CFD Online Logo CFD Online URL
Home > Forums > FLUENT

heat transfer coefficient - forced convection

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

LinkBack Thread Tools Display Modes
Old   March 26, 2005, 09:32
Default heat transfer coefficient - forced convection
Posts: n/a
Dear Gurus, please help me to solve the following problem:

TARGET: to map the convective heat transfer coefficient (H.T.C., h_cell, [W/m2 K]), without using the energy equation (the "cold" approximation I mean) using a cell by cell formulation, along the frontier of a 3D very complex geometry (many characteristic lengths, confined domain, forced convection)

Velocity and pressure field are known everywhere (already computed with a RANS FVM code). Lots of velocity gradients are present inside the whole domain. The flow is incompressible with M << 0.3 and isothermal, Pr = 0.7.

Someone told me to use the flat plate approximation computing for each wall cell the local Nusselt relation like this:

Nu(x) = c * (Re(x)^n )* Pr^m

where c, n and m are the laminar/turbulent coefficient suggested by Schlichting ("B.L. Theory" pag. 298-299)

Re(x) = density * vel_cell * x / viscosity

and substituting in:

h(x) = k * Nu(x) / x

to obtain the H.T.C., h(x).

The main problem is:

> what is "x" for my 3D CFD problem cell by cell based?

> Is a correct approximation to choose the wall cell mean length as "x" supposing that this dimension is inside the boundary layer (x=Lmean_cell)?

> What is the best choose for vel_cell?

Any contribution would be really appreciated.


  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
Heat Transfer Coefficient Alberto Schroth FLUENT 14 September 9, 2015 10:00
Heat Transfer Coefficient los OpenFOAM Running, Solving & CFD 5 January 31, 2010 18:44
Changing Heat transfer coefficient Ashish FLUENT 4 February 24, 2009 08:08
heat transfer coefficient? Sima Baheri Phoenics 8 September 2, 2007 01:41
negative heat transfer coefficient Sigrid Andreae CFX 1 February 26, 2005 08:13

All times are GMT -4. The time now is 09:23.