) operating at reduced tip speed are considered, as is a single 5σ rotor (with N=5 and root chord of 2c) operating at a further reduced tip speed. The high solidity, low tip-speed rotors showed significant reductions in in-plane noise, both in hover as well as vertical climb, and over the range of disk loadings considered. The noise reductions observed with the 3σ5 rotor were significantly greater than those obtained by the 3σ3 rotor (operating at the same tip speed), and very similar to those of the 5σ rotor (operating at a lower tip speed). But the rotor torque and power penalty for the 3σ5 rotor was considerably lower than that for the 5σ rotor. Overall, a high solidity in the range of 0.2 for eVTOL rotors is quite advantageous, but further increase to around 0.3 appears acoustically unnecessary while being aerodynamically detrimental. At a solidity of 3σ, going from 3 wider chord blades to 5 narrower chord blades was hugely influential for in-plane noise reduction. Of the configurations studied, the best (the 3σ5 rotor) showed 16-24 dB reductions in in-plane noise in hover, reducing to 14.5-20 dB at 5/ms climb rate, and 12.5-16 dB at 10 m/s climb rate, with larger reductions seen at lower disk loadings. Relative to the solidity-σ rotor, the 3σ rotors had a torque penalty of 41-44%, and power penalties ranging from 1.5-5% in hover, increasing to 7.5-10% at 10 m/s climb rate.
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