Annals of the Assembly for International Heat Transfer Conference 13

ISBN 1-56700-225-0 / CD 1-56700-226-9

Year 2006

H. Kim
University of Bath, Bath, United Kingdom

C. T. Fenton
University of Bath, Bath, United Kingdom

This paper introduces a 3D topology optimisation strategy for multi-criteria of thermoelasticity and heat transfer. The optimisation method is based on evolutionary topology optimisation, where recent research has established that its simple concept of slowly removing low stressed material reliably optimises a design towards the intuitive optimum of a fully-stressed design.
The optimisation problem considered is design of structures for a high temperature environment, such as turbine discs. Turbine discs can experience a wide range of temperature variations and the transient response to the thermal loads induces high thermal strain leading to reduced fatigue life. It is thus proposed that reducing variations in the heat flux field in a design would have a significant benefit in the fatigue life.
The optimisation criteria are therefore, to achieve the fully stressed iso-flux design. This is considered as a multi-criteria optimisation problem where both von Mises stress and heat flux are used as local sensitivities to modify the structural design. The proposed optimisation strategy introduces a sensitivity formulation that appropriately normalises and combines the two sensitivities. This is implemented in three-dimensions with a suitable chequerboard filtering technique.
The multi-criteria optimisation strategy is then applied to optimisation of a turbine disc design. The results reveal the danger of the common weighting factor approach to multi-criteria optimisation and the solution may have a significant dependency on the initial design, due to the ill-posedness of the optimisation problem. The paper demonstrates that a heuristic optimisation approach may be applied to ill-posed multi-criteria problems with conflicting criteria for improving designs.

EQP-15 pages DOI: 10.1615/IHTC13.p22.150 Download article

Article price - $35.00

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