Effect of leading edge cut on the aerodynamics of ram‐air parachutes

The effect of the configuration of leading edge cut on the aerodynamic performance of ram-air parachutes is studied via two-dimensional flow simulations. The incompressible Reynolds-averaged Navier-Stokes equations, in primitive variables, are solved using a stabilized finite-element formulation. The Baldwin-Lomax model is employed for turbulence closure. Flow past an LS(1) 0417 airfoil is investigated for various configurations of the leading edge cut and results are compared with those from a Clark-Y airfoil section. It is found that the configuration of the leading edge cut affects the lift-to-drag ratio (L/D) of the parachute very significantly. The L/D value has strong implications on the flight performance of the parachute. One particular configuration results in a L/D value that is in excess of 25 at 7.5° angle of attack. Results are presented for other angles of attack for this configuration.

[1]  S. Mittal,et al.  Incompressible flow computations with stabilized bilinear and linear equal-order-interpolation velocity-pressure elements , 1992 .

[2]  Sanjay Mittal,et al.  On the performance of high aspect ratio elements for incompressible flows , 2000 .

[3]  Richard Benney,et al.  Computational fluid-structure interaction model for parachute inflation , 1996 .

[4]  Hiroshi Higuchi,et al.  Parachute aerodynamics - An assessment of prediction capability , 1996 .

[5]  Y. Saad,et al.  GMRES: a generalized minimal residual algorithm for solving nonsymmetric linear systems , 1986 .

[6]  Sanjay Mittal,et al.  Prediction of Hysteresis Associated with the Static Stall of an Airfoil , 2000 .

[7]  S. Mittal,et al.  Computation of flows in supersonic wind-tunnels , 2001 .

[8]  W. D. Beasley,et al.  Low speed aerodynamic characteristics of a 17 percent thick airfoil section designed for general aviation applications , 1973 .

[9]  T. Chatzikonstantinou.  Numerical analysis of three-dimensional non rigid wings , 1989 .

[10]  G. L. C. Menard,et al.  A review of para-foil applications , 1970 .

[11]  Dimitri J. Mavriplis,et al.  TURBULENT FLOW CALCULATIONS USING UNSTRUCTURED AND ADAPTIVE MESHES , 1991 .

[12]  S. Mittal,et al.  Computation of two-dimensional flows past ram-air parachutes , 2001 .

[13]  J Lingard.  The Aerodynamics of Gliding Parachutes , 1986 .

[14]  W. K. Anderson,et al.  An implicit upwind algorithm for computing turbulent flows on unstructured grids , 1994 .

[15]  Yannis Kallinderis,et al.  Algebraic turbulence modeling for adaptive unstructured grids , 1992 .

[16]  Tayfun E. Tezduyar,et al.  Parallel finite element computation of the dynamics of large ram air parachutes , 1999 .