Accession Number : ADA517226

Title :   Optimum Design of a Compound Helicopter

Descriptive Note : Conference paper

Corporate Author : ARMY RESEARCH DEVELOPMENT AND ENGINEERING COMMAND MOFFETT FIELD CA AVIATION AEROFLIGHT DYNAMICS DIRECTORATE

Personal Author(s) : Yeo, Hyeonsoo ; Johnson, Wayne

PDF Url : ADA517226

Report Date : NOV 2006

Pagination or Media Count : 19

Abstract : A design and aeromechanics investigation was conducted for a 100,000-lb compound helicopter with a single main rotor, which is to cruise at 250 knots at 4000 ft/95 deg F condition. Performance, stability, and control analyses were conducted with the comprehensive rotorcraft analysis CAMRAD II. Wind tunnel test measurements of the performance of the H-34 and UH-1D rotors at high advance ratio were compared with calculations to assess the accuracy of the analysis for the design of a high speed helicopter. In general, good correlation was obtained when an increase of drag coefficients in the reverse flow region was implemented. An assessment of various design parameters (disk loading, blade loading, wing loading) on the performance of the compound helicopter was conducted. Lower wing loading (larger wing area) and higher blade loading (smaller blade chord) increased aircraft lift-to-drag ratio. However, disk loading has a small influence on aircraft lift-to-drag ratio. A rotor parametric study showed that most of the benefit of slowing the rotor occurred at the initial 20 to 30% reduction of the advancing blade tip Mach number. No stability issues were observed with the current design. Control derivatives did not change significantly with speed, but the did exhibit significant coupling.

Descriptors :   *AERODYNAMIC LOADING, *HELICOPTERS, *AERODYNAMIC STABILITY, *AIRCRAFT DESIGN, PERFORMANCE(ENGINEERING), HIGH VELOCITY, FINITE ELEMENT ANALYSIS, ACCURACY, HELICOPTER ROTORS, ROTOR BLADES(ROTARY WINGS), AEROELASTICITY, WIND TUNNEL TESTS, WAKE, NONLINEAR ANALYSIS, MACH NUMBER, FLUTTER, UTILITY AIRCRAFT, LIFT TO DRAG RATIO, TRIM(AERODYNAMICS), PARAMETRIC ANALYSIS, OPTIMIZATION, SYMPOSIA, MATHEMATICAL MODELS, VIBRATION

Subject Categories : Aerodynamics
      Helicopters

Distribution Statement : APPROVED FOR PUBLIC RELEASE