Variable non-dimensional CFX
I want to compare the results obtained in the CFX with another study but in this, they standardized the continuity and the Navier-Stokes equations it is possible to make non-diemnsional the equations in the CFX???
I understand that using one cell I can work the equations that I create I pleasure. what I want to know if the variables of the program (the continuity and the Navier-Stokes equations) can be standardized (non-adimensional) and since it becomes? if the answer is negative as I compare a study of simulation in CFX with another non-dimensional? |
CFX is a dimensional solver. As long as you give it a consistent set of input units to work in then it is fine. You can define a unit system which is non-dimensional if you like.
Obviously you can compare a dimensional and non-dimensional solution. The non-dimensional result can be made dimensional by assuming a length, time and any other necessary scales and scaling the results to give a dimensional result. Alternately you can non-dimensionalise the CFX result. Either is fine. |
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No, you can use the same non-dimensional system (eg U*=U/Uref where U* is the non dimensional velocity, U is the dimensional velcoity and Uref is the reference velocity) used to define to define the non-dimensional system in the first place to the CFX results.
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thanks Glenn... understand.
Now, already like establishing my non-dimensional system, but like I can cause that the CFX recognizes my non-dimensional variables to me. I explain myself: Quote:
Velocity u (non-dimensional) = Velocity u/Free Stream. Velocity u = Velocity that calculates the CFX Free Stream = Velocity of reference (I define) Q: Since I do so that the CFX works with my new variable (non-dimensional Velocity or) instead of velocity u? reading HELP CFX consegui this: (Example) EXPRESSIONS: Re = 4.29E6 [] Bel = 60 [m s^-1] L=1.044 [m] Visc=areaAve (density) @in*Vel*L/Re PROPERTIES: Option = Ideal Gas Molar Mass = 2.896E1 [kg kmol^-1] Dynamic Viscosity = Visc Specific Heat Capacity = 1.E3 [J kg^-1 K^-1] Thermal Conductivity = 2.52E-2 [W m^-1 K^-1] In theory it could make this but parameters like the Velocity u, v, w or distance x, y, z or density where not to look for them to change them by my expressions non-dimensional. I would want to settle down this non-dimensional system this way: Velocity u (non-dimensional) = Velocity u/Free Stream. Velocity v (non-dimensional) = Velocity v/Free Stream. Velocity w (non-dimensional) = Velocity w/Free Stream. X (non-dimensional) = X/Diam. Y (non-dimensional) = Y/Diam. Z (non-dimensional) = Z/Diam. t (non-dimensional) = (t*Free Stream) /Diam. same question, since I do so that the CFX works with my new variables and not with which it has by defect? excuses by my English… are very bad :o |
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