Aerodynamic Shape Optimization of Hovering Rotor Blades in Transonic Flow Using Unstructured Meshes

An aerodynamic shape optimization technique has been developed for helicopter rotor blades in hover based on a continuous adjoint method on unstructured meshes. For this purpose, the Euler flow solver and the adjoint sensitivity analysis were formulated on the rotating frame of reference. To handle the repeated evaluation of the flow solution and the sensitivity analysis efficiently, the flow and adjoint solvers were parallelized using a domain decomposition strategy. A solution-adaptive mesh refinement technique was adopted to better resolve the tip vortex. Applications were made to the aerodynamic shape optimization of the Caradonna-Tung rotor blade and the UH-60 rotor blade. The results showed that the present method is effective in determining optimum aerodynamic configurations of rotor blades in hover, which require minimum inviscid torque while maintaining the desired thrust level at transonic flight conditions.

[1]  Lakshmi N. Sankar,et al.  An Inverse Aerodynamic Design Method for Rotor Blades , 1995 .

[2]  M. J. Rimlinger,et al.  Constrained Multipoint Aerodynamic Shape Optimization Using an Adjoint Formulation and Parallel Computers , 1997 .

[3]  Antony Jameson,et al.  Computational Fluid Dynamics for Aerodynamic Design: Its Current and Future Impact , 2001 .

[4]  Oh Joon Kwon,et al.  Parallel 3-D Aerodynamic Shape Optimization on Unstructured Meshes , 2003 .

[5]  F. Blom.  Considerations on the spring analogy , 2000 .

[6]  William A. Crossley,et al.  Aerodynamic Shape Design for Rotor Airfoils via Genetic Algorithm , 1998 .

[7]  Jaime Peraire,et al.  Practical 3D aerodynamic design and optimization using unstructured meshes , 1996 .

[8]  R. M. Hicks,et al.  Wing Design by Numerical Optimization , 1977 .

[9]  Neal T. Frink,et al.  Upwind Scheme for Solving the Euler Equations on Unstructured Tetrahedral Meshes , 1992 .

[10]  George Karypis,et al.  Multilevel k-way Partitioning Scheme for Irregular Graphs , 1998, J. Parallel Distributed Comput..

[11]  Earl P. N. Duque,et al.  Flowfield analysis of modern helicopter rotors in hover by Navier-Stokes method , 1993 .

[12]  Timothy J. Barth,et al.  A Finite-Volume Euler Solver for Computing Rotary-Wing Aerodynamics on Unstructured Meshes , 1993 .

[13]  Lee,et al.  Aerodynamic Shape Optimization of Rotor Blades in Hover Using Unstructured Meshes , 2004 .

[14]  Kazuhiro Nakahashi,et al.  Flap-Deflection Optimization for Transonic Cruise Performance Improvement of Supersonic Transport Wing , 2001 .

[15]  M. J. Rimlinger,et al.  Constrained Multipoint Aerodynamic Shape Optimization Using an Adjoint Formulation and Parallel Computers , 1997 .

[16]  F. X. Caradonna,et al.  Experimental and Analytical Studies of a Model Helicopter Rotor in Hover , 1980 .

[17]  Oh Joon Kwon,et al.  Effect of Wake Adaptation on Rotor Hover Simulations Using Unstructured Meshes , 2001 .

[18]  Lee,et al.  Aerodynamic Design of Helicopter Rotor Blade in Forward Flight Using Response Surface Methodology , 2002 .

[19]  Siva Nadarajah,et al.  Convergence studies of the time accurate and non-linear frequency domain methods for optimum shape design , 2007 .