Parametric Turbine Blade Development Model

Abstract

Gas turbine blades operate in an extremely hostile environment; their design is a complex and challenging task involving high requirements on aerodynamics, cooling, mechanical integrity and manufacturing. As well, in industry, intense competition creates pressure to continually upgrade and innovate products. One of the first motivations in any product development is to shorten the design time of the product lifecycle. The mechanical design has to take into account all the constraints imposed by the demanding boundaries, thus the CAD system plays a key role in achieving the targets. The early design process consists of three main steps: modelling, analysis and optimization. The modelling stage requires many iteration cycles until a stable design is achieved, considering all of the different solutions that exist for any given problem. The analysis stage shows which designs are feasible. Optimization requires many iterations to achieve the desired goals, so this final step includes both of the previous stages, since it uses the results from analysis to drive the design. Thus, the need for robust and parametric models on the development phase of the project becomes apparent. Development models are the models created on the early design phases of the project. They are responsible to define the basic geometry and the features that will be included in the final blade model. They are involved in many iterations cycles until a stable design is achieved. When the final development blade design is achieved, the manufacturing blade can be modelled. The manufacturing model is based on the development model but including seals and cooling features depreciated previously for analysis reasons. Until now these models were created but not managed 12 We reserve all rights in this document and in the information contained therein. Reproduction, use or disclosure to third parties without express authority is strictly forbidden. © ALSTOM (Switzerland) Ltd 2011. Form: FM 0501 en / Ae.02 / 01-09-07 / GTSQ afterwards. Thus, these models were not available as history of the product. The goal is to create a robust parametric development model and integrate it into the design process, taking advantage of the PLM software capabilities. The CAD system is becoming pivotal for the development process, playing an integration role, where the different disciplines link in by either providing geometry or by acting as a consumer. Further downstream, a seamless chain from first sketch to manufacturing models helps to reduce turnaround times and guarantees model consistency thus keeping an adequate audit trail. The whole process is embedded in the corporate PLM chain. Thus, this thesis proposes a modeling structure for gas turbine development blade models in CATIA v5 including parametric CAD features. It has been elaborated in cooperation between Eidgenössische Technische Hochschule Zürich (ETH Zurich) and ALSTOM (Switzerland) Ltd. More specifically in ALSTOM Power group, on Gas Sector inside the Turbine Design department.