A CAD-Based Blade Geometry Model for Turbomachinery Aero Design Systems

Abstract

A CAD-centric approach for constructing and managing the blade geometry in turbomachinery aero design systems is presented in this paper. Central to the approach are a flexible CAD-based parametric blade model definition and a set of CAD-neutral interfaces which enable construction and manipulation of the blade solid model directly inside the CAD system’s geometry kernel. A bottleneck of transferring geometry data passively via a file-based method is thus eliminated, and a seamless integration between the CAD system, aero design system, and the larger design environment can be achieved. A single consistent CAD-based blade model is available at all stages of the aero design process, forming the basis for coupling the aero design system to the larger multi-disciplinary design environment. The blade model construction is fully parameterized so that geometry updates can be accurately controlled via parameter changes, and geometric sensitivities of the model can be easily calculated for multidisciplinary interaction and design optimization. A clear separation of the parameters that control the three-dimensional shape of the blade (such as lean and sweep) from the parameters that control the elemental profile shape allows any blade profile family or shape definition to be utilized. The blade model definition, construction interface, and implementation approach are described. Applications illustrating solid model construction, parametric modification and sensitivity calculation, which are key requirements for automated aerodynamic shape design, are presented.