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

Heat transfer analysis of heat exchanger with complicated shape and irregular fins

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

LinkBack Thread Tools Search this Thread Display Modes
Old   September 28, 2016, 07:28
Default Heat transfer analysis of heat exchanger with complicated shape and irregular fins
New Member
Join Date: Sep 2015
Location: South Korea
Posts: 4
Rep Power: 10
Mahesh Patil is on a distinguished road
Hi all,

I am working on a project in which I have to discuss the heat transfer characteristics of complicated heat exchanger which has varying diameter with irregular fins outside and inside. (I have three fluids and one solid heat exchanger). I tried earlier discussions and other books/documentation. But it seems very confusing.

I have couple of doubts.
1) how to calculate the Reynolds number for this case?

I know,
Velocity scale = areaAve(Velocity)@inlet
Length scale = the diameter of the cylinder or chord length
density scale = areaAve(Density)@inlet
Viscosity scale = areaAve(Viscosity)@inlet

But, how to calculate characteristic length in this case.

2) How to calculate Nusselt number, heat transfer coefficient and heat transfer rate with varying Reynolds number? (This seems complicated due to complexity of geometry)


Last edited by Mahesh Patil; September 28, 2016 at 07:30. Reason: missed one important factor
Mahesh Patil is offline   Reply With Quote

Old   September 29, 2016, 12:07
Senior Member
Join Date: Feb 2011
Location: Earth (Land portion)
Posts: 1,167
Rep Power: 23
evcelica is on a distinguished road
See the FAQ for some general info on HTC and Nusselt calcs if you have not already:

You can pic any length scale you want, it is somewhat arbitrary for complex geometry. Diameter of tubes is appropriate for internal flows.
evcelica is offline   Reply With Quote


cfx, heat transfer coefficeint, heat transfer rate, nusselt number, reynolds number

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

All times are GMT -4. The time now is 18:28.