3D Cavitation Shedding Dynamics: Cavitation Flow-Fluid Vortex Formation Interaction in a Hydrodynamic Torque Converter

Ran, Zilin; Ma, Wenxing; Liu, Chunbao

doi:10.3390/app11062798

Cited by 14 publications

(4 citation statements)

References 29 publications

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“…The nominal torque of the pump M Bg , refers to the torque absorbed by the pump when its speed is equal to 1000 r/min in the torque section of the traction condition area. The parameter κ represents the pump capacity factor of the torque converter at a specific SR [15].…”

Section: Definition Of Torque Converter Parametermentioning

confidence: 99%

Identification and Optimization Study of Cavitation in High Power Torque Converter

Wang,

Xu,

Zhao

et al. 2024

Applied Sciences

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Aiming at the phenomenon that a high-power torque converter is susceptible to cavitation, which leads to performance degradation, first, a transient flow field model of the torque converter is established, and CFD simulation and experimental research on the torque converter are carried out to find out the speed ratio region where cavitation occurs in the torque converter as well as the rule of occurrence of cavitation, and then the cavitation identification method based on the difference between the inlet and outlet flow of the torque converter is proposed. Then, the transient flow process inside the torque converter is analyzed, and it is pointed out that the angle between the inlet angle of the stator and the outlet angle of the turbine of the torque converter, i.e., the fluid inflow injection deviation angle is an important factor affecting the cavitation phenomenon. By adjusting the key parameters of the stator blade bone line, the fluid inflow deviation angle of the torque converter stator is optimized, so that the speed ratio range of cavitation under large load conditions is greatly reduced from the original 0–0.5 (50%) to 0–0.15 (15%). Meanwhile, in terms of test performance, the nominal torque of the torque converter is greatly improved under the premise of ensuring that the performance is basically unchanged, in which the nominal torque of the test zero speed is increased by 28.7%, and the cavitation of the torque converter has been greatly improved.

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Section: Definition Of Torque Converter Parametermentioning

confidence: 99%

Identification and Optimization Study of Cavitation in High Power Torque Converter

Wang,

Xu,

Zhao

et al. 2024

Applied Sciences

Self Cite

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“…The key to cavitation simulation is to establish a proper cavitation model [19] which governs the transformation between liquid and vapor. The cavitation phenomenon of hydraulic torque converter was studied based on the Zwart cavitation model in this paper [11,13,20,21].…”

Section: Cavitation Modelmentioning

confidence: 99%

“…Zhao et al [10] studied the mechanism of bubble breakup in the hydraulic torque converter numerically by implanting bubbles in it. Guo et al [11,12] and Ran et al [13] investigated the evolution of transient cavitation in the torque converter, and the results indicated that cavitation mainly occurred in the stator, and severely reduced the performance of the torque converter. Liu et al [14][15][16] studied the influence of stator blade shape on the cavitation process of a torque converter and found out that cavitation was directly affected by internal mass flow rate, which they then improved the torque converter design considering the presence of cavitation.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Rotating Speeds on the Cavitation Characteristics in Hydraulic Torque Converter

et al. 2022

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Hydraulic torque converter is a kind of high speed rotating machine using viscosity hydraulic oil as working medium, and its internal flow field is very complex. Thereby cavitation can occur easily in the working process, resulting in severe degradation of torque converter performance, noise, vibration and even failure. In order to reveal the effect of rotating speeds on the cavitation characteristics, a full flow passage geometry and a computational fluid dynamics (CFD) model with cavitation were developed to analyze the flow behavior in the torque converter. The results show that cavitation occurs when the speed difference between pump and turbine exceeds 1400 rpm for the basic model torque converter, which could be used as a useful indicator for the occurrence and degree of severity of flow cavitation. The increase of pump rotating speed or the decrease of speed ratio will intensify cavitation, which reduces the hydraulic transmission capacity and efficiency by over 20%, and seriously alters the shape, size, vapor volume fraction and region of cavitation bubbles. In extreme cases, more than 80% of the area on the suction side of the stator blade could be covered by cavitation bubbles. Moreover, the increase of pump rotating speed also changes the critical cavitation number and extends the cavitation range towards high speed ratio conditions not previously affected. These findings can provide guidance on how to choose the operating conditions of the hydraulic torque converter and how to improve its hydrodynamic performance and stability.

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“…Dong et al [12] numerically simulated the cavitating evolution of the angular nozzle and optimized the shape of the nozzle using the RNG k−ε model. Ran et al [13] used the modified Reynoldsaveraged k−ω model to simulate the cavitating morphologies in the hydrodynamic torque converter for different working conditions. However, due to the restraints of the used model, the RANS method can only simulate the time-averaged flow, and cannot accurately predict the spatial and temporal evolution of a cavitating cloud.…”

Section: Introductionmentioning

confidence: 99%

Numerical Investigation of Cavitating Jet Flow Field with Different Turbulence Models

Li,

Xu,

et al. 2023

Mathematics

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In numerous industries such as drilling, peening, cleaning, etc., a cavitating jet is adopted. However, it is challenging to simulate the cavitating flow field numerically with accuracy. The flow field of the organ pipe cavitation nozzle is simulated in this research using the RNG k−ε, DES, and LES turbulence models. The LES model can more accurately predict the periodic shedding of a cavitating cloud, which is basically consistent with the jet morphology captured with a high−speed camera. The flow pattern, cavitating cloud evolution and shedding period of a cavitating jet are analyzed. The findings demonstrate that the LES model produces a cavitating effect inside the nozzle that is superior to those produced by the RNG k−ε and DES models. The vortex rings in the diffusion section are simulated using the LES model, which accelerates cavitation. The cavitating clouds of the organ pipe nozzle show periodic evolutions, with stages of generation, development, shedding and collapse. The periodic shedding of the cavitating clouds exhibits a similar pattern in the vorticities simulated using the LES model, and the vorticities display the small-scale structures where the cavitating bubbles collapse. This study can provide a reference for the simulation of a cavitating jet and the analysis of the cavitating mechanism.

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3D Cavitation Shedding Dynamics: Cavitation Flow-Fluid Vortex Formation Interaction in a Hydrodynamic Torque Converter

Cited by 14 publications

References 29 publications

Identification and Optimization Study of Cavitation in High Power Torque Converter

Identification and Optimization Study of Cavitation in High Power Torque Converter

The Effect of Rotating Speeds on the Cavitation Characteristics in Hydraulic Torque Converter

Numerical Investigation of Cavitating Jet Flow Field with Different Turbulence Models

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