Hard cooling data???

[cncdoc]

Does anyone have any ballpark cooling data on the 13B? I am looking for total BTUH or kCal/hr for the coolant and the oil temp loss requirements at the normal set figures (75 degrees F sea level etc 6000 rpm). I guess the auto guys don't worry about it too much and it's not addressed as well (if it gets hot, put a bigger one in there!..)on the rotary sites.

Hopefully it will be less than 700 BTUH..

 

Thanx.

Kevin

[Jim Sower]

The best source I know of is Ed Anderson on the rotary list. He is an excellent engineer and does careful research. He's making more progress at understanding and quantifying what I regard as a black art than anyone else I'm familiar with. There's been a very interesting thread on cooling the entire past month, and will continue for quite a while I believe.

 

Most of the flying rotarys seem to be RVs and the issues confronting tractor and pusher instalations are different in many ways.

 

There are no easy answers. Join the list, spend some time in the archives and have a ball.

 

Hope to see you there .... Jim S.

[Jim Sower]

Kevin,

Here's an example of the thread I mentioned above in the Rotary list:

+++++++++++++++++++++++++++++++++++

>

> Hi, Ed....Do I understand correctly that only one of these cores would be

> needed to cool 160 HP at 120 MPH? Thanks. Paul Conner

>

 

Hi Paul,

 

No - sorry if I misled you. Unless the pass several weeks of studying K&W are for naught, its fairly clear that for 160HP at 120MPH you need two GM cores. The point I was trying to make is that the calculations show that for the frontal area of the GM cores that their optimum thickness for 120 MPH is closer to 3" or the core you mentioned to Marv rather than the GM cores 3.6".

 

I have however progress to the point (I think) where I could calculate the effectiveness of other cores (like car type radiators) in providing cooling. The only problem would be I would need some parameters that are normal not available. One is the ratio of open area to frontal area of the core. Similarly the dimensions of the holes (air passages) (width and height) as well as the normal dimensions (width Height thickness). Also whether the fins are smooth, slotted (the cores fins are slotted) or corrugated.

 

I obtained those dimension from the GM core and the calculated results appears to be close to what folks are observing.

 

Found an old Naca paper translated from a German study written back in 1939 that is surprisingly similar to the K&W work. It does have some different stuff, a bit more on the use of cowl flaps which is interesting. Also, it shows that as the radiator heats up, it offers more air resistance and less cooling effectiveness and that the area of the cowl flap opening is important in getting good results from them.

 

Ed Anderson