[saaguy]

I'm trying to simulate the combustion process inside a rotary engine model that I've created in Solidworks. While I have some experience with Solidworks myself, I am relatively new to SW Flow Simulator (2009 version).

I was wondering if anyone could guide me through the starting wizard for defining the operating environment? (and i'm not after the chemical processes of combustion, just the flow of air and fuel and the heat transfer involved)

Also, since the rotor in a rotary engine both rotates and orbits around an eccentric shaft, how would I model that motion in Flow Simulator?

I would appreciate any and all help on these two issues.

[auricom]

I have just asked a very similar question in another thread. If you google "Ansys CFX dynamic mesh" you will find some information that highlights capability in Ansys CFX that could be used to solve your problem. It appears as though you can take the part of the model that represents the rotor and algebraically write equations that describe its rotation and translation (orbit).
Although if you are like me, you do not have a copy of Ansys CFX, so I am also waiting on a resonse in this forum to see if cosmos floworks can do something similar to this. If it cannot I might try to get a copy of CFX.

[Nika]

You have to create a volume, which covers all rotating parts.
This volume has to be defined as rotating region.
If there are any parts inside this volume, which should not rotate, then specify these as Boundary conditions -> wall -> real wall -> stator.

Use a fine mesh at the boundary between rotating and stationary mesh, so a 64-bit machine would be great.

[Nika]

Originally Posted by saaguy

I'm trying to simulate the combustion process inside a rotary engine model that I've created in Solidworks. While I have some experience with Solidworks myself, I am relatively new to SW Flow Simulator (2009 version).

I was wondering if anyone could guide me through the starting wizard for defining the operating environment? (and i'm not after the chemical processes of combustion, just the flow of air and fuel and the heat transfer involved)

Also, since the rotor in a rotary engine both rotates and orbits around an eccentric shaft, how would I model that motion in Flow Simulator?

I would appreciate any and all help on these two issues.

in addition to my post below :
if you want calculate a specific flow rate, define this as inflow (or outflow) and the other opening as static pressure.
if you are free concerning the operation point, define all BC as pressure opening

[auricom]

I know that you can tell cosmos floworks that an object may be rotating or translating, but it will only do the analysis for that snap shot in time during which the mobile object is at its current modeled position. This makes it OK for analysis of stream engines or rotodynamic compressors, but as I understand it, it will not physically re-orient the model to reflect rotation or translation while this sim is running. Is this correct, or an I wrong on this?

Max

[Nika]

Of course, it is a simulation, an approximation of the reality. But whether you rotate an object in a stationary mesh or you rotate the mesh around a stationary object, makes no big difference.
At every iteration a specific cell of the rotating mesh passes the data on to a different cell of the stationary mesh. So, if the mesh is fine enough it could be an acceptable result.

[auricom]

I'm not sure that you understand what I am trying to do...
Are you saying that I can have a poppet valve open, allowing air into a cylinder, then close the poppet valve 20 miliseconds later, and find out how much air went into the cylinder? That would be great if I could.

[Nika]

I'm sorry, but this will not be possible. You can only try it in seperate configurations.
As far as I know, Ansys is the only one who offers such kind of simulation with direct interaction between solid and fluid.
Maybe I misunderstood your problem.

[JBeilke]

http://www.cd-adapco.com/press_room/...cs/25/ice.html

[hadikhayyamian]

Hello Nika,
Thanks for your information,

I would like to know whether assembly configuration attributes (Like Mates) will affect our measurment.
I mean if I fix rotating elements (like blades) while I define them as rotating region in Floworks analysis, what will be the result?

thanks in advance.