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-   -   Boundary Conditions - Transient Simulation (https://www.cfd-online.com/Forums/cfx/101901-boundary-conditions-transient-simulation.html)

miki256 May 16, 2012 14:40

Boundary Conditions - Transient Simulation
 
Dear friends,
I would like to make a transient simulation of combustion process in Ansys CFX 13.0 and I have need to set Normal Speed for Air flow as follow (for steady-state simulation):

Insert Boundary>Boundary Details>Mass And Momentum>Option – Normal Speed>Normal Speed>15 m.s^-1

But if I want to make a transient simulation I would like to define Normal Speed for Air flow as function of time. For example:

Vair flow= A*t^3+B*t^2+C*t+D,m/s
where A,B,C,D are constants,
t-time,s
or
Insert Boundary>Boundary Details>Mass And Momentum>Option – Normal Speed>Normal Speed> Enter Expression>2,5*t^3+6*t^2+2*t+1,8.

So, how can I express this dependence if I want to do this transient simulation?


Thank you in advance

miki

evcelica May 16, 2012 18:23

A[m*s^-4]*t^3+B[m^s^-3]*t^2+C[m*s^-s]*t+D[m*s^-1]

miki256 May 18, 2012 01:22

Dear evcelica,
Thank you so much!


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