LZ-TLT From Germany, joined Apr 2001, 431 posts, RR: 0 Posted (10 years 9 months 2 weeks 13 hours ago) and read 1392 times:
Doing some research on 20's and 30's aircraft I noticed a variety of aircraft with radial engines being fitted with the so-called Townend(or Townsend) engine cowling. Could somebody explain what the reason and the benefits of using such a cowling were?
FBU 4EVER! From Norway, joined Jan 2001, 998 posts, RR: 7 Reply 2, posted (10 years 9 months 2 weeks 9 hours ago) and read 1312 times:
The Townend Ring was a British design that appeared just after the First World War and was extensively used on British A/c until the early -30's.I'm not sure but I think NACA developed this design into the NACA Cowling which had a somewhat longer chord and better airflow characteristics on the inside to aid cylinder cooling.
FBU 4EVER! From Norway, joined Jan 2001, 998 posts, RR: 7 Reply 5, posted (10 years 9 months 1 week 5 days 1 hour ago) and read 1170 times:
Yes,LZ-TLT,the result was better cooling.By tapering the aft opening,the air that was heated and expanded around the engine had to accellerate through the cowling,thus increasing cooling efficiency.
The P-51 Mustang received a 15 mph speed increase by the radiator cooling air.Sort of jet effect,really.Whether this was the case with Townend/NACA cowlings too,I don't know.