Converge CFD

Transient simulation for flow over a throttle body using Converge CFD

OBJECTIVE-Simulate Flow of fluid over a throttle body in converge studio and post process the results using transient state solver.

Geometry-The .stl file for 3d geometry of elbow was imported to converge.

Setup-

Applications-

-General flow

Materials-

-Air

Simulation Parameters:

-Transient solver

-Start time-0, End time-0.01 s

-Intial time step=minimum time step=1e-9 s

-Maximum time step=1 s

Boundary conditions-

-Inlet- INFLOW-Total pressure-150000 pa

-Outlet- OUTFLOW-Total pressure-100000 pa

-Elbow wall- WALL

-Throttle-WALL

Throttle position:

0-0.002 s rotation by 25 degrees

0.002-0.004 s remain at 25 degrees

0.004-0.008 s come back to original position

Regions & Initialization:

Boundaries are assigned to region

Temperature and pressure set to 300K and 101325pa

Species-Air

Grid Control:

dx=0.02 m, dy=0.02 m, dz=0.02 m

Fixed embedding:

At trottle

Type-Boundary, Mode-Permanent

Scale-3, Embed layers-2

Mesh-

Embedding was done at the throttle boundary which is like local refinement of mesh.This helped in capturing detailed physics near the throttle.

Total cell count:

The total cell count is not constant because the trottle keeps changing the position, so the mesh changes with time.

Mass flow rate at inlet and outlet:

Pressure plot at inlet and outlet:

Velocity plot at inlet and outlet:

Results-

Velocity Contour:

Pressure Contour:

Velocity Streamlines at 0.002 s:

Calculation of end time:

Characterstics length= 0.2 m

inlet velocity= 200 m/s

Time for 1 pass= 0.2/200=0.001s

For 10 pass, end time= 0.01 s

Animation of velocity contour:

Conclusion:

1. The transient state simulation for fluid over a throttle body was run successfully.

2.  The total cell count is not constant because the trottle keeps changing the position, so the mesh changes with time.

3. We can see high pressure at throttle upstream and low pressure at downstream due to flow separation.

4. Embedding ensured detailed capture of physics around the throttle wall.

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *