scholarly journals A Study On Increasing The Speed Limit of Axial Piston Pumps By Optimizing The Suction Duct

2021 ◽  
Author(s):  
Yu Fang ◽  
Junhui Zhang ◽  
Bing Xu ◽  
Chang-sheng Huang ◽  
Fei Lyv ◽  
...  
Keyword(s):  
Pressure Loss ◽  
Speed Limit ◽  
Test Rig ◽  
Cavitation Model ◽  
Axial Piston Pumps ◽  
Fluid Field ◽  
Delivery Pressure ◽  
Cavitation Intensity ◽  
Computational Fluid Dynamics Cfd ◽  
Axial Piston

Abstract The maximum delivery pressure and the maximum rotational speed determine the power density of axial piston pumps. However, increasing the speed beyond the limit always accompanies cavitation, leading to the decrease of the volumetric efficiency. The pressure loss in the suction duct is considered a significant reason for the cavitation. Therefore, this paper proposes a methodology to optimize the shape of the suction duct aiming at reducing the intensity of cavitation and increasing the speed limit. At first, a computational fluid dynamics (CFD) model based on the full cavitation model (FCM) is developed to simulate the fluid field of the axial piston pump and a test rig is set to validate the model. Then the topology optimization is conducted for obtaining the minimum pressure loss in the suction duct. Comparing the original suction duct with the optimized one in the simulation model, the pressure loss in the suction duct gets considerable reduction, which eases the cavitation intensity a lot. The simulation results prove that the speed limit can increase under several different inlet pressures.

scholarly journals Raising the Speed Limit of Axial Piston Pumps by Optimizing the Suction Duct

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Yu Fang ◽  
Junhui Zhang ◽  
Bing Xu ◽  
Zebing Mao ◽  
Changming Li ◽  
...  
Keyword(s):  
Pressure Loss ◽  
Speed Limit ◽  
Test Rig ◽  
Cavitation Model ◽  
Axial Piston Pumps ◽  
Fluid Field ◽  
Delivery Pressure ◽  
Cavitation Intensity ◽  
Computational Fluid Dynamics Cfd ◽  
Axial Piston

AbstractThe maximum delivery pressure and the maximum rotational speed determine the power density of axial piston pumps. However, increasing the speed beyond the limit always accompanies cavitation, leading to the decrease of the volumetric efficiency. The pressure loss in the suction duct is considered a significant reason for the cavitation. Therefore, this paper proposes a methodology to optimize the shape of the suction duct aiming at reducing the intensity of cavitation and increasing the speed limit. At first, a computational fluid dynamics (CFD) model based on the full cavitation model (FCM) is developed to simulate the fluid field of the axial piston pump and a test rig is set to validate the model. Then the topology optimization is conducted for obtaining the minimum pressure loss in the suction duct. Comparing the original suction duct with the optimized one in the simulation model, the pressure loss in the suction duct gets considerable reduction, which eases the cavitation intensity a lot. The simulation results prove that the speed limit can increase under several different inlet pressures.

Experimental Verification of Slipper Spinning Motion in Axial Piston Pumps

2017 ◽  
Author(s):  
Qun Chao ◽  
Junhui Zhang ◽  
Qiannan Wang ◽  
Bing Xu ◽  
Yuan Chen
Keyword(s):  
Experimental Verification ◽  
Experimental Investigations ◽  
Test Rig ◽  
Plate Interface ◽  
Pump Operation ◽  
Axial Piston Pumps ◽  
Swash Plate ◽  
Lubrication Characteristics ◽  
Spinning Speed ◽  
Axial Piston

As one of the micro motions of slipper in axial piston pumps, the slipper spinning motion has a significant effect on the lubrication characteristics of slipper/swash plate interface. However, no experimental investigations on the slipper spin were available in previous studies. The aim of this work is to design a novel test rig to measure the slipper spinning speed. A detailed description of this test rig will be given followed by a sample result of the slipper spinning motion. Also, a simulation model considering the slipper spin will be developed to investigate the effects of the spinning motion on the slipper performance. It can be concluded that the slipper spinning motion does exist during pump operation, which is helpful to prevent the slipper from further tilting motion.

Improving the Volumetric Efficiency of the Axial Piston Pump

2012 ◽  
Vol 134 (11) ◽  
Author(s):  
Shu Wang
Keyword(s):  
Operating Conditions ◽  
Volumetric Efficiency ◽  
Valve Plate ◽  
Piston Pump ◽  
Efficient Design ◽  
Axial Piston Pumps ◽  
Definition Of ◽  
Engineering Practices ◽  
First Time ◽  
Axial Piston

The volumetric efficiency is one of the most important aspects of system performance in the design of axial piston pumps. From the standpoint of engineering practices, the geometric complexities of the valve plate (VP) and its multiple interactions with pump dynamics pose difficult obstacles for optimization of the design. This research uses the significant concept of pressure carryover to develop the mathematical relationship between the geometry of the valve plate and the volumetric efficiency of the piston pump. For the first time, the resulting expression presents the theoretical considerations of the fluid operating conditions, the efficiency of axial piston pumps, and the valve plate designs. New terminology, such as discrepancy of pressure carryover (DPC) and carryover cross-porting (CoCp), is introduced to explain the fundamental principles. The important results derived from this study can provide clear recommendations for the definition of the geometries required to achieve an efficient design, especially for the valve plate timings. The theoretical results are validated by simulations and experiments conducted by testing multiple valve plates under various operating conditions.

scholarly journals Journal Bearing: An Integrated CFD-Analytical Approach for the Estimation of the Trajectory and Equilibrium Position

2020 ◽  
Vol 10 (23) ◽  
pp. 8573
Author(s):  
Franco Concli
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Pressure Distribution ◽  
Equilibrium Position ◽  
Analytical Approach ◽  
Journal Bearing ◽  
Cfd Model ◽  
Cavitation Model ◽  
Computational Fluid Dynamics Cfd ◽  
The Mathematical Model

For decades, journal bearings have been designed based on the half-Sommerfeld equations. The semi-analytical solution of the conservation equations for mass and momentum leads to the pressure distribution along the journal. However, this approach admits negative values for the pressure, phenomenon without experimental evidence. To overcome this, negative values of the pressure are artificially substituted with the vaporization pressure. This hypothesis leads to reasonable results, even if for a deeper understanding of the physics behind the lubrication and the supporting effects, cavitation should be considered and included in the mathematical model. In a previous paper, the author has already shown the capability of computational fluid dynamics to accurately reproduce the experimental evidences including the Kunz cavitation model in the calculations. The computational fluid dynamics (CFD) results were compared in terms of pressure distribution with experimental data coming from different configurations. The CFD model was coupled with an analytical approach in order to calculate the equilibrium position and the trajectory of the journal. Specifically, the approach was used to study a bearing that was designed to operate within tight tolerances and speeds up to almost 30,000 rpm for operation in a gearbox.

scholarly journals Results of identification and optimization of the parameters of axial piston pump

2021 ◽  
Author(s):  
Radovan Petrović ◽  
Nenad Todić ◽  
Slobodan Savić ◽  
Maja Andjelković
Keyword(s):  
High Resolution ◽  
Input Data ◽  
Simultaneous Presentation ◽  
Axial Piston Pump ◽  
Optimization Of Parameters ◽  
Axial Piston Pumps ◽  
Hydrodynamic Processes ◽  
3D Software ◽  
2D And 3D ◽  
Axial Piston

In the development of applicative software for mathematical modelling, identification, and optimization of parameters of axial piston pumps, special attention is paid to the real need of the engineers' practice. We used the original graphical 2D and 3D software for the application in real-time with a simultaneous presentation and processing in 24 windows of high resolution. Here it is mentioned that during optimization and identification of axial piston pump's parameters, we automatically form and present several hundreds of the complex 2D diagrams, which enables to intervene at any point in the study of hydrodynamic processes by the change of input data, where the following flow of identification and optimization is changed.

A Numerical Study of Volute Design in Centrifugal Compressor

2001 ◽  
Author(s):  
Weili Yang ◽  
Peter Grant ◽  
James Hitt
Keyword(s):  
Centrifugal Compressor ◽  
Pressure Loss ◽  
Total Pressure ◽  
Numerical Study ◽  
Flow Behavior ◽  
Numerical Results ◽  
Total Pressure Loss ◽  
Pressure Loss Coefficient ◽  
Computational Fluid Dynamics Cfd ◽  
Operating Points

Abstract Our principle goal of this study is to develop a CFD based analysis procedure that could be used to analyze the geometric tradeoffs in scroll geometry when space is limited. In the study, a full centrifugal compressor stage at four different operating points from near surge to near choke is analyzed using Computational Fluid Dynamics (CFD) and laboratory measurement. The study concentrates on scroll performance and its interaction with a vaneless diffuser and impeller. The numerical results show good agreement with test data in scroll circumferential pressure distribution at different ΛAR, total pressure loss coefficient, and pressure distortion at the tongue. The CFD analysis also predicts a reasonable choke point of the stage. The numerical results provide overall flow field in the scroll and diffuser at different operating points. From examining the flow fields, one can have a much better understanding of rather complicated flow behavior such as jet-wake mixing, and choke. One can examine total pressure loss in detail to provide crucial direction for scroll design improvement in areas such as volute tongue, volute cross-section geometry and exit conical diffuser.

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