Multi-objective Optimization of Patterned Void Structures

点击翻译按钮获取中文摘要

Hot section components of gas turbine engines experience very high operating temperatures and severe thermal gradients. As a result, high stresses and strains develop within engine components, thereby limiting their life and reliability, as well as increasing engine repair and overhaul costs. Cooling air is generally used to reduce component temperature and thermal stresses. While effective, this strategy reduces the amount of air available for combustion, leading to incomplete combustion with higher NOx and CO emissions. In a recently concluded Engage project with Rolls-Royce, we reached to the conclusion that voids can be patterned in optimal shapes to reduce stress and strain in hot-section components, thereby increasing engine life. Whereas stress reduction is crucial, other aspects, such as cooling and damping, govern engine performance. As a natural extension of the Engage, this project focuses on the search of optimal void patterns that can reconcile concurrently the following performance metrics of the gas turbine: structural integrity, cooling, and damping, and be robust to variations emerging from the manufacturing process. To our knowledge, this work is novel and the first of this kind. It requires the use of analysis tools for air flow and stress, the formulation and solution of structural (size, shape and topology) optimization problems that can effectively handle multiple objectives, and the experimental validation of the results, each contributing to address the implementation of optimal cellular patterns in gas turbine engines. A successful outcome from this project will allow Rolls-Royce Canada to design engines with increased reliability while achieving increased efficiency and lower emissions. Furthermore the project will yield invaluable research insights (both fundamental and applied) in the fields of structural mechanics, topology and multi-objective optimization of patterned void structures and cellular materials at large, along with the training of highly qualified engineers, proficient in gas turbine technologies.