Rayleigh number Custom field function

praphul · October 13, 2017, 01:26

Hi ,

I would like to plot a custom field function of Rayleigh number with time in Fluent. ( I am simulating a natural convection problem in a 3D rectangular enclosure ). The formula for Rayleigh number is $Ra = \frac{g \beta \Delta T L^{3}}{\nu \alpha}$ . I would like to get the values of these fluid properties from the simulation.

The problem is i am unable to find these properties and constants $g, \beta ,\Delta T , L , \nu , \alpha$ inside custom field function in fluent while defining the cff. Is there a solution to this problem ? Can anyone guide me on how to implement it ?

Thanks in advance.

praphul · November 4, 2017, 10:26

It will be certainly helpful if some can help me on this issue. It might seem trivial to some of you but can help a lot in getting ahead in the learning curve.

ViLaks · November 13, 2017, 02:48

Quote:

Originally Posted by praphul

Hi ,

I would like to plot a custom field function of Rayleigh number with time in Fluent. ( I am simulating a natural convection problem in a 3D rectangular enclosure ). The formula for Rayleigh number is $Ra = \frac{g \beta \Delta T L^{3}}{\nu \alpha}$ . I would like to get the values of these fluid properties from the simulation.

The problem is i am unable to find these properties and constants $g, \beta ,\Delta T , L , \nu , \alpha$ inside custom field function in fluent while defining the cff. Is there a solution to this problem ? Can anyone guide me on how to implement it ?

Thanks in advance.

You know g is 9.81; Your beta is thermal expansion coefficient, which is 1/T (1/fluid temperature). L is characteristic length which is Volume of the body/Surface area of the body; Dynamic viscosity (Nu) , Diffusivity (alpha) can be easily found onlne at the corresponding fluid temperature

October 13, 2017, 01:26	Rayleigh number Custom field function	#1
praphul Member Praphul T Join Date: Dec 2013 Location: Bangalore, India Posts: 32 Rep Power: 13	Hi , I would like to plot a custom field function of Rayleigh number with time in Fluent. ( I am simulating a natural convection problem in a 3D rectangular enclosure ). The formula for Rayleigh number is $Ra = \frac{g \beta \Delta T L^{3}}{\nu \alpha}$ . I would like to get the values of these fluid properties from the simulation. The problem is i am unable to find these properties and constants $g, \beta ,\Delta T , L , \nu , \alpha$ inside custom field function in fluent while defining the cff. Is there a solution to this problem ? Can anyone guide me on how to implement it ? Thanks in advance.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
decomposePar problem: Cell 0contains face labels out of range	vaina74	OpenFOAM Pre-Processing	37	July 20, 2020 06:38
[mesh manipulation] Mesh Refinement	Luiz Eduardo Bittencourt Sampaio (Sampaio)	OpenFOAM Meshing & Mesh Conversion	42	January 8, 2017 13:55
Compressor Simulation using rhoPimpleDyMFoam	Jetfire	OpenFOAM Running, Solving & CFD	107	December 9, 2014 14:38
DecomposePar unequal number of shared faces	maka	OpenFOAM Pre-Processing	6	August 12, 2010 10:01
Error with Wmake	skabilan	OpenFOAM Installation	3	July 28, 2009 01:35

November 4, 2017, 10:26		#2
praphul Member Praphul T Join Date: Dec 2013 Location: Bangalore, India Posts: 32 Rep Power: 13	It will be certainly helpful if some can help me on this issue. It might seem trivial to some of you but can help a lot in getting ahead in the learning curve.