REFLECTOR: Nose Cooler Pressure Study

[Brent Bourgeois]

Scott,
I have spent a lot of time getting my oil cooler working properly. Before cutting anything, please do a basic pressure study to understand what is going on. All you need is a plastic tube about 1 inch in front of the cooler and one in the exit duct. Route them inside and use a airspeed indicator to get an inlet press and an outlet press. The key is to maximize the differential.  
I have pages of data that prove (at least on my plane ) that the problem is positively not getting the air in, but getting it out. 
One example is : 155mph on the pitot, 88mph on the cooler face and 10 mph in the exit duct. I was eventually able to get the exit duct to 0. This 88mph proved to be the max oil cooler inlet speed all the way past 220 pitot speed. 
I think that once the inlet pressures up, the air stops entering and flows on by. Once I got max vacuum possible behind the cooler I was able to block off some of the (weird NACA type)  inlet and not raise the oil temp.
I believe the trick is to find a reverse scoop or lip arrangement that maximizes the air extraction
I had thermocouples on the cooler inlet and outlet lines. The front cooler is worth 15 to 20 degrees in oil temp.
I also found this method very useful at maximizing engine cooling while making the air inlets smaller. 
Let me know if I can help.
 
Brent 
N61VB
Std RG
 
 
 
 
 


      
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.tvbf.org/mailman/private/reflector/attachments/20091010/c5eceff3/attachment.htm>