Aerofoil profile and sweep optimisation for a blended wing-body aircraft using a discrete adjoint method

Aerodynamic optimisations of a blended wing-body (BWB) aircraft are presented. A discrete adjoint solver is used to calculate efficiently the gradients, which makes it possible to optimise for a large number of design variables. The optimisations employ either a variable-fidelity method that combines low- and high-fidelity models or a direct sequential quadratic programming (SQP) method. Four Euler optimisations of a BWB aircraft are then presented. The optimisation is allowed to change a series of master sections defining the aircraft geometry as well as the sweep angle on the outer wing for two of the optimisations. Substantial improvements are obtained, not only in the Euler mode but also when the optimised geometries are evaluated using Reynolds-averaged Navier-Stokes solutions. Some interesting features of the optimised wing profiles are discussed.

[1]  Ning Qin,et al.  AERODYNAMIC STUDIES FOR BLENDED WING BODY AIRCRAFT , 2002 .

[2]  Oktay Baysal,et al.  Three-dimensional aerodynamic shape optimization using discrete sensitivity analysis , 1996 .

[3]  Kazuhiro Nakahashi,et al.  Aerodynamic design of a medium size blended-wing-body airplane , 2001 .

[4]  H. Lomax,et al.  Thin-layer approximation and algebraic model for separated turbulent flows , 1978 .

[5]  B. V. Leer,et al.  Towards the ultimate conservative difference scheme V. A second-order sequel to Godunov's method , 1979 .

[6]  Thierry Fol,et al.  Aerodynamic Optimization of Subsonic Flying Wing Configurations , 2002 .

[7]  Chun-Ho Sung,et al.  Aerodynamic design optimization using the Navier-Stokes and adjoint equations , 2001 .

[8]  A. Jameson,et al.  Aerodynamic Shape Optimization of Complex Aircraft Configurations via an Adjoint Formulation , 1996 .

[9]  Ning Qin,et al.  A matrix-free preconditioned Newton/GMRES method for unsteady Navier-Stokes solutions , 2000 .

[10]  O. Rho,et al.  Parallelized design optimization for transonic wings using aerodynamic sensitivity analysis , 2002 .

[11]  P. A. Newman,et al.  Approximation and Model Management in Aerodynamic Optimization with Variable-Fidelity Models , 2001 .

[12]  Ning Qin,et al.  Variable-fidelity aerodynamic optimization for turbulent flows using a discrete adjoint formulation , 2004 .

[13]  A. L. Tits,et al.  User's Guide for FSQP Version 3.0c: A FORTRAN Code for Solving Constrained Nonlinear (Minimax) Optimization Problems, Generating Iterates Satisfying All Inequality and Linear Constraints , 1992 .

[14]  H. Smith,et al.  COLLEGE OF AERONAUTICS BLENDED WING BODY DEVELOPMENT PROGRAMME , 2000 .

[15]  W. K. Anderson,et al.  First-Order Model Management With Variable-Fidelity Physics Applied to Multi-Element Airfoil Optimization , 2000 .

[16]  Armando Vavalle,et al.  Aerodynamic considerations of blended wing body aircraft , 2004 .

[17]  S. P. Spekreijse,et al.  Multigrid solution of the steady Euler equations , 1988 .

[18]  Kazuhiro Nakahashi,et al.  Discrete Adjoint Method for Unstructured Navier-Stokes Solver , 2005 .

[19]  Garret N. Vanderplaats,et al.  Numerical Optimization Techniques for Engineering Design: With Applications , 1984 .

[20]  Alan Morris.  MOB A European Distributed Multi-Disciplinary Design and Optimisation Project , 2002 .

[21]  Oh-Hyun Rho,et al.  Sensitivity Analysis for the Navier-Stokes Equations with Two-Equation Turbulence Models , 2001 .

[22]  Alan Le Moigne,et al.  A discrete Navier-Stokes adjoint method for aerodynamic optimisation of Blended Wing-Body configurations , 2002 .

[23]  S. Osher,et al.  Numerical experiments with the Osher upwind scheme for the Euler equations , 1982 .

[24]  Arthur C. Taylor,et al.  Observations on computational methodologies for use in large-scale, gradient-based, multidisciplinary design , 1992 .

[25]  S. Osher,et al.  Upwind difference schemes for hyperbolic systems of conservation laws , 1982 .

[26]  Philip E. Gill,et al.  Practical optimization , 1981 .

[27]  Oh Rho,et al.  Aerodynamic sensitivity analysis for turbulent flows on chimera overlaid grids , 2001 .

[28]  V. Schmitt,et al.  Pressure distributions on the ONERA M6 wing at transonic Mach numbers , 1979 .

[29]  Antony Jameson,et al.  Optimum aerodynamic design using the Navier-Stokes equations , 1997 .

[30]  B. V. Leer,et al.  Towards the ultimate conservative difference scheme III. Upstream-centered finite-difference schemes for ideal compressible flow , 1977 .

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

[32]  Sean Wakayama,et al.  BLENDED-WING-BODY OPTIMIZATION PROBLEM SETUP , 2000 .

[33]  Mohamed Gad-el-Hak,et al.  New Approach to Constrained Shape Optimization Using Genetic Algorithms , 1998 .

[34]  Armando Vavalle,et al.  Spanwise Lift Distribution for Blended Wing Body Aircraft. , 2005 .

[35]  M. Giles,et al.  Adjoint Code Developments Using the Exact Discrete Approach , 2001 .

[36]  A. L Bolsunovsky,et al.  Flying wing—problems and decisions , 2001 .

[37]  Antony Jameson,et al.  Aerodynamic design via control theory , 1988, J. Sci. Comput..

[38]  Gene Hou,et al.  First- and Second-Order Aerodynamic Sensitivity Derivatives via Automatic Differentiation with Incremental Iterative Methods , 1996 .

[39]  W. K. Anderson,et al.  Recent improvements in aerodynamic design optimization on unstructured meshes , 2001 .

[40]  P. A. Newman,et al.  An Approximately Factored Incremental Strategy for Calculating Consistent Discrete Aerodynamic Sensitivity Derivatives , 1992 .

[41]  P. A. Newman,et al.  Optimization with variable-fidelity models applied to wing design , 1999 .

[42]  R. H. Liebeck,et al.  Design of the Blended Wing Body Subsonic Transport , 2002 .

[43]  A. Jameson,et al.  Optimum Aerodynamic Design Using the Navier–Stokes Equations , 1997 .

[44]  Robert Liebeck,et al.  BLENDED-WING-BODY SUBSONIC COMMERCIAL TRANSPORT , 1998 .

[45]  Scott Shaw.  Numerical study of the unsteady aerodynamics of helicopter rotor aerofoils , 1999 .

[46]  Sean Wakayama,et al.  Optimization of High-Subsonic Blended-Wing-Body Configurations , 2002 .

[47]  Mark Page,et al.  Blended Wing Body analysis and design , 1997 .