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Testing the Pressure Transient Flow-Force for Spool-Type Two-Way Valves.

机译：测试滑阀式两通阀的压力瞬变流量。

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摘要

An analysis is presented of the flow force acting on a two-way valve using the equilibrium condition of the piston and the equilibrium condition of fluid in the control volume. Three types of flow forces are identified: pressure-difference-induced flow force, viscous-shear-induced flow force, and momentum-induced flow force. Nondimensional analysis shows that among all steady flow force the pressure-difference-induced flow force is largest with viscous-shear-induced flow force the second and momentum-induced flow force the smallest. However, the fluid inertial-induced flow force, which is a momentum-induced flow force, is very important while the pressure transient effect caused by the slight compressibility of the fluid is negligible.;A pressure-wave generation system has been designed and built with a novel square pressure-wave generator. By turning the square pressure wave generator sustained by the variable-displacement axial piston pump, a square wave can be generated to actuate the two-way valve with fixed piston. Simulation results shows that by taking the difference between the total flow force and steady flow force, the pressure transient effect can be observed.;The first experiment is conducted on a two-way valve with extremely low leakage. The trial test on a hydraulic circuit without pressure wave generator shows that the sound wave phenomenon is very strong and there is a pressure gradient in the vertical direction. In order to reduce the influence of the two characteristics mentioned above, the 100-points average technique and pressure profile factor is introduced, and the pressure transient effect is proved to be true.;The second experiment is conducted on a two-way valve with longer valve length, stepped housing and larger clearance. Those geometry modifications are made to reduce the energy that could be reflected at the ends and reduce the pressure gradient in the vertical direction. The usefulness of those modifications is proved experimentally. Furthermore, the influence of different damping length and non-metering length is tested and it is shown experimentally that the non metering length will have a impact on the transient flow force. The reason for this influence can be partially explained by Computational Fluid Dynamics (CFD) computation. The fluid in the non-metering section will be involved in the transient flow. And the birth of vortices will make the assumption that the fluid is moving as one chunk of fluid not valid.
机译：利用活塞的平衡状态和控制容积内流体的平衡状态，对作用在二通阀上的流体力进行了分析。确定了三种类型的流动力：压差引起的流动力，粘滞剪切引起的流动力和动量引起的流动力。无量纲分析表明，在所有稳态流动力中，压差引起的流动力最大，粘滞剪切引起的流动力次之，动量引起的流动力最小。然而，由流体的可压缩性引起的压力瞬变效应可以忽略不计，流体的惯性引起的流体动力，即动量引起的流体动力，是非常重要的。带有新颖的方波压力发生器。通过转动由可变排量轴向柱塞泵支撑的方波压力发生器，可以产生方波以致动具有固定活塞的双向阀。仿真结果表明，通过求取总流力与稳态流力之差，可以观察到压力瞬变效应。首次实验是在泄漏极低的二通阀上进行的。在没有压力波发生器的液压回路上进行的试验表明，声波现象非常强烈，并且在垂直方向上存在压力梯度。为了减少上述两个特性的影响，引入了100点平均技术和压力分布因子，并证明了压力瞬变效应是正确的。更长的阀门长度，阶梯式外壳和更大的间隙。对那些几何形状进行修改以减小可能在端部反射的能量并减小垂直方向上的压力梯度。这些修饰的有用性已通过实验证明。此外，测试了不同的阻尼长度和非计量长度的影响，并通过实验表明非计量长度将对瞬态流动力产生影响。这种影响的原因可以通过计算流体动力学（CFD）计算得到部分解释。非计量部分中的流体将参与瞬态流量。涡流的产生将使流体正在流动的假设是无效的。

著录项

  • 作者

    Zhang, Shusen.;

  • 作者单位

    University of Missouri - Columbia.;

  • 授予单位 University of Missouri - Columbia.;
  • 学科 Engineering Mechanical.
  • 学位 Ph.D.
  • 年度 2011
  • 页码 162 p.
  • 总页数 162
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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