Advanced Modeling of Air- and Rotorcraft in a Multi-Disciplinary Environment at Early Design Stages

Abstract

The development of new air- and rotorcraft is very challenging. The design process is divided into three consecutive phases: Conceptual, preliminary and detailed design phase which combine various disciplines featuring different objectives, e.g. static versus crashworthy design. This paper focuses on the preliminary design stage. The aim of the presented work is a significant reduction of the time spent on model generation in a multi-disciplinary design environment. Moreover, automation is desired to couple different disciplines respectively tools, hence, reducing the error probability compared to manual processing. In the preliminary design phase a basic aircraft configuration which has been developed during the conceptual design serves to conduct trade studies. Objective of this stage is to enhance this basic aircraft configuration establishing an appropriate design that meets customer requirements including performance, weight, producibility and cost. This phase is of particular interest since the basic layout of the primary structure is defined here. Up to date, semi-analytical methods are commonly deployed during preliminary design. Though these methods lead to adequate results for major structural components, the evaluation of new aircraft configurations is still very challenging. One philosophy to improve preliminary design is to introduce the use of Finite Element Methods (FEM) at this early design stage benefitting from the constantly increasing computational power. To efficiently use FEM, fast and easy model generation methods are required. These methods also need to have the ability to cope with the generation of alternative design concepts (e.g. blended wing body, compound helicopter). In order to accelerate and simplify these modeling processes, the standardized data format CPACS (Common Parameterized Aircraft Configuration Schema) is used in combination with automated modeling tools. In this paper fully parameterized and automated process chains for the generation and analyses of air- and rotorcraft fuselage structures will be presented. The tools used within these processes will be introduced and basic applications will be shown to demonstrate the versatility, effectivity and the gain in efficiency. Applications range from initial distribution of primary structure over static analysis to evaluation of crashworthiness.