Scientific and Technical Aerospace Reports Volume 38 July 28, 2000

A long tradition of aerodynamic design of combat vehicles shows that the expression of the targets and the constraints in the
design are always difficult to select. Present long iteration processes hide such variable target/constraints continuous reassessment.
Every processes of design unable to have flexibility in target/constraint handling is unusable. Fortunately, the geometrical
constraints are now better handled in new CAD software with features modeling. The present development of new constrained
features modeling will be described from its basic expression to the more complex and variable topology configuration. Fitting
the optimization process to the physics of multidisciplinary constraints may not be as easy as for geometry. It is proposed to select
a family of constrained variations of geometry, each able to cope with a specific physical optimization and to generate a multiprojection
of the multi-constrained operators. Some conceptual examples of such processes will be presented in the case of aeroelastic
design electromagnetic design and actively controlled configurations with variable geometry for improvement of flow control.
The specific domains of use of deterministic and stochastic (genetic) algorithm and of self-adaptation by training (neural network)
will be assessed. New strategies will be proposed for sharing the work of optimization between different companies cooperating
to the design of advanced aerospace vehicles.
Author
Aerodynamics; Design Analysis; Active Control; Aerospace Vehicles; Complex Variables; Computer Aided Design
20000061429 British Aerospace Public Ltd. Co., Military Aircraft and Aerostructures, Warton, UK
Aspects of Aerodynamic Optimisation for Military Aircraft Design
Probert, B., British Aerospace Public Ltd. Co., UK; Aerodynamic Design and Optimisation of Flight Vehicles in a Concurrent
Multi-Disciplinary Environment; June 2000, pp. 11-1 - 11-12; In English; See also 20000061419; Copyright Waived; Avail:
CASI; A03, Hardcopy
The paper considers the role of various optimisation strategies in the aerodynamic design of military combat aircraft. The
multi - design point targets of military aircraft implies that the final product must achieve a carefully judged balance between,
often conflicting, requirements. The current established way of working to achieve this ”balance” is first reviewed including the
use of rule based procedures, the application of linearised CFD codes in both direct and inverse/optimisation modes, and the role
of initial experimental data leading on to more detailed CFD work and experimental verification. Practical examples are given
relating to the design of various projects including the Experimental Aircraft Programme (EAP), which was the forerunner of
Eurotighter. The need for improvements is identified, being primarily brought about by considerations of affordability and
reduced design cycle time and also by the challenge posed from novel configurations to met low observability requirements. The
means of achieving these improvements is discussed, and these imply the development of Multi Disciplinary Optimisation (MDO)
in a wide sense. Numerical optimisation experience is reviewed but it is strongly emphasised that there is a need for rapid experimental
input to the configuration design choice programme. Means of achieving this are discussed and examples given. The high
incidence requirements have a strong impact on CFD developments and areas of improvement are identified. This leads to a proposed
new way of working implying a much stronger interaction between the initial and detailed design phases of aircraft design.
Author
Aircraft Design; Optimization; Aerodynamics; Computational Fluid Dynamics
20000061430 Defence Evaluation Research Agency, Aerodynamics and Hydrodynamics Centre, Farnborough, UK
Progress Towards a Multi-disciplinary Analysis and Optimisation Capability for Air Vehicle Assessment and Design: A
UK Research Establishment View
Lovell, David, Defence Evaluation Research Agency, UK; Bartholomew, Peter, Defence Evaluation Research Agency, UK; Aerodynamic
Design and Optimisation of Flight Vehicles in a Concurrent Multi-Disciplinary Environment; June 2000, pp. 12-1 -
12-11; In English; See also 20000061419; Copyright Waived; Avail: CASI; A03, Hardcopy
This paper considers progress towards establishing a Multi-disciplinary Design Optimisation (MDO) capability for assessment
and design. Some basic questions are posed and answered on the basis of experience gained by DERA as a result of participation
in a series of recent National and International projects undertaken in partnership with UK and European industry and
government research agencies. Issues addressed include the definition of MDO: its function within concurrent engineering: the
role of product models; the definition and execution of the MD0 process under users control; the use of trade-off studies for
requirements capture: and the degree to which MD0 can support detailed design work. The need for the adoption of standards in
the definition of the product model is highlighted.
Author
Design Analysis; Optimization; Aircraft Design
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