james reuther - Academia.edu (original) (raw)

Papers by james reuther

Research paper thumbnail of Sharp Technologies as Applied to a Crew Transfer Vehicle (CTV)

This viewgraph presentation reviews the efforts of Ames Research Center to develop Slender Hypers... more This viewgraph presentation reviews the efforts of Ames Research Center to develop Slender Hypersonic Aerothermodynamic Research Probes (SHARP) technologies as applied to the new Crew Transfer Vehicle (CTV). Amongst these technologies are ultra high temperature ceramics (UHTC). The results of Computational Fluid Dynamic simulations on prospective designs of the CTV are shown as well as wind tunnel test results.

Research paper thumbnail of The TPS Advanced Development Project for CEV

Research paper thumbnail of CFD Analysis and Design Optimization Using Parallel Computers

Some New Directions in Science on Computers, Sep 1, 1997

Research paper thumbnail of Control theory based airfoil design using the Euler equations

5th Symposium on Multidisciplinary Analysis and Optimization, 1994

Research paper thumbnail of Aerodynamic shape optimization of wing and wing-body configurations using control theory

33rd Aerospace Sciences Meeting and Exhibit, 1995

This paper describes the implementation of optimization techniques based on control theory for wi... more This paper describes the implementation of optimization techniques based on control theory for wing and wing-body design. In previous studies [18, 19,221 it wasshown that control theory could be used to devise an effective optimization procedure for airfoils and wings in which the shape and the surrounding body-fitted mesh are both generated analytically, and the control is the mapping function. Recently, the method has been implemented for both potential flows and flows governed by the Euler equations using an alternative formulation which employs numerically generated grids, so that it can more easily he extended to treat general configurations [34, 231. Here results are presented both for the optimization of a swept wing using an analytic mapping, and for the optimization of wing and wing-body configurations using a general mesh. " Nomenclature a spanwise scale factor A; Cartesian flux Jacobians A, 8, C metric terms b design variable b bandwidth of full Jacobian matrix B generic boundary of flowfield domain Bw wing surface boundary of flowfield domain 'Student Member AIAA t James S. McDomeU Distin-shed University Professor 'Copyright 01995 by the American Institute of Aeronau-.J of Aerospace Engineering, AIAA Fellow tics and Astronautics, lnc. All rights reserved BF B s C.

Research paper thumbnail of Aerodynamic shape optimization of complex aircraft configurations via an adjoint formulation

34th Aerospace Sciences Meeting and Exhibit, 1996

This work describes the implementation of optimization techniques based on control theory for com... more This work describes the implementation of optimization techniques based on control theory for complex aircraft configurations. Here control theory is employed to derive the adjoint differential equations, the solution of which allows for a drastic reduction in computational costs over previous design methods. Design formulations for both potential flows and flows governed by the Euler equations have been demonstrated, showing that such methods can be devised for various governing equations. The method uses the Euler equations to treat complete aircraft configurations via a new multiblock implementation. New elements include a multiblock-multigrid flow solver, a multiblock-multigrid adjoint solver, and a multiblock mesh perturbation scheme. Two design examples are presented in which the new method is used for the wing redesign of a transonic business jet.

Research paper thumbnail of An efficient multiblock method for aerodynamic analysis and design on distributed memory systems

13th Computational Fluid Dynamics Conference, 1997

Research paper thumbnail of Aerodynamic Shape Optimization for Supersonic Aircraft

32nd AIAA Fluid Dynamics Conference and Exhibit, 2002

Research paper thumbnail of The Advanced Engineering Environment (AEE) Project for NASA's Next Generation Launch Technologies (NGLT) Program

42nd AIAA Aerospace Sciences Meeting and Exhibit, 2004

Research paper thumbnail of Complete Configuration Aero-Structural Optimization Using a Coupled Sensitivity Analysis Method

9th AIAA/ISSMO Symposium on Multidisciplinary Analysis and Optimization, 2002

Public reporting burden for the collection of information is estimated to average 1 hour per resp... more Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.

Research paper thumbnail of pyMDO: A Framework for High-Fidelity Multi-Disciplinary Optimization

10th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, 2004

Research paper thumbnail of A coupled aero-structural optimization method for complete aircraft configurations

37th Aerospace Sciences Meeting and Exhibit, 1999

Research paper thumbnail of High-Fidelity Aero-Structural Design Using a Parametric CAD-Based Model

16th AIAA Computational Fluid Dynamics Conference, 2003

Research paper thumbnail of High-Fidelity Aerostructural Design Optimization of a Supersonic Business Jet

Journal of Aircraft, 2004

This paper focuses on the demonstration of an integrated aerostructural method for the design of ... more This paper focuses on the demonstration of an integrated aerostructural method for the design of aerospace vehicles. Both aerodynamics and structures are represented using high-fidelity models such as the Euler equations for the aerodynamics and a detailed finite element model for the primary structure. The aerodynamic outer-mold line and a structure of fixed topology are parameterized using a large number of design variables. The aerostructural sensitivities of aerodynamic and structural cost functions with respect to both outer-mold line shape and structural variables are computed using an accurate and efficient coupled-adjoint procedure. Kreisselmeier-Steinhauser functions are used to reduce the number of structural constraints in the problem. Results of the aerodynamic shape and structural optimization of a natural laminar-flow supersonic business jet are presented together with an assessment of the accuracy of the sensitivity information obtained using the coupled-adjoint procedure.

Research paper thumbnail of Aero-structural wing design optimization using high-fidelity sensitivity analysis

Abstract: This paper develops and implements a framework for the computation of coupled aero-stru... more Abstract: This paper develops and implements a framework for the computation of coupled aero-structural sensitivities which are required for the design of aircraft where aeroelastic interactions are significant. All aero-structural sensitivities are computed using high-fidelity models of both the aerodynamics and the structure of the wing with a coupled-adjoint approach that uses single discipline sensitivity information to calculate the sensitivities of the coupled system. The sensitivities of drag with respect to a set of shape design variables ...

Research paper thumbnail of Constrained Multipoint Aerodynamic Shape Optimization Using an Adjoint Formulation and Parallel Computers, Part 1

Journal of Aircraft, 1999

Research paper thumbnail of Predicting Boundary-Layer Transition on Space-Shuttle Re-Entry

The BLT Prediction Tool ("BLT" signifies "Boundary Layer Transition") is prov... more The BLT Prediction Tool ("BLT" signifies "Boundary Layer Transition") is provided as part of the Damage Assessment Team analysis package, which is utilized for analyzing local aerothermodynamics environments of damaged or repaired space-shuttle thermal protection tiles. Such analyses are helpful in deciding whether to repair launch-induced damage before re-entering the terrestrial atmosphere.

Research paper thumbnail of Low Speed Aerodynamics and Landing Characteristics of Sharp-Class Crew Transfer Vehicle Concepts

A study is performed examining the low speed aerodynamic performance and landing characteristics ... more A study is performed examining the low speed aerodynamic performance and landing characteristics of a preliminary new Crew Transfer Vehicle (CTV). The new vehicle employs a sharp nose with UltraHigh Temperature Ceramic (UHTC) thermal protection instead of the blunt nose of ...

Research paper thumbnail of Control theory based airfoil design for potential flow and a finite volume discretization

32nd Aerospace Sciences Meeting and Exhibit

This paper describes the implementation of optimization techniques based on control theory for ai... more This paper describes the implementation of optimization techniques based on control theory for airfoil design. In previous studies [6, 71 it was shown that control theory could be used to devise an effective optimization procedure for two-dimensional profiles in which the shape is determined by a conformal transformation from a unit circle, and the control is the mapping function. The goal of our present work is to develop a method which does not depend on conformal mapping, so that it can be extended to treat three-dimensional problems. Therefore, we have developed a method which can address arbitrary geometric shapes through the use of a finite volume method to discretize the potential flow equation. Here the control law serves to provide computationally inexpensive gradient information to a standard numerical optimization method. Results are presented, where both target speed distributions and minimum drag are used as objective functions.-Nomenclature A,, grid transformation coefficients b design variable B generic co-state variable c speed of sound C C d coefficient of drag Ci coefficient of lift C, coefficient of pressure bounding surface of flowfield domain on airfoil 'Graduate Student, Student Memher AIAA tJames S. McDomeU Distinguished University Professor Copyright 01994 hy the American Institute of Aeronau-of Aerospace Engineering, AIAA Fellow tics and Astronautics, hc. All rights reserved W C; d

Research paper thumbnail of A Coupled-Adjoint Sensitivity Analysis Method for High-Fidelity Aero-Structural Design

This paper presents an adjoint method for sensitivity analysis that is used in an aero-structural... more This paper presents an adjoint method for sensitivity analysis that is used in an aero-structural aircraft design framework. The aero-structural analysis uses high-fidelity models of both the aerodynamics and the structures. Aero-structural sensitivities are computed using a coupled-adjoint approach that is based on previously developed single discipline sensitivity analysis. Alternative strategies for coupled sensitivity analysis are also discussed. The aircraft geometry and a structure of fixed topology are parameterized using a large number of design variables. The aero-structural sensitivities of aerodynamic and structural functions with respect to these design variables are computed and compared with results given by the complex-step derivative approximation. The coupled-adjoint procedure is shown to yield very accurate sensitivities and to be computationally efficient, making high-fidelity aero-structural design feasible for problems with thousands of design variables.

Research paper thumbnail of Sharp Technologies as Applied to a Crew Transfer Vehicle (CTV)

This viewgraph presentation reviews the efforts of Ames Research Center to develop Slender Hypers... more This viewgraph presentation reviews the efforts of Ames Research Center to develop Slender Hypersonic Aerothermodynamic Research Probes (SHARP) technologies as applied to the new Crew Transfer Vehicle (CTV). Amongst these technologies are ultra high temperature ceramics (UHTC). The results of Computational Fluid Dynamic simulations on prospective designs of the CTV are shown as well as wind tunnel test results.

Research paper thumbnail of The TPS Advanced Development Project for CEV

Research paper thumbnail of CFD Analysis and Design Optimization Using Parallel Computers

Some New Directions in Science on Computers, Sep 1, 1997

Research paper thumbnail of Control theory based airfoil design using the Euler equations

5th Symposium on Multidisciplinary Analysis and Optimization, 1994

Research paper thumbnail of Aerodynamic shape optimization of wing and wing-body configurations using control theory

33rd Aerospace Sciences Meeting and Exhibit, 1995

This paper describes the implementation of optimization techniques based on control theory for wi... more This paper describes the implementation of optimization techniques based on control theory for wing and wing-body design. In previous studies [18, 19,221 it wasshown that control theory could be used to devise an effective optimization procedure for airfoils and wings in which the shape and the surrounding body-fitted mesh are both generated analytically, and the control is the mapping function. Recently, the method has been implemented for both potential flows and flows governed by the Euler equations using an alternative formulation which employs numerically generated grids, so that it can more easily he extended to treat general configurations [34, 231. Here results are presented both for the optimization of a swept wing using an analytic mapping, and for the optimization of wing and wing-body configurations using a general mesh. " Nomenclature a spanwise scale factor A; Cartesian flux Jacobians A, 8, C metric terms b design variable b bandwidth of full Jacobian matrix B generic boundary of flowfield domain Bw wing surface boundary of flowfield domain 'Student Member AIAA t James S. McDomeU Distin-shed University Professor 'Copyright 01995 by the American Institute of Aeronau-.J of Aerospace Engineering, AIAA Fellow tics and Astronautics, lnc. All rights reserved BF B s C.

Research paper thumbnail of Aerodynamic shape optimization of complex aircraft configurations via an adjoint formulation

34th Aerospace Sciences Meeting and Exhibit, 1996

This work describes the implementation of optimization techniques based on control theory for com... more This work describes the implementation of optimization techniques based on control theory for complex aircraft configurations. Here control theory is employed to derive the adjoint differential equations, the solution of which allows for a drastic reduction in computational costs over previous design methods. Design formulations for both potential flows and flows governed by the Euler equations have been demonstrated, showing that such methods can be devised for various governing equations. The method uses the Euler equations to treat complete aircraft configurations via a new multiblock implementation. New elements include a multiblock-multigrid flow solver, a multiblock-multigrid adjoint solver, and a multiblock mesh perturbation scheme. Two design examples are presented in which the new method is used for the wing redesign of a transonic business jet.

Research paper thumbnail of An efficient multiblock method for aerodynamic analysis and design on distributed memory systems

13th Computational Fluid Dynamics Conference, 1997

Research paper thumbnail of Aerodynamic Shape Optimization for Supersonic Aircraft

32nd AIAA Fluid Dynamics Conference and Exhibit, 2002

Research paper thumbnail of The Advanced Engineering Environment (AEE) Project for NASA's Next Generation Launch Technologies (NGLT) Program

42nd AIAA Aerospace Sciences Meeting and Exhibit, 2004

Research paper thumbnail of Complete Configuration Aero-Structural Optimization Using a Coupled Sensitivity Analysis Method

9th AIAA/ISSMO Symposium on Multidisciplinary Analysis and Optimization, 2002

Public reporting burden for the collection of information is estimated to average 1 hour per resp... more Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.

Research paper thumbnail of pyMDO: A Framework for High-Fidelity Multi-Disciplinary Optimization

10th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, 2004

Research paper thumbnail of A coupled aero-structural optimization method for complete aircraft configurations

37th Aerospace Sciences Meeting and Exhibit, 1999

Research paper thumbnail of High-Fidelity Aero-Structural Design Using a Parametric CAD-Based Model

16th AIAA Computational Fluid Dynamics Conference, 2003

Research paper thumbnail of High-Fidelity Aerostructural Design Optimization of a Supersonic Business Jet

Journal of Aircraft, 2004

This paper focuses on the demonstration of an integrated aerostructural method for the design of ... more This paper focuses on the demonstration of an integrated aerostructural method for the design of aerospace vehicles. Both aerodynamics and structures are represented using high-fidelity models such as the Euler equations for the aerodynamics and a detailed finite element model for the primary structure. The aerodynamic outer-mold line and a structure of fixed topology are parameterized using a large number of design variables. The aerostructural sensitivities of aerodynamic and structural cost functions with respect to both outer-mold line shape and structural variables are computed using an accurate and efficient coupled-adjoint procedure. Kreisselmeier-Steinhauser functions are used to reduce the number of structural constraints in the problem. Results of the aerodynamic shape and structural optimization of a natural laminar-flow supersonic business jet are presented together with an assessment of the accuracy of the sensitivity information obtained using the coupled-adjoint procedure.

Research paper thumbnail of Aero-structural wing design optimization using high-fidelity sensitivity analysis

Abstract: This paper develops and implements a framework for the computation of coupled aero-stru... more Abstract: This paper develops and implements a framework for the computation of coupled aero-structural sensitivities which are required for the design of aircraft where aeroelastic interactions are significant. All aero-structural sensitivities are computed using high-fidelity models of both the aerodynamics and the structure of the wing with a coupled-adjoint approach that uses single discipline sensitivity information to calculate the sensitivities of the coupled system. The sensitivities of drag with respect to a set of shape design variables ...

Research paper thumbnail of Constrained Multipoint Aerodynamic Shape Optimization Using an Adjoint Formulation and Parallel Computers, Part 1

Journal of Aircraft, 1999

Research paper thumbnail of Predicting Boundary-Layer Transition on Space-Shuttle Re-Entry

The BLT Prediction Tool ("BLT" signifies "Boundary Layer Transition") is prov... more The BLT Prediction Tool ("BLT" signifies "Boundary Layer Transition") is provided as part of the Damage Assessment Team analysis package, which is utilized for analyzing local aerothermodynamics environments of damaged or repaired space-shuttle thermal protection tiles. Such analyses are helpful in deciding whether to repair launch-induced damage before re-entering the terrestrial atmosphere.

Research paper thumbnail of Low Speed Aerodynamics and Landing Characteristics of Sharp-Class Crew Transfer Vehicle Concepts

A study is performed examining the low speed aerodynamic performance and landing characteristics ... more A study is performed examining the low speed aerodynamic performance and landing characteristics of a preliminary new Crew Transfer Vehicle (CTV). The new vehicle employs a sharp nose with UltraHigh Temperature Ceramic (UHTC) thermal protection instead of the blunt nose of ...

Research paper thumbnail of Control theory based airfoil design for potential flow and a finite volume discretization

32nd Aerospace Sciences Meeting and Exhibit

This paper describes the implementation of optimization techniques based on control theory for ai... more This paper describes the implementation of optimization techniques based on control theory for airfoil design. In previous studies [6, 71 it was shown that control theory could be used to devise an effective optimization procedure for two-dimensional profiles in which the shape is determined by a conformal transformation from a unit circle, and the control is the mapping function. The goal of our present work is to develop a method which does not depend on conformal mapping, so that it can be extended to treat three-dimensional problems. Therefore, we have developed a method which can address arbitrary geometric shapes through the use of a finite volume method to discretize the potential flow equation. Here the control law serves to provide computationally inexpensive gradient information to a standard numerical optimization method. Results are presented, where both target speed distributions and minimum drag are used as objective functions.-Nomenclature A,, grid transformation coefficients b design variable B generic co-state variable c speed of sound C C d coefficient of drag Ci coefficient of lift C, coefficient of pressure bounding surface of flowfield domain on airfoil 'Graduate Student, Student Memher AIAA tJames S. McDomeU Distinguished University Professor Copyright 01994 hy the American Institute of Aeronau-of Aerospace Engineering, AIAA Fellow tics and Astronautics, hc. All rights reserved W C; d

Research paper thumbnail of A Coupled-Adjoint Sensitivity Analysis Method for High-Fidelity Aero-Structural Design

This paper presents an adjoint method for sensitivity analysis that is used in an aero-structural... more This paper presents an adjoint method for sensitivity analysis that is used in an aero-structural aircraft design framework. The aero-structural analysis uses high-fidelity models of both the aerodynamics and the structures. Aero-structural sensitivities are computed using a coupled-adjoint approach that is based on previously developed single discipline sensitivity analysis. Alternative strategies for coupled sensitivity analysis are also discussed. The aircraft geometry and a structure of fixed topology are parameterized using a large number of design variables. The aero-structural sensitivities of aerodynamic and structural functions with respect to these design variables are computed and compared with results given by the complex-step derivative approximation. The coupled-adjoint procedure is shown to yield very accurate sensitivities and to be computationally efficient, making high-fidelity aero-structural design feasible for problems with thousands of design variables.