Steady state simulation for flow over a throttle body

Objectives of the Project:

(1) Perform a steady state simulation for the flow of air over a throttle body in Converge Studio and post-process the results in ParaView.

(2) Show the plots for velocity & pressure countur, and mass flow rate.

Geometry:

The throttle inside the pipe is aligned parallel to the plane of the pipe. and top open is inlet and bottom is outlet.

Mesh:

Base Mesh is small cell count is large.

• along x-direction = 0.002 m
• along y-direction = 0.002 m
• along z-direction = 0.002 m

Fixed embedding option is enabled at the walls of the pipe and at the throttle valve.

At Throttle valve

• Scale = 2
• Embedded layers = 3

At Throttle:

Intial Boundary condition:

Inlet preessure= 1.5e5=1500000.0

Outlet pressure=1e5 = 100000.0

Simulation Run Cycles = 15000

Minimum time step= 1e-9

maximum time step= 1 s

Results :

Velocity :

Pressure :

Pressure At Throttle:

Velocity At Throtle:

Glyph shows the direction of flow:

vectors on throtle valve:

velocity Streem Lines along flow direction:

velocity streem lines on throttle valve:

Velocity countour plots:

Pressure countour plot:

Cell Count:

Mass Flow Rate at inlet:

Velocity at Inlet:

Outlet Mass Flow Rate:

Outlet Velocity:

Static Pressure:

Conclusion:

• The plots for mass flow rate and average velocity shows the convergence of simulation.
• A maximum velocity of about 310 m/s is observed adjacent to the throttle valve. This is because the area is decreased suddenly and after passing through the narrow passage we see a decrease in velocity.
• Pressure variation can be seen from the pressure contour. There is a pressure drop across the throttle valve. Due to the obstruction, pressure increases before the throttle valve.
• Pressure drop measurement and prediction in curved pipes and elbow bends is
  reviewed for both laminar and turbulent single-phase fluid pow. For curved pipe
  under laminar flow, the pressure loss can be predicted both theoretically and using
  empirical relations.
• The velocity streamlines show that velocity of air increases as it flows over the throttle valve.