CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > ANSYS > FLUENT

Heat Flux Wall Boundary Confusion.

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

LinkBack Thread Tools Search this Thread Display Modes
Old   January 29, 2008, 22:28
Default Heat Flux Wall Boundary Confusion.
Posts: n/a
Hi, my model is to use a heating pipe to heat the moving air driven by rotating fan in a sealed space. My prolbem is I want to set the heating pipe as a hot wall with a certain power ouput and set the heat pipe as a thermal boundary wall: Heat Flux 2000w/m2. but the simulation result by FLuent->Report->Fluxes->Total Heat Transfer Rate shows the heating pipe is -80w. Why a negative value?

Is it that the hot wall relates to positive value in Heat Flux boundary and cold wall reate to negative value?

How does Fluent use Heat Flux thermal boundary to calculate to ensure the defined power in Heat Flux is released into fluid?

My understanding is Fluent first use the T_w=(q-q_rad)/h_f+T_f to calculate the wall temperature, then use the wall temperature to q=h_f*(T_w-T_f)+q_rad. Is it right? But I can't figure out how Fluent calculate the fluid side local heat transfer coefficient h_f.

Please advise! Thanks.


  Reply With Quote

Old   August 21, 2010, 12:20
New Member
aromal vasavan
Join Date: Jun 2010
Location: Mumbai, India
Posts: 3
Rep Power: 15
arlov is on a distinguished road
for heat transfer problems, hf is calculated from empirical relations involving Re, Pr for Nu and Nu= hf*L/k .. not sure whether fluent uses this method
arlov is offline   Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Wind turbine simulation Saturn CFX 58 July 3, 2020 01:13
Sign of Heat Flux at wall Kyung FLUENT 2 February 26, 2016 16:25
CFX does not continue Shafiul CFX 10 February 17, 2011 07:57
how to impose experimental dat as boundary conditi Rogerio Fernandes Brito FLUENT 14 November 25, 2008 05:47
Wall heat flux cujo CFX 3 November 6, 2002 03:43

All times are GMT -4. The time now is 20:34.