Transient simulation of flow over a throttle body

Objective:

To conduct transient state simulation of flow over a throttle body.

Theory:

Case setup:

Inlet pressure = 150000 Pa

Outlet Presure = 100000 Pa

Inlet temperature = 300K

Outlet temperature = 300K

No of cycles = 15000

Min time step = 1e-9

Max time step = 1

Base grid size = 0.002m

Fixed embedding scale = 3

Rotating angle = 0 to 25 degrees between 0 to 2, 25 degrees between 2 to 4, 25 to 0 between 4 to 8 ms and stay 0 till end

Geometry:

Mesh:

The base mesh of 2mm is used for entire body. The mesh for throttle valve is refined.

Velocity Contour:

The velocity contour is cut along plane normal to z axis. Above represents the trend of velocity at inlet and outlet. The maximum velocity can be observed at the gap between throttle and elbow of pipe.

Pressure Contour:

The pressure contour is cut along plane normal to z axis. Above represents the trend of pressure along the length of pipe.

Cell Count:

Above represents the trend of cells along the profile.

Mass flow rate:

Above represents the trend of mass flow rate at inlet and outlet.

Below is the link for animation of simulation

The mass flow rate in the elbow changes when the throttle valve is changing the position.