Distributed Multidisciplinary Optimization of a Turbine Blade Regarding Performance, Reliability and Castability

Abstract

Modern aero-engine blades are optimized for high perfor- mance and long service life, but manufacturing requirements are not considered adequately during the design process. Thus, time- consuming, iterative re-designs become necessary until a pro- ducible component evolves. The multidisciplinary design opti- mization method presented in this paper addresses not only the aerodynamic efficiency and structural reliability of a new turbine blade, but also ensures the castability of the design and thereby accelerates the entire design process and reduces the time-to- production. Because real casting process simulations are very time-intensive, they were substituted by checks of experimentally and numerically validated geometrical constraints. Different engineering tools were assembled in a joint process chain using an integration framework, which manages and distributes the calculations and hence the workload in a shared network. Based on a preliminary design of a new turbine section, the selected initial low pressure turbine blade was neither castable nor reliable. The multidisciplinary optimization achieved a blade design that satisfies the requirements for a successful casting process, has a low failure probability and, although not as high as from a pure aerodynamic optimization, exhibits an efficiency improvement.