Study on flow characteristics and flow ripple reduction schemes of spool valves distributed radial piston pump

2016 ◽  
Vol 231 (12) ◽  
pp. 2291-2301 ◽  
Author(s):  
Tong Guo ◽  
Shengdun Zhao ◽  
Chen Liu
Keyword(s):  
Time Delay ◽  
Design Method ◽  
Flow Characteristics ◽  
Rigid Motion ◽  
Piston Pump ◽  
Flow Ripple ◽  
Reduction Techniques ◽  
Flow Fluctuations ◽  
Ripple Reduction ◽  
Spool Valves

This paper studies the flow characteristics and flow ripple reduction techniques of a spool valves distributed radial piston pump. The mathematical models of the pump are established, and simulations based on the mathematics are performed in AMESim environment. The results indicate that the spool valves distributed radial piston pump has fewer flow fluctuations than the pump distributed by check valves, due to the rigid motion of its distribution component—the spool valves. Then, in order to reduce the flow ripple of the spool valves distributed radial piston pump, three techniques, namely, time delay, relief chamfer and transition compression filter volume, are proposed and their working principles are illustrated. Particularly, the design method of time delay is elaborated and its effectiveness is evaluated. The simulation results suggest that with the usage of the time delay method, the fluctuation range of the spool valves distributed radial piston pump is expected to be reduced by 21.7%.

Modeling and theoretical study of relief chamfer method for reducing the flow ripple of a spool valves distribution radial piston pump

2020 ◽  
pp. 095440622096562
Author(s):  
Tong Guo ◽  
Tianliang Lin ◽  
Haoling Ren ◽  
Cheng Miao ◽  
Shengdun Zhao
Keyword(s):  
Reduction Method ◽  
Theoretical Study ◽  
Piston Pump ◽  
Load Pressure ◽  
Flow Ripple ◽  
Flow Fluctuation ◽  
Ripple Reduction ◽  
Spool Valves ◽  
The Mathematical Model ◽  
Remarkable Reduction

This paper presents a study of flow ripple reduction method of a spool valves distribution radial piston pump (SVDRPP). Relief chamfers are adopted to prolong and moderate the opening processes of the delivery spool valves, thus to relieve the pressure surges as well as the consequent flow ripples, vibrations and noises. The mathematical model of this method is established and multiple numerical simulations are conducted to analyze the mechanism as well as the effectiveness of this method. According to the simulation results, different relief chamfer angles have varying influences on flow ripple reduction. Remarkable reduction of flow fluctuation from 43.4% to 36% could be achieved, when the relief chamfer angle is set around 30°. Comparisons between the relief chamfer method and the time delay method indicate that the former has better compatibility to the load pressure lower than the rated value; while the latter has better compatibility to the higher load pressure.

Theoretical and Simulation Investigations on Flow Ripple Reduction of Axial Piston Pumps Using Nonuniform Distribution of Pistons

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Fei Lyu ◽  
Shaogan Ye ◽  
Junhui Zhang ◽  
Bing Xu ◽  
Weidi Huang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Optimization Design ◽  
Nonuniform Distribution ◽  
Piston Pump ◽  
Axial Piston Pump ◽  
Flow Ripple ◽  
Distribution Rule ◽  
Dynamic Simulation Model ◽  
Ripple Reduction ◽  
Axial Piston

Abstract The output flow ripple of the axial piston pump is one of the excitation sources for the hydraulic system vibration. The amplitudes of its specific harmonics must be reduced to avoid the resonance with the hydraulic pipeline. In this paper, a method on the nonuniform distribution of the pistons is put forward to adjust the flow ripple. The deflection angles of the pistons are used to describe the distribution rule. The distribution rule is imported to the Fourier expansion of the flow rate of each single-piston chamber, and then every single flow rate is superposed to obtain the Fourier coefficient of total flow rate that becomes the function of deflection angles. After this, objective optimization design is carried out to reduce the amplitudes of specific harmonics. Finally, the dynamic simulation model of the nonuniformly distributed axial piston pump is established to verify the effects of objective optimization. The results show that the amplitude of the ninth harmonic of the flow ripple can be reduced by about 40%, and the reductions are about 99% for the 18th and 27th harmonic.

scholarly journals Flow Ripple Reduction of Axial-Piston Pump by Structure Optimizing of Outlet Triangular Damping Groove

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1664
Author(s):  
Haocen Hong ◽  
Chunxiao Zhao ◽  
Bin Zhang ◽  
Dapeng Bai ◽  
Huayong Yang
Keyword(s):  
Numerical Models ◽  
Structural Parameters ◽  
Piston Pump ◽  
Axial Piston Pump ◽  
Discharge Flow ◽  
Flow Ripple ◽  
Ripple Reduction ◽  
Simulation Results ◽  
The Time Domain ◽  
Axial Piston

The triangular damping groove on the valve plate can effectively reduce the discharge flow ripple of an axial piston pump, which structural parameters will directly affect the pump’s dynamic characteristics. Herein, a multi-parameter data-based structure optimizing method of the triangular damping groove is investigated using numerical models and simulation results. The mathematical models of a nine-piston pump are proposed and developed by MATLAB/Simulink, and the simulation results are verified by experimental results. Then, the effects of width angle and depth angle on discharge flow are analyzed. Based on the analysis of groove parameters, an optimizing index, which considering the time domain characteristics of discharge flow, is proposed. As results show, comparing with the initial specific groove structure, the amplitude of flow ripple is reduced from 14.6% to 9.8% with the optimized structure. The results demonstrate that the outlet flow ripple can be significantly reduced by the optimized structure, and the proposed multi-parameter optimizing method can play a guiding significance in the design of low-ripple axial piston pumps.

Pre-compression volume on flow ripple reduction of a piston pump

2013 ◽  
Vol 26 (6) ◽  
pp. 1259-1266 ◽  
Author(s):  
Bing Xu ◽  
Yuechao Song ◽  
Huayong Yang
Keyword(s):  
Piston Pump ◽  
Flow Ripple ◽  
Ripple Reduction

scholarly journals Finite-Time Stabilization for Stochastic Inertial Neural Networks with Time-Delay via Nonlinear Delay Controller

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Deyi Li ◽  
Yuanyuan Wang ◽  
Guici Chen ◽  
Shasha Zhu
Keyword(s):  
Neural Networks ◽  
Time Delay ◽  
Finite Time ◽  
Design Method ◽  
Sufficient Conditions ◽  
Linear Matrix ◽  
Matrix Inequalities ◽  
Nonlinear Feedback ◽  
Inertial Neural Networks ◽  
Finite Time Stabilization

This paper pays close attention to the problem of finite-time stabilization related to stochastic inertial neural networks with or without time-delay. By establishing proper Lyapunov-Krasovskii functional and making use of matrix inequalities, some sufficient conditions on finite-time stabilization are obtained and the stochastic settling-time function is also estimated. Furthermore, in order to achieve the finite-time stabilization, both delayed and nondelayed nonlinear feedback controllers are designed, respectively, in terms of solutions to a set of linear matrix inequalities (LMIs). Finally, a numerical example is provided to demonstrate the correction of the theoretical results and the effectiveness of the proposed control design method.

A Design Method for Modified Smith Predictors for Non-Minimum-Phase Time-Delay Plants with Multiple Feedback-Connected Time-Delays

2010 ◽  
Vol 36 ◽  
pp. 253-262 ◽  
Author(s):  
Iwanori Murakami ◽  
Nghia Thi Mai ◽  
Kou Yamada ◽  
Takaaki Hagiwara ◽  
Yoshinori Ando ◽  
...  
Keyword(s):  
Steady State ◽  
Time Delay ◽  
Time Delays ◽  
Large Time ◽  
Design Method ◽  
Smith Predictor ◽  
Minimum Phase ◽  
Effective Time ◽  
Phase Time ◽  
Step Disturbance

In this paper, we examine a design method for modified Smith predictors for non-minimum-phase time-delay plants with multiple feedback-connected time-delays. The Smith predictor is proposed by Smith to overcome time-delay and known as an effective time-delay compensator for a plant with large time-delay. The Smith predictor by Smith cannot be used for plants having an integral mode, because a step disturbance will result in a steady state error. Several papers considered the problem to design modified Smith predictors for unstable plants. However, no paper examines a design method for modified Smith predictors for non-minimum-phase time-delay plants with multiple feedback-connected time-delays. In this paper, we examine a design method for modified Smith predictors for non-minimum-phase time-delay plants with multiple feedback-connected time-delays.

A Fast and Effective Method for the Optimization of the Valve Plate of Swashplate Axial Piston Pumps

2021 ◽  
Author(s):  
Gianluca Marinaro ◽  
Emma Frosina ◽  
Kim Stelson ◽  
Adolfo Senatore
Keyword(s):  
Numerical Model ◽  
Dynamic Pressure ◽  
Valve Plate ◽  
Lumped Parameter Model ◽  
Piston Pump ◽  
Axial Piston Pump ◽  
Flow Ripple ◽  
Lumped Parameter ◽  
Pressure Ripple ◽  
Axial Piston

Abstract This research presents a lumped parameter numerical model aimed at designing and optimizing an axial piston pump. For the first time, it has been shown that a lumped parameter model can accurately model axial piston pump dynamics based on a comparison with CFD models and experimental results. Since the method is much more efficient than CFD, it can optimize the design. Both steady-state and dynamic behaviors have been analyzed. The model results have been compared with experimental data, showing a good capacity in predicting the pump performance, including pressure ripple. The swashplate dynamics have been investigated experimentally, measuring the dynamic pressure which controls the pump displacement; a comparison with the numerical model results confirmed the high accuracy. An optimization process has been conducted on the valve plate geometry to control fluid-born noise by flow ripple reduction. The NLPQL algorithm is used since it is suitable for this study. The objective function to minimize is the well-known function, the Non-Uniformity Grade, a parameter directly correlated with flow ripple. A prototype of the best design has been realized and tested, confirming a reduction in the pressure ripple. An endurance test was also conducted. As predicted from the numerical model, a significant reduction of cavitation erosion was observed.

Research on the Periodicity of Flow Field in a Compressor Sector Cascade

2020 ◽  
Author(s):  
Wenfeng Xu ◽  
Peng Sun ◽  
Guogang Yang
Keyword(s):  
Flow Field ◽  
Design Method ◽  
Flow Characteristics ◽  
Suction Side ◽  
Low Energy ◽  
Experimental Conditions ◽  
Flow Passage ◽  
Aerodynamic Parameters ◽  
Real Flow ◽  
Annular Cascade

Abstract Sector cascade experiments can not only be convenient to measure various aerodynamic parameters but also reveal the real flow characteristics in turbomachinery. However, the sector cascade is only a part of the whole annular cascade. The circumferential angle, the structure of the side guide plate (SGP) and the suction mode on the SGP have a great effect on the periodicity of the flow field. Therefore, the effect of structure on periodicity must be taken into consideration in order to obtain accurate data of the sector cascade experiment. In this paper, a compressor sector cascade composed of a row of adjustable guide vanes (AGVs) and a row of stators is designed. The effect of the circumferential angle, SGP structure and suction position on the periodicity is studied by numerical simulation. An optimal cascade scheme is selected for experimental research. The results show that a larger circumferential angle can weaken the effect of low-energy fluid near the SGP on the middle passages. However, given the limited experimental conditions, the circumferential angle is set at 110° which consists of 15 AGVs and 14 stators. What’s more, the SGP with the same bowed angle of AGV on both sides of the cascade can reduce the influence of the SGP on the adjacent passages and obtain a regular periodicity. The low-energy fluids still accumulate near the SGP. The suction near the stator suction side of the SGP can alleviate the blockage in the flow passage and further improve the periodicity of the cascade. Serious analysis of the experiment results have further identified that the suction near the stator suction side of SGP can make the aerodynamic parameters of the flow field uniform and lead to a good periodicity. At the same time, the feasibility of this design method is verified.

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