Design and Numerical Simulation of Piezoelectrically-Driven Single Piston Pump With Distributing Valves

2020 ◽  
Author(s):  
Nanyue Xu ◽  
Bin Wang ◽  
Rongfei Yang
Keyword(s):  
Numerical Simulation ◽  
Piston Pump ◽  
Low Flow ◽  
Driving Frequency ◽  
Flow Ripple ◽  
Delivery Performance ◽  
Active Membranes ◽  
Delivery Pressure ◽  
Computational Fluid Dynamics Cfd ◽  
Typical Design

Abstract In this paper, a piezoelectrically driven single piston pump is designed for high delivery pressure and large displacement. It is composed of a piezoelectric stack, a hydrostatic amplifier and a plunger with two check valves from a radial plunger pump commercially available. Passive check valves instead of active membranes in the pump allow higher pressure delivery, and the hydrostatic amplifier is adopted for larger displacement of the pump. In order to study delivery characteristic of a piezoelectrically driven single piston pump, numerical simulation of unsteady flow inside the pump is conducted by computational fluid dynamics (CFD). Moving mesh technique is adopted to characterize the behavior of two check valves for oil distributing. Influences of typical design and operation parameters on delivery performance of the single piston piezo pump are analyzed. The results show that, driving frequency and spring stiffness of the valves and chamber configuration should be properly designed for stable oil delivery with low flow ripple as possible. Numerical simulation is valid to describe the behavior of the pump, on target for theoretical reference to its counterparts used in miniature EHA actuators.

scholarly journals The Problem of Accounting for Heat Exchange between the Flow and the Flow Part Surfaces When Modeling a Viscous Flow in Low-Flow Stages of a Centrifugal Compressor

2020 ◽  
Vol 10 (24) ◽  
pp. 9138
Author(s):  
Sergey Kartashov ◽  
Yuri Kozhukhov ◽  
Vycheslav Ivanov ◽  
Aleksei Danilishin ◽  
Aleksey Yablokov ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Centrifugal Compressor ◽  
Calculation Model ◽  
Flow Coefficient ◽  
Low Flow ◽  
Relative Width ◽  
Adiabatic Wall ◽  
Flow Part ◽  
Computational Fluid Dynamics Cfd

In this paper, we review the problem of accounting for heat exchange between the flow and the flow part surfaces when creating a calculation model for modeling the workflow process of low-flow stages of a centrifugal compressor using computational fluid dynamics (CFD). The objective selected for this study was a low-flow intermediate type stage with the conditional flow coefficient Փ = 0.008 and the relative width at the impeller exit b2/D2 = 0.0133. We show that, in the case of modeling with widespread adiabatic wall simplification, the calculated temperature in the gaps between the impeller and the stator elements is significantly overestimated. Modeling of the working process in the flow part was carried out with a coupled heat exchanger, as well as with simplified accounting for heat transfer by setting the temperatures of the walls. The gas-dynamic characteristics of the stage were compared with the experimental data, the heat transfer influence on the disks friction coefficient was estimated, and the temperature distributions in the gaps between disks and in the flow part of the stage were analyzed. It is shown that the main principle when modeling the flow in low-flow stage is to ensure correct temperature distribution in the gaps.

The Dynamics of a Cantilevered Pipe Aspirating Fluid Studied by Experimental, Numerical and Analytical Methods

2010 ◽  
Author(s):  
Dana Giacobbi ◽  
Stephanie Rinaldi ◽  
Christian Semler ◽  
Michael P. Pai¨doussis
Keyword(s):  
Analytical Model ◽  
Low Flow ◽  
Computational Fluid Dynamics Cfd ◽  
Computational Structural Mechanics ◽  
Cantilevered Pipe ◽  
The Galerkin Method ◽  
Csm Model ◽  
Ocean Mining ◽  
Flow Experiments ◽  
Flow Velocities

This paper investigates the dynamics of a slender, flexible, aspirating cantilevered pipe, ingesting fluid at its free end and conveying it towards its clamped end. The problem is interesting not only from a fundamental perspective, but also because applications exist, notably in ocean mining [1]. First, the need for the present work is demonstrated through a review of previous research into the topic — spanning many years and yielding often contradictory results — most recently concluding that the system loses stability by flutter at relatively low flow velocities [2]. In the current paper, that conclusion is refined and expanded upon by exploring the problem in three ways: experimentally, numerically and analytically. First, air-flow experiments, in which the flow velocity of the fluid was varied and the frequency and amplitude of oscillation of the pipe were measured, were conducted using different elastomer pipes and intake shapes. Second, a fully-coupled Computational Fluid Dynamics (CFD) and Computational Structural Mechanics (CSM) model was developed in ANSYS in order to simulate experiments and corroborate experimental results. Finally, using an analytical approach, the existing linear equation of motion describing the system was significantly improved upon, and then solved via the Galerkin method in order to determine its stability characteristics. Heavily influenced by a CFD analysis, the proposed analytical model is different from previous ones, most notably because of the inclusion of a two-part fluid depressurization at the intake. In general, both the actual and numerical experiments suggest a first-mode loss of stability by flutter at relatively low flow velocities, which agrees with the results from the new analytical model.

Turbine Airfoil Heat Transfer Predictions Using CFD

2005 ◽  
Author(s):  
Anil K. Tolpadi ◽  
James A. Tallman ◽  
Lamyaa El-Gabry
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Turbulence Modeling ◽  
Three Dimensional ◽  
Numerical Approach ◽  
Navier Stokes ◽  
Design System ◽  
Computational Fluid Dynamics Cfd ◽  
Turbine Airfoils ◽  
Typical Design

Conventional heat transfer design methods for turbine airfoils use 2-D boundary layer codes (BLC) combined with empiricism. While such methods may be applicable in the mid span of an airfoil, they would not be very accurate near the end-walls and airfoil tip where the flow is very three-dimensional (3-D) and complex. In order to obtain accurate heat transfer predictions along the entire span of a turbine airfoil, 3-D computational fluid dynamics (CFD) must be used. This paper describes the development of a CFD based design system to make heat transfer predictions. A 3-D, compressible, Reynolds-averaged Navier-Stokes CFD solver with k-ω turbulence modeling was used. A wall integration approach was used for boundary layer prediction. First, the numerical approach was validated against a series of fundamental airfoil cases with available data. The comparisons were very favorable. Subsequently, it was applied to a real engine airfoil at typical design conditions. A discussion of the features of the airfoil heat transfer distribution is included.

scholarly journals Research of Pressure Fluctuation with Experiment and Numerical Simulation for Dredging Pump

2021 ◽  
Vol 2097 (1) ◽  
pp. 012028
Author(s):  
Mingming Liu ◽  
Haifei Zhuang ◽  
Lei Cao
Keyword(s):  
Numerical Simulation ◽  
Pressure Fluctuation ◽  
Flow Instability ◽  
Simulation Method ◽  
Design Flow ◽  
Low Flow ◽  
Pressure Amplitude ◽  
Main Frequency ◽  
Simulation And Experiment ◽  
Fluctuation Amplitude

Abstract In order to reveal the dredge pump flow instability characteristics, the cavitation and pressure fluctuation in experimental study are carried out, the pressure fluctuation frequency domain and time domain characteristics of three different position inside the volute are analyzed. The results showed that, before cavitation, the main frequency at different positions at different flow rates is 1 times the main frequency of the blade. The fluctuation amplitude near the volute tongue and diffusion section is slightly larger than that at other positions. Before cavitation, the fluctuation amplitude at the same position off design flow is slightly higher than that near the design flow. Cavitation has little influence on the main frequency of the pressure fluctuation. After cavitation, the pressure fluctuation amplitude in the low flow point and the position of the volute tongue under each condition has little change, but cavitation aggravates the pressure fluctuation in the other conditions. Besides, the comparison between simulation and experiment results shows the dredge pump performance curve is in good agreement with the simulation curve, and the simulation results of pressure amplitude at different positions are basically consistent with the experiment results, which verifies the reliability of the numerical simulation method.

scholarly journals Investigation on Dynamics of Sediment and Water Flow in a Sand Trap

2020 ◽  
Vol 14 ◽  
Keyword(s):  
Flow Behavior ◽  
Vertical Component ◽  
Low Flow ◽  
Hydropower Project ◽  
Cfd Model ◽  
Critical Flow Velocity ◽  
Settling Basin ◽  
Sediment Removal ◽  
Sand Trap ◽  
Computational Fluid Dynamics Cfd

Sediment and flow dynamics in a sand trap of Golen Gol hydropower project in Pakistan was evaluated using a Computational Fluid Dynamics (CFD) model. Sediment Simulation in Intakes with Multi Block Options (SSIIM) CFD model was used to simulate the sediment and flow behavior in the sand trap. Numerical simulation results demonstrated that the horizontal and vertical component of velocities at any region of settling basin was less than the designed critical flow velocity of the sand trap. The design with respect to dimensions and proportioning of the sand trap were found appropriate for inducing low flow velocities throughout the settling basin of the sand trap supporting the deposition of sediments. The results obtained from simulation further presented the 100% removal of the desired sediments (particle size class ≥ 0.205 mm diameter) could be achieved in the sand trap. All this verify the design of sand trap is in accordance with the desired designed sediment removal efficiency of the sand trap.

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.

Analysis and Numerical Simulation of no Reacting Swirling Flow by Using URANS Approach

2021 ◽  
Vol 57 ◽  
pp. 67-79
Author(s):  
Merouane Habib ◽  
Senouci Mohammed
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Swirling Flow ◽  
Navier Stokes ◽  
Governing Equations ◽  
Simulation Based ◽  
Classical Models ◽  
Recirculation Zones ◽  
Computational Fluid Dynamics Cfd ◽  
Volume Method

In this paper, we investigate the no-reacting swirling flow by using the numerical simulation based to the unsteady Reynolds-averaged Navier-Stokes approach. The numerical simulation was realized by using a computational fluid dynamics CFD code. The governing equations are solved by using the finite volume method with two classical models of turbulence K-epsilon and Shear Stress K-ω. The objective of this paper is therefore to evaluate the performance of the two models in predicting the recirculation zones in a swirled turbulent flow. The current models are validated by comparing the numerical results of the axial, radial and tangential velocities to the experimental data from literature.

scholarly journals Thermal behavior of ceramic particles in a gaseous medium at high temperature

2020 ◽  
Vol 307 ◽  
pp. 01056
Author(s):  
Abderrahmane AISSA ◽  
Abdel-Nour ZAIM ◽  
M SAHNOUN ◽  
Redouane FARES ◽  
M ABDELOUHAB ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Spherical Particle ◽  
Atmospheric Pressure ◽  
Computational Analysis ◽  
Gaseous Medium ◽  
Plasma Jet ◽  
Spray Process ◽  
Plasma Spray Process ◽  
Proposed Model ◽  
Computational Fluid Dynamics Cfd

Numerical simulation of the interaction between the spherical particle and plasma gas is carried out. The aim of this study is to investigatethermal transfer between the plasma gas and solid particle during the plasma spray process and to validate the well-known empirical correlation of the Ranz and Marshall. In the conditions of molten or semi-molten states of prepared substrate, the medium (plasma jet) can affect the high velocities of particles. On the basis of direct numerical simulation, the computational analysis has been carried out by using computational fluid dynamics (CFD) of heat transfer in atmospheric pressure and mid-temperature range (3000k–12000k) of a plasma flow over a spherical particle. Our proposed model improves correlation with experiments compared to the existing approaches in the literature.

Sign in / Sign up

Export Citation Format

Share Document