Performance and Stability Analysis of a Shrouded-Fan Unmanned Aerial Vehicle

This paper deals with the estimation of the performance and stability for a shrouded-fan unmanned rotorcraft whose mission profile also prescribes the flight in ground effect. The not so simple estimation of the aerodynamic coefficients and of the thrust in the various situations makes the performance calculation and the stability analysis difficult tasks. This is because of the strong interaction between the fan flow and shroud that causes quite different flow structures about the airframe depending on flight conditions. A further difficulty is related to the ground effect which produces substantial modifications in the rotor thrust and aerodynamic coefficients. To evaluate performance and stability, two models have been developed. One determines the aerodynamic coefficients of the shroud, whereas the other one calculates thrust and moment of the rotors system. Both models take into account the mutual interference between fan flow and fuselage and ground effect. Performance and stability are then discussed with reference to significant flight conditions.

[1]  D. Peters,et al.  Ground effect aerodynamics of lifting rotors hovering above inclined ground plane , 1999 .

[2]  Barnes W. McCormick,et al.  Aerodynamics of V/STOL flight , 1967 .

[3]  A. R. Kriebel,et al.  Theoretical stability derivatives for a ducted propeller , 1964 .

[4]  R. J. Margason,et al.  Vortex-lattice FORTRAN program for estimating subsonic aerodynamic characteristics of complex planforms , 1971 .

[5]  J. Gordon Leishman,et al.  Principles of Helicopter Aerodynamics , 2000 .

[6]  Kirill V. Rozhdestvensky.  Aerodynamics of a Lifting System in Extreme Ground Effect , 2000 .

[7]  Douglas A. Wardwell,et al.  Single Jet-Induced Effects on Small-Scale Hover Data in Ground Effect , 1997 .

[8]  Nicola de Divitiis,et al.  Performance and Stability of a Winged Vehicle in Ground Effect , 2009, 0912.3355.

[9]  John Horlock.  Actuator disk theory , 1978 .

[10]  D. A. Peters.  UNSTEADY AERODYNAMICS OF HELICOPTER ROTOR HOVERING IN DYNAMIC GROUND EFFECT , 1998 .

[11]  Frank L. Lewis,et al.  Aircraft Control and Simulation , 1992 .

[12]  Giulio Avanzini,et al.  Performance and stability of ducted-fan uninhabited aerial vehicle model , 2003 .

[13]  James S. Hayden,et al.  The Effect Of The Ground On Helicopter Hovering Power Required , 1976 .

[14]  D. Peters,et al.  Dynamic inflow modeling for simulation of a helicopter operating in ground effect , 1999 .

[15]  Kirill V. Rozhdestvensky.  The Aerodynamic Efficiency of a Wing in the Extreme Ground Effect , 2000 .

[16]  Giulio Avanzini,et al.  DESIGN OF A SHIPBOARD RECOVERY SYSTEM FOR A SHROUDED-FAN UAV , 2002 .

[17]  Bernard Etkin,et al.  Dynamics of Atmospheric Flight , 1972 .

[18]  David L. Kohlman.  Introduction to V/Stol Airplanes , 1981 .

[19]  Giulio Avanzini,et al.  Performance and Stability of a Ducted-Fan Uninhabited Aerial Vehicle , 2001 .

[20]  Norman K. Walker.  Influence of fan and ducting characteristics on the stability of ground effect machines , 1965 .

[21]  Nicola de Divitiis.  AERODYNAMIC MODELING AND PERFORMANCE ANALYSIS OF A SHROUDED-FAN UNMANNED AERIAL VEHICLE , 2002 .

[22]  G. D. Padfield,et al.  Helicopter Flight Dynamics: The Theory and Application of Flying Qualities and Simulation Modelling , 1995 .