Optimization of cross angle based on the pumping dynamics model

Engineering Applications of Computational Fluid Mechanics

Hong

et al. 2016

Fang (2017) Analysis of the flow dynamics characteristics of an axial piston pump based on the computational fluid dynamics method, Engineering Applications of Computational Fluid Mechanics, 11:1, 86-95, DOI: 10.1080/19942060.2015 ABSTRACTTo improve its working performance, the flow ripple characteristics of an axial piston pump were investigated with software which uses computational fluid dynamics (CFD) technology. The simulation accuracy was significantly optimized through the use of the improved compressible fluid model. Flow conditions of the pump were tested using a pump flow ripple test rig, and the simulation results of the CFD model showed good agreement with the experimental data. Additionally, the composition of the flow ripple was analyzed using the improved CFD model, and the results showed that the compression ripple makes up 88% of the flow ripple. The flow dynamics of the piston pump is mainly caused by the pressure difference between the intake and discharge ports of the valve plates and the fluid oil compressibility. ARTICLE HISTORY

Section: Model Gridmentioning

confidence: 99%

Analysis of the flow dynamics characteristics of an axial piston pump based on the computational fluid dynamics method

Engineering Applications of Computational Fluid Mechanics

Hong

et al. 2016

“…Traditionally, Poiseulle equation and Couette equation are used to evaluate the leakage via piston/ cylinder interface (Ivantysyn and Ivantysynova, 2001;Ma et al, 2010b;Guan et al, 2014). A more precise way is via using the 2D Reynolds equation of lubrication (Xu et al, 2013;Mizell and Ivantysynova, 2014;Wegner et al, 2014;Lin and Hu, 2015).…”

Section: Introductionmentioning

confidence: 99%

Characteristics of volumetric losses and efficiency of axial piston pump with respect to displacement conditions

et al. 2016

JZUS-A

Self Cite

Abstract:A good efficiency performance of a pump over a wide range of displacement conditions is crucially important for variable pump control systems to save energy. However, according to the literature, less attention has been paid to the understanding of the efficiency, leakage flow, and compression flow characteristics of the pump with respect to displacement conditions. In this study, a test bench was built, and a novel explicit volumetric loss model was proposed to investigate these problems. The overall efficiency is found to drop considerably with the decreasing displacement. The volumetric losses range from 13% to 47% of the total power losses of pump at the rated speed, under the conditions of pressure ranging from 5 to 35 MPa and displacement ranging from 13% to 100% of full displacement. The highest proportion of compression flow losses in the total volumetric losses of pump at the rated speed can reach up to 41% when the pressure and displacement are greater than 30 MPa and 88% of full displacement, respectively; after that, the proportion gradually decreases with decreasing displacement. However, the leakage flow generally increases with decreasing displacement, or may decrease first and begin to increase after the minimum with the further decrease of displacement. In the components of leakage of slipper/swash plate pair, the squeeze leakage is found to reach a magnitude equal to that of the Poiseuille leakage. The findings can guide the further research and design of pumps with better efficiency performance.

“…A simulation conducted by Ma et al (2010) using computational fluid dynamic technology revealed that the flow coefficient C fluctuates around 0.7. Thus, it is set as 0.7 in the simulation model.…”

Section: Simulation Modelmentioning

confidence: 99%

“…The bulk modulus of hydraulic oil is a function of pressure and temperature, which was measured by Ma et al (2010) at two temperatures and five pressure levels from 4 to 24 MPa with a step of 5 MPa. The bulk moduli at other temperatures and pressures are calculated using an interpolation method.…”

Section: Simulation Modelmentioning

confidence: 99%

Effects of index angle on flow ripple of a tandem axial piston pump

J. Zhejiang Univ. Sci. A

2015

Self Cite

Abstract:A high noise level is one of the prominent shortcomings of an axial piston pump which is widely used in industrial and mobile applications. In this paper, a simulation model of an axial piston pump is developed based on a single piston chamber model, for capturing the dynamic characteristics of the discharge flow rate. The compressibility of fluid and main leakages across different friction pairs are considered. The simulation model is validated by a comparison of discharge flow ripple with the measured results using the secondary source method. The main cause of flow ripple is identified by a comparison of the frequency spectrums of actual and kinematic flow ripples. Flow rates with different index angles are analyzed in time and frequency domains. The findings show that an index angle of 20° is the most effective in reducing the flow ripple of a tandem axial piston pump, because the frequency contents at odd harmonics can be cancelled out. A sensitivity analysis is conducted at different pressure levels, speeds, and displacement angles, which reveals that with an index angle of 20°, the sensitivity of flow ripple can be reduced by almost 50% over a wide variety of working conditions.