Hello everyone,

I am interested in using Fluent to simulate a valve under steady state conditions to predict the forces. The valves are fairly small (approx 9mm diameter inner shaft).

This is a problem which has been tackled previously by people who are no longer available (and unfortunately nor are their simulations). All I know is that their results did not tie up with the experiemental data. Actually I think they got close with pressure drop but the forces were way off.

What I want to know is this - is it reasonable to expect to be able to use Fluent to predict the forces accurately (within 10%) or would I just be wasting my time? And what complications would I be likely to encounter?

Regards Althea

(1). Your question is fairly common, and I also have the same questions. But I don't have the answer. (2). It is a good idea to talk to support engineers to get their professional opinion. (the pressure is easier to obtain. if not, the flow field and mass conservation will be bad. to get good prediction of total force, both the local pressure and the viscous drag must be very accurate. )

Althea,

I have recently completed some similar work for a friend of mine who is a valve design engineer. The valves were much larger, but the results were good. The calculated flow rates were good, and the computed forces were used to design a spring essential to valve operation.

If you'd like some more information, let me know (I'll be away from the office this week at an ASME meeting, so it'll be a few days before I respond to you.)

Regards, Alton