Biographical Memoirs Volume 86 (2005) / Chapter Skim
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Robert Thomas Jones
Robert Thomas Jones
Pages 240-259
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From page 241... ...
T.Jones's idea of sweepback for transonic and supersonic flight. This idea, of which Jones was one of two independent discoverers, was described by the late William Sears, a distinguished aerodynamicist who was a member of the National Academy of Sciences, as "certainly one of the most important discoveries in the history of aerodynamics." It and other achievements qualifyJones as among the premier theoretical aerodynamicists of the twentieth century.
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From page 242... ...
Returning to Macon, he joined the locally based Marie Meyer Flying Circus, a stunt flying group typical of the time. As an employee of the circus he received flying lessons in exchange "for carrying gas and patching wing tips," though he would not solo until more than 50 years later.
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From page 243... ...
R.T. returned home to Macon, where he used his time to study books on aerodynamics, such as Max Munk's Fundamen tats of Fluid Mechanics for Aircraft Designers.
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From page 244... ...
By the time his nine months were up, his exceptional talents had become apparent, and his supervisors retained him at subprofessional levels by temporary and emergency reappointments. A permanent professional appointment as an engineer at the initial civil-service grade, however, required a bachelor's degree.
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From page 245... ...
This idea originated in 1944 in the course of a wartime assignment to help develop guided missiles. It derived from the design by the Ludington-Griswold Company of a dartshaped glide bomb having a wing of narrow triangular planform.
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From page 246... ...
A few months later while exploring the more complex nonlinear equations of compressible flow, he realized that introducing the approximation of the long, narrow wing gave him the same results as his incompressible analysis. This result implied that for slender wings there was no effect of compressibility, that is, no effect of Mach number (the Mach number being the speed of flight divided by the speed of sound, a measure of compressibility)
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From page 247... ...
and decided that it did. Thus, the effective Mach number, on which the air forces depend, decreases continuously with increasing sweep; it follows that even at supersonic flight speeds the air forces can be made to have the advantageous properties found at low subsonic Mach numbers simply by introducing sufficient sweepback, in particular, that the enormously increased drag of conventional unswept wings at supersonic speeds can be reduced to subsonic levels.
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From page 248... ...
At the time of R.T.'s work no one in the United States appears to have been aware that the eminent German aerodynamicist Adolf Busemann had used the independence principle to examine the theoretical high-speed possibilities of sweep as one of a number of topics in his lecture to the Volta Congress in Rome in 1935. His idea received little notice perhaps because Busemann's thinking considered only supersonic flight speeds and sweep angles for which the effective Mach number remained supersonic -- speeds that seemed far beyond practical attainment at that time.
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From page 249... ...
. Another put the "area rule" for flight speeds near the speed of sound, which transforms the pressure-drag problem for a wing-body combination into that for an equivalent body of revolution, on a firm theoretical foundation and extended it to supersonic flight speeds (1956,1)
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From page 250... ...
Such adjustment is mechanically and structurally easier for an oblique wing with a single pivot atop the fuselage than for a conventional swept wing with its required pair of pivots, one on each side. Along with its potential aerodynamic and mechanical virtues, the oblique wing raised questions about stability and control and about aeroelastic deformation and hence structural design.
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From page 251... ...
R.T.'s interests following his formal retirement at Ames centered on the even more startling concept of the oblique flying wing. This consists simply of an oblique wing without fuselage or tail and large enough to carry its load internally.
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From page 252... ...
This range appears in papers shortly before and after his retirement * om Ames on such miscellaneous topics as the motion of ultralight aircraft in vertical gusts, the dive recovery of hang gliders, the aerodynamics of flapping wings, and the efficiency of small transport aircraft.
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From page 253... ...
marveled at how he arrived at his ideas, seemingly intuitively and frequently in terms of physical models and analogies. He could use highly sophisticated mathematics deductively when necessary, but he did so mostly to support his ideas and explore their consequences.
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From page 254... ...
He also went frequently (though not in his Ercoupe) to the annual Experimental Airplane Association Fly-In at Oshkosh, Wisconsin, where he gave occasional talks on airplane aerodynamics.
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From page 255... ...
national academies: the National Academy of Engineering in 1973 and the National Academy of Sciences in 1981. His many other honors included the Sylvanus Albert Reed Award of the institute of the Aeronautical Sciences in 1946, the Prandtl Ring of the Deutsch Gesellschaft fur Luft und Raumfahrt in 1978, the Langley Medal of the Smithsonian institution in 1981 (an award shared with such aviation notables as the Wright brothers and Charles Lindbergh)
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From page 256... ...
. he captivated a generation of students with fresh insights and new ways of looking at problems ranging from hang-glider dynamics and optimal bird flapping to supersonic aircraft." Most important for his various activities, he seemed to have a quiet confidence that he could accomplish whatever he set out to do—even if it was to make a fine violin.
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From page 257... ...
18:75-81. 1952 Theoretical determination of the minimum drag of airfoils at supersonic speeds J Aero.
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From page 258... ...
1959 Aerodynamic design for supersonic speeds. In Proceedings, International Congress in the Aeronautical Sciences.
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From page 259... ...
Princeton: Princeton University Press. 1991 The flying wing supersonic transport.
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