## Fluids

#### How to connect/couple two surfaces/zones by mass flow

• Fabian_S
Subscriber

Hallo,

I've modeled a 4-Way 3-Position hydraulic valve in Ansys Fluent with the four ports Inlet, Port-A, Port-B and Outlet. Each port is defined as a single zone. I was able to simulate different cases with different boundary condition, except the case with Port-A and Port-B connected. To compare my model with data sheets, I need to connect both ports like a short circuit during a whole switching cycle of my transient simulation. I would like to implement something like "mass flow Port-A = mass flow Port-B" independent of the flow direction.

Maybe I missed a basic function, but I can't find a solution to my problem on my own.

I would be very pleased  if someone had an idea to solve my problem.

• Karthik R
Hello:
Maybe I don't fully understand your question, but can you not use the Mass Flow Inlet condition and provide an equal flow rate at these ports?
Karthik
• Fabian_S
Subscriber
Hallo
Thank you, Karthik for your fast response.
I will try to specify my Problem.
The modeled valve has four connections, like in the first picture on the left. The case I want to investigate is when Port-A and Port-B are connected like in the firs picture on the right.
The inlet is a pressure inlet with a pressure of 5 MPa and the outlet is a pressure outlet with a pressure of 0 MPa. To connect Port-A and Port-B I don't want to model a pipe. I would like to set something up where the surface of Port-A and Port-B were connected. The mass flow exiting Port-A should therefore re-enter Port-B and vice versa. The mass flow itself is unknown and should be determined by the simulation itself. Today, I've tried to set up a solution with the Symmetry function, but without success.
Valve schematic:

• Rob
Ansys Employee
Expressions might work. Why would material pass from B to A and how will you account for the pressure loss and any other changes?