Air flow through intake manifold
 

Hi my name is Genis I'm new here and I started with Ansys 4 months ago but I'm a rookie especially in Fluent. I need help with a Fluent simulation where the flow mass rate on entry became different with the mass flow rate on outlet and I don't know why, does anybody know which could be the problem? I fix an atmospheric pressure for inlet and a flow mass for outlet.

Here some details:

My simulation consists on intake manifold system for a four cylinder engine. I want to know if the design distribute the same air on the different manifolds. For this I have the fluid body meshed with Body sizing and Inflation function with a total of 490.000 cells. For Fluent I'm working on Steady with k-epsilon and k-omega SST viscous models. The Boundary conditions are: on entry a pressure inlet of atmospheric value, 3 outlets with wall type and 1 of the open with a mass flow of 0,06 kg/s Outward (obtained of an Engine Simulation software when the engine works at 9000 rpm). The idea is to analyze the pressure lost and prove that it's similar for each runner. An special detail is that the system have a restrictor with 20 mm of dimeter, and that causes a high velocities around 200 m/s. For this I run the model with ideal gas.

The problem is when I look at the post process results and see that the flow mass rate on inlet doesn't match with the flow mass rate on outlet. Running the model with a mass flow rate of 0,015 kg/s works well and entry a outlet matches but not for high velocities. I show you an image of an intake manifold with the same design I have.

Thanks for any help and sorry for my english,

Genis.

https://fsoulu.files.wordpress.com/2...ng?w=500&h=234