Turbulent Flow Valve Operation


The provided model has been set up to simulate the operation of a valve.  In equilibrium the flexible plate is positioned in a way that covers the neck of the tube perfectly and no mass flow exists.  When inlet velocity (or pressure) appears, a pressure load is applied to the plate and imposed it to rotate around its top, where it is supported.  The model can be seen in Figure 1.

Figure 1: Valve model preview

 

Layout

The model contains the following parts:

  1. A flexible plate for the valve (/MAT/LAW42 and /PROP/SOLID)
  2. The main fluid domain for the air (/MAT/K-EPS and /PROP/FLUID)
  3. Inlet and outlet boundary conditions (/MAT/B-K-EPS and /PROP/FLUID)

Perpendicular to the fluid domain a no-slip wall exists, and this boundary condition will be implemented by locking the 3 translational degreed of freedom (DoFs) of the boundary fluid nodes.

Two different inlet conditions are introduced and solved.  In the first one an imposed velocity is applied to inlet nodes, while in the second one an imposed pressure is applied.  The inlet condition in both cases is applied smoothly with a ramp function and also stops smoothly with a similar slope.

An /INTER/TYPE18 is used to introduce the fluid-structure interaction between plate and flow.

The model set up is explained in detail at the attached PDF file.

 

Results

The results exhibit here correspond to the Imposed Velocity case.  Additional results for the Imposed Pressure are concluded in the attached PDF file.

In Figure 2, the Axial Velocity contour is displayed in addition with the flexible plate movement.

Figure 2: Axial Velocity

In Figure 3, the flows Relative Pressure field is displayed.

Figure 3: Relative Pressure

Figure 4, contains the contour of Turbulent Energy in the flow, here displayed in a logarithmic scale.

Figure 4: Turbulent Energy

Finally in Figure 5, Von Mises Stress of the plate are displayed.

Figure 5: Von Mises Stress

The starter (0000.rad) and engine (0001.rad) files of both imposed load cases are attached to this article.  Finally, a session file (.mvw) is attached to help visualize the simulation results.