CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum

2-D HVAC problem

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Display Modes
Old   July 4, 1999, 15:51
Default 2-D HVAC problem
Posts: n/a
In my line of business, plant facilities, I have little need for CFD, but a couple of years ago, I wrote a small bit of code based on the Stream-Function/Vorticity Formulation. This worked well enough, and have not needed and CFD since. However, I would like to simulate a problem where pressure is taken into account. Specifically, I need to simulate air flow in a long, pressurized, ceiling plenum for a cleanroom. From what I have read, introducing a pressurization function into my current code is not reccommended. I'm a rank-amateur at CFD, and my company wont pay $ thousands a year for a commercial program that will seldom be used. I'm not interested in heat transfer, just the fluid dynamics. I guess what I'm looking for is some advice on how to formulate the algorithm. I using a PC, and writing in powerbasic. What method would be best for a novice like me?
  Reply With Quote

Old   July 4, 1999, 19:41
Default Re: 2-D HVAC problem
T.J. Wanat
Posts: n/a
Check out "Numerical Heat Transfer and Fluid Flow" by Patankar. It's got a layman's description of how the method is derived and works.
  Reply With Quote

Old   July 4, 1999, 20:37
Default Re: 2-D HVAC problem
John C. Chien
Posts: n/a
(1). I think you are happy with your 2-D incompressible world. The real world is too complicated and there is no real interest from the company side. So, the solution has to be simple. (2). The solution is: you can still use your 2-D stream function/ vorticity formulation. All you need to do is to integrate the momentum equation to get the pressure distribution. (3). After you have obtained the converged solution from the stream function/vorticity equations, you should have the velocity distribution (u and v are related to the stream function through the definition). The next step to do is to integrate the momentum equation, say x-momentum equation, from the inlet (where the pressure is specified) to the exit. This can be done along the grid line in the middle of the channel, or through every grid lines. (4). At the end of the integration process, you should have the pressure distribution from the inlet to the exit.
  Reply With Quote

Old   July 6, 1999, 18:48
Default Re: 2-D HVAC problem
Md. Ziaul Islam
Posts: n/a
It seems like you are working on viscous incompressible flows. The solution of the Navier-Stokes equations for a viscous incompressible fluid in terms of pressure is given below.

C = (1/density of air)(kinematic viscosity/r)**2

Re = Radial Reynolds Number

S = Swirl Reynolds Number

P - Pinfinity = - C(Re**2 + S**2) + Z dP/dZ

Reference :

" Modeling Flow and Heat Transfer in Vortex Burners " Anatoly Borissov, Vladimir Shtern and Fazle Hussain, University of Houston, Mechanical Engineering Department, Houston, Texas 77204-4792 AIAA Journal, Vol. 36, No.9, September 1998

Although, the authors in this journal worked on gas turbine, still the generalized equations can be applied to solve fluid dynamics problems in HVAC and other fields of widespread technological importance. Good Luck!!
  Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
engineFoam new mesh problem ayhan515 OpenFOAM Meshing & Mesh Conversion 5 August 10, 2015 08:45
Problem with interFoam; Wave/wiggle alpha1 behavior JonW OpenFOAM 3 February 23, 2013 21:41
UDF compiling problem Wouter Fluent UDF and Scheme Programming 6 June 6, 2012 04:43
Gambit - meshing over airfoil wrapping (?) problem JFDC FLUENT 1 July 11, 2011 05:59
Problem in implementing cht tilek CFX 3 May 8, 2011 08:39

All times are GMT -4. The time now is 05:19.