Steady state simulation of flow over a throttle body

OBJECTIVE:

• Simulate Flow of fluid over a throttle body in converge studio and post-process the results.
• Post process the results and show pressure and velocity contours.
• Show the plots for pressure, velocity, mass flow rate and total cell count.
• Create an animation in which its throttle movement should be visible.

SOFTWARE ENVOLVED:

• Converge Studio
• Cygwin
• Paraview

PROFILE GEOMETRY:

INITIAL BOUNDARY CONDITIONS:

• The flow is general flow.
• The air contains a predefined mixture of oxygen and nitrogen.
• The pressure at the inlet and outlet is 1.5 and 1 bar.
• The Prandtl and Schmidt no for the given profile are 0.9 and 0.78.
• The no of the cycle performed is 15000.

MESH SIZE:

• The base mesh grid is dx=dy=dz=0.004.
• The fixed embedding has been done on the throttle valve, given the scale of 2 and no of the layer is 2.

RESULTS:

After preprocessing and postprocessing the data using converge studio and paraview, the following results are as followed.

Base Mesh

(dx=dy=dz=0.004)

Pressure Contour

Velocity Contour

Total Cell Count

• The Total no of cell count is 11000.
• The ranks define the number of processors ie, Rank0 defines the first processor and so on.
• Each processor has the cell count of 2750.

Total Pressure

• The plot defines the total pressure at the inlet is steady throughout the cycle.
• The total pressure at the outlet gets an increase from 1 bar to 1.35 bar around 4000 cycles and after that, it attains the steady state.

Velocity plot

• The plot defines the symmetry in the average velocity at the inlet and outlet boundaries.
• Both the boundaries attain steady state after the 4000 cycles.

Mass flow rate plot

• The plot defines the symmetry in the mass flow rate at the inlet and outlet boundaries.
• Both the boundaries attain steady state after the 4000 cycles.

The streamline flow animation:

CONCLUSION:

• Due to the fixed embedding of the throttle valve, the simulations near to it becomes clear as the number of cell count got increased in the specified region.
• The velocity increases near the elbow valve since the area is less and pressure get dropped in the region which causes the velocity to increase.
• The velocity of the fluid decreases when it collides with the throttle valve.
• It also causes the formation of the stagnation point due to an increase in the pressure and decreasing of velocity.