Steady-State simulation for flow over a throttle body-CONVERGE

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

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

Setup-

Applications-

-General flow

Materials-

-Air

Simulation Parameters:

-Pressure based steady state solver

-Start time-0, End time-15000 cycle

-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

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:

Cell count is 42000

Graphs to check the attainment of steady state of the solution from line plotting module:

The below graphs contain the mass flow rate, velocity , pressure at inlet and outlet respectively.We can see from these graph that the solution has attained a constant value after around 5000 cycles in all the plots.So we can conclude that the solution has reached a steady state.

Mass flow rate at inlet and outlet:

Pressure plot at inlet and outlet:

Velocity plot at inlet and outlet:

Results-

Velocity Contour:

Pressure Contour:

Pressure Contour on Trottle:

velocity vectors:

Animation of velocity contour:

Conclusion:

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

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

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