Three-Dimensional Modeling and Geometrical Influence on the Hydraulic Performance of a Control Valve

Abstract

The ability to understand and manage the performance of hydraulic control valves is important in many automatic and manual industrial processes. The use of computational fluid dynamics (CFD) aids in the design of such valves by inexpensively providing insight into flow patterns, potential noise sources, and cavitation. Applications of CFD to study the performance of complex three-dimensional (3D) valves, such as poppet, spool, and butterfly valves, are becoming more common. Still, validation and accuracy remain an issue. The Reynolds-averaged Navier–Stokes equations were solved numerically using the commercial CFD package FLUENT V6.2 to assess the effect of geometry on the performance of a 3D control valve. The influence of the turbulence model and of a cavitation model was also investigated. Comparisons were made to experimental data when available. The 3D model of the valve was constructed by decomposing the valve into several subdomains. Agreement between the numerical predictions and measurements of flow pressure was less than 6% for all cases studied. Passive flow control, designed to minimize vortical structures at the piston exit and reduce potential cavitation, noise, and vibrations, was achieved by geometric smoothing. In addition, these changes helped to increase Cv and reduce the area affected by cavitation as it is related to the jet shape originated at the valve throat. The importance of accounting for full 3D geometry effects in modeling and optimizing control valve performance was demonstrated via CFD. This is particularly important in the vicinity of the piston. It is worth noting that the original geometry resulted in a lower Cv with higher velocity magnitude within the valve, whereas after smoothing Cv increased and served to delay cavitation inception.

Numerical simulation and structure improvement of double throttling in a high parameter pressure reducing valve

“…Also, as the valve opening increases, energy dissipation increases. This phenomenon was also found by Palau-Salvador et al (2008) in a control valve. The flow field contained several vortexes and a wall jet that hit the piston with high velocity.…”

Numerical analysis of flow and cavitation characteristics in a pilot-control globe valve with different valve core displacements

“…In the grid independency test of various meshes, Chern et al (2013) also chose the pressure difference as the judgment parameter, ranging from 17.3 kPa to 21.3 kPa under similar conditions. Moreover, in a control valve (Palau-Salvador et al, 2008), with similar inlet velocities, they found that the pressure different inside changes from 0.2 MPa to 1.4 MPa. Though these published experimental or numerical data cannot validate our model directly, this comparison suggests reliability of our results and the correctness of the simulation.…”

“…Fu et al (2007) analyzed the characteristics of flow through a throttling valve with different pressures. Palau-Salvador et al (2008) carried out a 3D modeling of a control valve, and its geometrical influence on hydraulic Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering) ISSN 1673-565X (Print); ISSN 1862-1775 (Online) www.zju.edu.cn/jzus; www.springerlink.com E-mail: jzus@zju.edu.cn performance was observed. Chattopadhyay et al (2012) investigated the flow through a spool type pressure regulating valve to analyze the flow structure inside it.…”

Flow Rate Analysis of 3/2 Directional Pneumatic Valve by Means Of Ansys Cfx Software

“…The above differential partial equations are implemented in the computational module of the Ansys CFX program [7,8,10]. To effectively solve the system of equations describing the turbulent flow of the fluid, it is necessary to use boundary conditions that guarantee the uniqueness of the solution and affect the computational process in the area analyzed.…”