I recall an article on some experiments done on inclined radiators in race cars.

 

Basically the figures that George mentioned were quoted in the source.  However (big however) what may not have been clearly pointed out was that the major part of the reason cooling effectiveness (not efficiency) increased was that inclining the heat exchanger permitted you to install ever larger area cores in the same size duct.  So the increase in cooling effectiveness by inclination was in large part due to the larger size radiator permitted by inclined placement in the duct.

 

For example take a duct that is 24” wide (X) and 12” high (Y) at zero degree inclination.  If you incline the radiator by 30 deg and then increase its height to again fill the duct,. you can get an approx 15% increase in the frontal size of the radiator (in the same 24x12 duct).  At 60 deg you could gain approx 100% increase in frontal size by again increasing the height of the core to fill the duct.  . Naturally that aids in getting rid of the heat.  They also point out the larger core adds weight until you reach a point where the adverse effect of the heavier radiator core offset its benefit (this was all addressing their use in race cars).

 

The source indicated that up to 30Deg the drag increases and heat transfer goes down due to uneven air flow distribution and disturbances – apparently above that angle this adverse effect decreases and of course you have the much larger frontal area..

 

At least that is what I recall.  If anyone is interested I’ll see if I can find the article in my files

 

Ed

 

 

Thomas,

Nice research.

I found my notes on inclined radiators, they state

1. 0-20/30* will decrease cooling and increase drag.

2. Over 30* things improve.

3. At approx 55* cooling effectiveness is 30% greater than non-inclined rads

and drag is less by 20%.

 

George; do you have the source for that info? It may be a good idea to verify this information.  I don’t recall the specifics; but what I do recall is that the conclusion was configuration dependant, and should not be taken as generally applicable.  Sorry, but I don’t remember what the factors were; maybe something about the configuration of the core.

Or maybe my memory just isn’t right.  Worth checking.

All

__________ Information from ESET NOD32 Antivirus, version of virus signature database 3267 (20080714) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com