Why need CFD or Flow simulation

[Mach Number]

Hi.. We are first year team and now a days I am busy wid Solidworks Flowsimulation and Ricardo Wave. The question I need to ask from U guys dat Flowsimulation requires proper boundary conditions. I did transient analysis by putting variable pressure in runners.. and by keeping runner pressure constant and varying inlet mass flow.. But I found there is no option to constraint the lid(outlet runner) to stop the flow , since valve opens and closes but in solidworks a constant or variable condition doesnt tell dat the lid or valve has closed and it continuously flow the fluid in and out...
So the result which i get showing impractical results I think . The second thing i need to ask dat the Ricardo wave gives us much more good results in intake duct(runners) so why people use CFD or flowsimulation module?? To predict the pressure variation in plenum or it has any other reasons??

[Ben K]

I believe in Solidworks you can make a spreadsheet to show speeds similar to this video:

http://www.youtube.com/watch?v=vi8I4-Rpwio

Also--any analysis requires validation. Any team can run CFD/CAE--but if you can't validate it via testing or a flow bench, then you won't learn from your mistakes.

Good luck.

Ben

[samphlett]

Coupled 1D/3D is the answer to the boundary conditions problem.

[Mach Number]

@ Ben Kolodner :
Thanx for your your input. I has watched your given link before. In this tutorial we only setup a drop of pressure for the opening of intake valve then we again set it to ambient condition but in runners flow is pulse or fluctuating. Pressure rises above ambient near the BDC and after the valve closes the pressure variation exist in runner and manifold. The above link only simplifies the prob by stoping the lid, thats why i was asking dat if i putting the actual manifold result in runner outlet in SW flowsimulation , it gives inadequate results, vortex crosses the boundary etc..
@ samphlett..
yes we are looking forward for 1D/3D couple simulation.. thanx for your reply..