[beastieboys]

Hello, everyone. I'm designing a gas distributor with geometry shown in the attached file.

The gas flows in from a cylindrical channel (at the bottom of the figure, diameter = 5.2 mm) and flows out from a slot (at the top of the figure, width = 150 mm and height = 0.3 mm). The B.C. for the inlet and outlet are velocity inlet and pressure outlet, respectively. The superfacial velocity at the entrance is 10.44 m/s. The operating pressure and gauge pressure are 101325 and 0 pa. I used the Laminar flow for this case.

The simulations result show that the velocity distribution is unifrom at the outlet. My colleage is skeptical about the result. To verify if the simulation results are reasonable, I expand the width of the outlet to 600 mm (the geometry of the gas inlet remains the same). I expected that the velocity in the middle part would be higehr than that of the two sides. However, the simulation results show that the gas velocity is still uniform at the ouilet in this case. I'm so confused. Can anyone give me some advice. Thanks in advance.

[Bernhard]

What are the boundary conditions did you apply? What kind of solver did you use? What is the Reynoldsnumber of the flow based on the outlet?

[beastieboys]

Thanks for your kind reply.

The following is the information you asked.

Boundary conditions:
Inlet: Velocity inlet, velocity = 10.44 m/s
Outlet: Pressure outlet, gauge pressure = 0 (operating pressure = 101325 pa)

Solver:
Pressure Based

Reynolds number:
According to the simulation results, the Reynolds number at the outlet is 200.
density is 0.65 kg/m3
velocity = 4.92 m/s
characteristic distance = 6E-04 m
viscosity is about 1E-05 kg/ms