- **CFX**
(*https://www.cfd-online.com/Forums/cfx/*)

- - **Introducing normalized velocity**
(*https://www.cfd-online.com/Forums/cfx/113057-introducing-normalized-velocity.html*)

Introducing normalized velocityDear friends
I would like to introduce normalized velocity profile as an input. The velocity changes with respect to time under different condition. So I did normalized the data (0 to 1). Now the output data has no unit ( assume I am correct). How to introduce this normalized data to the input boundary condition in the velocity field? Thank you for your kind attention Regards Govind |

Velocity boundaries need an input in units of length/time, so you just need to un-normalise it.
Alternately you can trick CFX into using non-dimensional inputs providing you work the unit change through all units in the simulation and end up with a consistent set of units (which are actually unitless :) ). Using this you can do non-dimensional simulations in CFX. |

Quote:
That means I have to choose simply all the dimensionless number to velocity unit. Am I correct? If this is the case, the maximum velocity becomes 1 m/s and minimum velocity becomes 0 m/s. in my data at t=0, the normalized value is 0.7070 . this value corresponds to 0.2375 m/s ( un normalized value). In a global initialization, what is the initial value at t= 0 s? . Is it 0.7070 or 0.2375? ( I put at t=0, velocity 0.7070 m/s). If I use normalized value , one simulation is sufficient. Am I correct? If I want to change the input parameter for the next result, what is the procedure? ( Note: If I use normalized method other set of readings also traces the same value ) Thank you Regards Govind |

No matter what you do the unit system you use has to be consistent.
It can either be a non-dimensional scheme or a quasi-dimensional scheme (simply un-normalising your velocities). What is the best approach will depend on what information you know and what you are trying to achieve. |

Quote:
I will try my best Regards Govind |

Quote:
Dear friends I have an CEL expression for velocity U(t)= U(max)[1+sin (4*pi*f*t- (pi/2))] for my simulation I want to change U(max ) everytime. If I convert into normalized, I got a same curve for all the U(max) values. Now, is there any way to proceed with single simulation and get multiple results for different U(max) values? Regards Shashwat |

Do you want to see the result for a series of U(max) values in a steady state simulation? The best way to do this is to either script up a series of steady state runs, possibly using other runs as intial conditions to speed sonvergence; OR use a multiple configuration def file to do multiple setups OR use workbench to do a parametric sweep.
There's three ways of doing it, you choose the one you like the best. |

Quote:
No my simulations are transient simulation. can you please explain bit. I thought in the following way,please correct me if I am wrong. the normalized velocity curve is simillar for the series of U(max).so find the normalized factor . DO one simulation un-normalized velocity as an input and find the result in cfx post. If I want to do series of u (max) , can I simply multiply with normalized factor?.simillary ,can I multiply the normalized factor with result in cfx post?. is the way correct ? Thank you Regards |

All times are GMT -4. The time now is 21:12. |