2021-03 Pearcey Newby and the Vulcan V2.Pdf
Journal of Aeronautical History Paper 2021/03 Pearcey, Newby, and the Vulcan S C Liddle Vulcan to the Sky Trust ABSTRACT In 1955 flight testing of the prototype Avro Vulcan showed that the aircraft’s buffet boundary was unacceptably close to the design cruise condition. The Vulcan’s status as one of the two definitive carrier aircraft for Britain’s independent nuclear deterrent meant that a strong connection existed between the manufacturer and appropriate governmental research institutions, in this case the Royal Aircraft Establishment (RAE) and the National Physical Laboratory (NPL). A solution was rapidly implemented using an extended and drooped wing leading edge, designed and high-speed wind-tunnel tested by K W Newby of RAE, subsequently being fitted to the scaled test version of the Vulcan, the Avro 707A. Newby’s aerodynamic solution exploited a leading edge supersonic-expansion, isentropic compression* effect that was being investigated at the time by researchers at NPL, including H H Pearcey. The latter would come to be associated with this ‘peaky’ pressure distribution and would later credit the Vulcan implementation as a key validation of the concept, which would soon after be used to improve the cruise efficiency of early British jet transports such as the Trident, VC10, and BAC 1-11. In turn, these concepts were exploited further in the Hawker-Siddeley design for the A300B, ultimately the basis of Britain’s status as the centre of excellence for wing design in Airbus. Abbreviations BS Bristol Siddeley L Lift D Drag M Mach number CL Lift Coefficient NPL National Physical Laboratory Cp Pressure coefficient RAE Royal Aircraft Establishment Cp.te Pressure coefficient at trailing edge RAF Royal Air Force c Chord Re Reynolds number G Load factor t Thickness HS Hawker Siddeley WT Wind tunnel HP Handley Page α Angle of Attack When the airflow past an aerofoil accelerates its pressure and temperature drop, and vice versa.
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