How can we use dimensionless values as inlet and out let BC?

granzer · November 7, 2019, 03:16

I am trying to simulate the quasi 1D compressible nozzle flow in the 'CFD the basics with application' by John Anderson(as a 2D case). All the BCs and IC are given as dimensionless values in the book. Is there a way to use these dimensionless values to run a fluent 2D simulation?

LuckyTran · November 7, 2019, 11:58

Not really, no. Fluent and most general purpose software are dimensional solvers for practical reasons. You need to convert the non-dimensional BC's into dimensional ones. Dimensionless BC's and IC's are cute but practically useless anyway unless ALL the governing equations are also dimensionless.

granzer · November 8, 2019, 00:27

[QUOTE=LuckyTran;749176]Not really, no. Fluent and most general-purpose software are dimensional solvers for practical reasons. You need to convert the non-dimensional BC's into dimensional ones. Dimensionless BC's and IC's are cute but practically useless anyway unless ALL the governing equations are also dimensionless.[/QU]

Is there a way we can convert the dimensionless quantities in the Anderson book into dimensional ones? ....i don't think fixing a random value will work..

granzer · November 8, 2019, 00:29

Quote:

Originally Posted by LuckyTran

Not really, no. Fluent and most general-purpose software are dimensional solvers for practical reasons. You need to convert the non-dimensional BC's into dimensional ones. Dimensionless BC's and IC's are cute but practically useless anyway unless ALL the governing equations are also dimensionless.

Is there a way we can convert the dimensionless quantities in the Anderson book into dimensional ones? .... I don't think fixing a random value will work.

November 7, 2019, 03:16	How can we use dimensionless values as inlet and out let BC?	#1
granzer Senior Member Mandeep Shetty Join Date: Apr 2016 Posts: 188 Rep Power: 10	I am trying to simulate the quasi 1D compressible nozzle flow in the 'CFD the basics with application' by John Anderson(as a 2D case). All the BCs and IC are given as dimensionless values in the book. Is there a way to use these dimensionless values to run a fluent 2D simulation?

November 7, 2019, 11:58		#2
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,762 Rep Power: 66	Not really, no. Fluent and most general purpose software are dimensional solvers for practical reasons. You need to convert the non-dimensional BC's into dimensional ones. Dimensionless BC's and IC's are cute but practically useless anyway unless ALL the governing equations are also dimensionless. granzer likes this.

November 8, 2019, 00:27		#3
granzer Senior Member Mandeep Shetty Join Date: Apr 2016 Posts: 188 Rep Power: 10	[QUOTE=LuckyTran;749176]Not really, no. Fluent and most general-purpose software are dimensional solvers for practical reasons. You need to convert the non-dimensional BC's into dimensional ones. Dimensionless BC's and IC's are cute but practically useless anyway unless ALL the governing equations are also dimensionless.[/QU] Is there a way we can convert the dimensionless quantities in the Anderson book into dimensional ones? ....i don't think fixing a random value will work..