Learning Forum

[Ananth Narayan]

Hello everyone,

 

                         I am performing a study on projectile with the effect of suppressors. But when I apply the pressure value as inlet and view the contours I get different (extremely large) that I have given. I will provide the steps which I have performed.

 

1. I have made mesh and named selection for pressure inlet, pressure outlet and bullet_wall.

2. The viscous model is K-epsilon, scalable wall function.

3. On boundary condition, I have applied a pressure inlet value as a UDF (which was compiled and loaded).

 

4. Also left Pressure outlet as default one. Question: When I leave Guage pressure as 0 pascals, does it mean the outlet wall is of atmospheric pressure..

 

5. Then choose smoothing and remeshing; 6 DOF with one degree translation. Also, dynamic mesh zones has been defined. (No problem with dynamic mesh, it worked as I needed).

6. Hybrid Initialization has been done and patched the whole region with pressure of 1.01e5 Pascal .

7. But when I open pressure contours I get to see that maximum pressure is 9.38 e9  pascals (But I guess it should be 3.75e8 Pa) but I cannot understand what's going on.

 

Function governing the Pressure is 15000000*(t-5)*(t-5).

 

 

I think I making mistakes in pressure inlets and outlet. I have also included schematic of analysis model.

 

 

[DrAmine]

Zero gauge pressure means the boundary is at the provides reference pressure.

What is the value of total pressure and static pressure at inlet after one second?

[DrAmine]

Reported by Fluent or even after two tine steps.

[Ananth Narayan]

The simulation is about to take place within almost 0.06 seconds or so. Even after running after few cases, I get run time exception. Also patching the region and view the pressure region via contours doesn't match. Like when I choose the whole domain with pressure of 1.1e5 Pa I get values:

 

 

 

The blue area depicts the atmospheric pressure but the red region is too high. According to UDF I provided, the initial pressure should be 3750e5 Pa but it is greater than that at inner region almost 3 times greater. Is anything wrong. Also have I entered correct pressure value as provided in schematic image.

[DrAmine]

Can you show with node values off and report the values I asked for.

[Ananth Narayan]

I am not sure what you are asking for. How to obtain the one you asked for?

[DrAmine]

Surface integral of pressure at inlet. Contour plot of pressure with node values disabled.