Velocity field as initial condition

[Dawek]

Hello, I'm working on a simulation of flow in combustion chamber. I am trying to setup the model in order to validate the model based on data from experiment. Since I'm using Pressure inlet as a boundary condition for inflow to said combustion chamber instead of using the whole cylinder for the simulation (which would be very computation resource consuming) I tried to pre-calculate a velocity field inside of my simulation domain to subside the missing cylinder volume. Then I wanted to adjust the model with said velocity field as initial condition, however it seems like the only possibility is to use integral values for the entire simulation domain. Is there really no way to use already simulated velocity field as an initial condition for further simulations (sure with the same mesh)?

Thanks for any reply

[cfdgeek]

Hi 

Do you use Creo Flow? If so, for the same mesh, just continue run will use the current flow filed as the initial condition. 

[Dawek]

Hi

Yes I do and I already tried proposed solution. The thing is that I change a lot of initial conditions compared to the "starting" simulation and continuing the run simply ignores my new initial conditions and uses all of the previous results to continue the simulation. For example the temperature in my "starting" simulation is 550K but i set the initial temperature in my fluid domain as 490K but after first computation cycle the temperature is 550K (without any dip to 490K).

I might be just doing something wrong, but I have no idea what would that be.

[cfdgeek]

Hi,

So the purpose of changing initial BC is mainly for speeding up the convergence? You know that the initial condition can not affect your final converged solution. 

If you have different initial conditions you want to maintain for different cases, it will be easier to use multiple projects which is introduced in creo 9.  Please contact your ptc support team and let Simerics team know. We may help you upgrade CFA to have that capabilities now. thanks.

[Dawek]

Hi, 

Well only partially. To explain what I'm doing. I do have data on intake and compression strokes (pressure, thermals, etc.) of an engine with pre-chamber. I also have data on air-fuel mixture composition of both combustion chamber and pre-chamber at the end of intake stroke (at BDC). Since there is already some velocity field formed after the intake stroke, it affects formation of flow field during compression stroke. But since I have mixture distribution data beginning from BDC I cannot simulate the intake flow formation with appropriate mixture distribution, hence why I'm trying to simulate only velocity field on the intake stroke and I'm trying to "import" it as an initial condition to continue the simulation from the point of known mixture distribution. 
Thanks, I'll make sure to contact them with my issue.