Lee Atwood, Aerospace Legend (3 of 4)
The journey continued
Atwood maintained an active "retirement" schedule, corresponding with members of industry and authors, writing technical papers and attending as many aerospace-related events as possible. In July 1998, having just returned from a second trip in two years to England to lecture on the aerodynamic virtues of the P-51, Atwood was eager to discuss history as well as a few more recent events in aerospace.
During World War II, everyone was trying to figure out how the P-51 Mustang was out-performing German fighters as well as the British Spitfire, which had more horsepower and was 1,000 pounds lighter. The German aircraft manufacturer, Messerschmitt, was also researching the Mustang's performance to no avail.
Atwood explained, "Both the British and German engineers at the time thought you could test a scale model in a wind tunnel. But the wind tunnel models didn't generate the engine-heat factor, which we successfully controlled within the air scoop to create positive thrust. They were all looking at Mustang's laminar flow wing, which was noted for reducing air friction over the surface of aircraft wings."
Pointing to several mathematical equations, Atwood continued, "The laminar flow wing is great for jet airplanes or in a high-speed dive but had little effect on the P-51's overall performance envelope. You have to attribute the speed increase to the radiator energy recovery (positive thrust), not the characteristic of the wing itself. The wing did help in a dive -- not in level flight. I never mentioned this to anyone during the war."
Atwood credited F.W. Meredith of the RAE Farnborough, U.K., whose August 1935 report known as the Meredith Effect greatly influenced his work on the P-51 cooling radiator.
Continue to Lee Atwood, Aerospace Legend (4 of 4)