Week 4: Project - Steady state simulation of flow over a throttle body

Objective: To set up and run the steady stae simulation for flow over a throttle body in Converge CFD and post process the results in Paraview.

Case Setup:

The geometry of throttle body is rotated about Z -axis by -90 degrees to bring it into the following orientation as shown below.

Mesh size considered: 2e-03 m

Fixed embedding is applied at the area near the throttle plate as shown to give a better analysis result near the critical area of throttle plate.

Simulation type:

General flow (Time Based)

Pressure Based Staedy State Solver

Fluid considered: Air

Simulation time parameters:

Start time- 0 cycles

End time- 15000 cycles

Initial time step- 1e-09 s

Minimum time step- 1e-09 s

Maximum time-step- 1 s

Maximum convection CFL limit (final stage) - 0.5

Boundary conditions:

Inlet pressure - 1.5e+05 Pa

Outlet pressure- 1e+05 Pa

Elbow wall temperature - 300K

Throttle plate wall temperature- 300K

Results:

Velocity contour:

The maximum velocity recorded is 310 m/s. The cross-sectional area near the throttle valve reduces and hence the velocity is maximum near the throttle plate end.

The same can be concluded from the above figure where the flow over the throttle plate shows increased velocity of air at the smaller cross-sectional area at throttle plate.

Velocity plot:

Pressure contour:

The highest pressure is indicated by red and is observed near the throttle plate as the pressure increases at this location due to the obstruction caused by the throttle plate to the airflow.

Pressure plot:

Mass flow rate plot:

The mass flow rate is seen to decrease at the inlet as the air flow starts building up inside the throttle body with an increase in mass flow rate at the outlet.

Total cell count:

The cell count is 35,000 after using 4 processors for simultion.