Effective adjoint approaches for computational fluid dynamics

Aerodynamic optimisation has become an indispensable component for any aerodynamic design over the past 60 years, with applications to aircraft, cars, trains, bridges, wind turbines, internal pipe flows, and cavities, among others, and is thus relevant in many facets of technology. With advancements in computational power, automated design optimisation procedures have become more competent, however, there is an ambiguity and bias throughout the literature with regards to relative performance of optimisation architectures and employed algorithms. This paper provides a well-balanced critical review of the dominant optimisation approaches that have been integrated with aerodynamic theory for the purpose of shape optimisation. A total of 229 papers, published in more than 120 journals and conference proceedings, have been classified into 6 different optimisation algorithm approaches. The material cited includes some of the most well-established authors and publications in the field of aerodynamic optimisation. This paper aims to eliminate bias toward certain algorithms by analysing the limitations, drawbacks, and the benefits of the most utilised optimisation approaches. This review provides comprehensive but straightforward insight for non-specialists and reference detailing the current state for specialist practitioners.

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State-of-the-art in aerodynamic shape optimisation methods

The aerodynamic shape optimization of wings in transonic flow is an inherently challenging problem. In addition to the high computational cost of solving the Reynolds-averaged Navier–Stokes equations, there is a complex interdependence between the cross-sectional shape, wave drag, and viscous effects. Furthermore, it is necessary to perform multipoint optimizations to ensure good performance for a range of flight conditions. The choice of which flight conditions should be considered in a multipoint optimization and how many of these should be considered is still not well understood. This paper addresses this issue by solving a series of seven benchmark optimizations developed by the AIAA Aerodynamic Optimization Discussion Group. These optimization cases include a single-point optimization, four three-point optimizations, a nine-point optimization, and a five-point optimization. The optimizations consist in minimizing the weighted drag coefficient subject to lift, moment, thickness, and volume constraints...

Multipoint Aerodynamic Shape Optimization Investigations of the Common Research Model Wing

Since its introduction, the NASA Common Research Model has proved a useful aerodynamic benchmark for predicting computational-fluid-dynamics-based drag and aerodynamic design optimization. The mode...

https://arc.aiaa.org/doi/pdf/10.2514/1.J056603

Benchmark Aerostructural Models for the Study of Transonic Aircraft Wings

A Jacobian-free approximate Newton–Krylov startup strategy for RANS simulations

On manufacturing constraints for tow-steered composite design optimization

High-fidelity aerostructural optimization of tow-steered composite wings

Composite materials have been playing a major role in modern aircraft design due to their high stiffness and strength to weight ratio. While the advantages of composite structures over their metallic counterparts is significant, it is possible to improve even further on the benefits offered by traditional composites through the use of novel composite manufacturing methods. One such method is automated fiber placement, whereby each layer of the laminate is laid up with spatially steered fiber orientations, as opposed to the traditional method, where the fiber direction is fixed for each layer. While these new “tow-steered” composites can potentially provide additional aeroelastic tailoring when applied aircraft wing design, it is not clear how to fully take advantage of this new design freedom. To address this, we use high-fidelity gradient-based aerostructural optimization to assess the relative performance of tow-steered composites compared to conventional composites, as well as aluminum. The aircraft configuration used in this work is a high aspect ratio variant of the Common Research Model (CRM). When comparing the optimal conventional composite and optimal aluminum designs we find an improvement of roughly 8.7% in fuel burn and a 39% reduction in structural weight. The tow-steered designs yield improvements of 0.4% in fuel burn and 10% in structural weight when compared to conventional composites.

High-fidelity multipoint aerostructural optimization of a high aspect ratio tow-steered composite wing

/pdf/high-fidelity-aerostructural-optimization-of-a-high-aspect-4zz46jkbnt.pdf

Timothy R. Brooks

Papers

Benchmark Aerostructural Models for the Study of Transonic Aircraft Wings

On manufacturing constraints for tow-steered composite design optimization

High-fidelity aerostructural optimization of tow-steered composite wings

High-fidelity multipoint aerostructural optimization of a high aspect ratio tow-steered composite wing

High-fidelity Aerostructural Optimization of a High Aspect Ratio Tow-steered Wing