Development of an Automated Preliminary Combustion Chamber Design Tool

Abstract

The preliminary design of a new combustion chamber requires the combination of many elements of know-how in terms of combustor design rules, aerothermal calculations and preliminary design tools. To use this knowledge more efficiently pre-competitive work on an automated knowledge-based combustor design methodology is done within the European project INTELLECT D.M. (Integrated Lean Low Emission Combustor Design Methodology) in order to set up a KBE (Knowledge Based Engineering) system. In the method presented here, the rules and calculation routines are implemented into an automated preliminary design system using an Excel-driven database to generate a parametric Unigraphics CAD model. The utilized design rules represent state-of-the-art combustor design and will be extended later by lean combustion design rules, which are currently developed within INTELLECT D.M.. The database contains all design parameters and rules to provide CAD, CFD and optimization tools with the required information. Based on a set of performance parameters the system automatically generates the parametric geometry of a combustor containing the liners with cooling devices (optionally Z-ring or effusion cooling) and mixing holes, heat shield, cowl, casings and (pre)diffusor. To estimate the required cooling air, one-dimensional heat transfer equations including convection, radiation and conduction are solved. The generated CAD model visualizes the calculated combustor geometry and forms the basis for an automated CFD mesh generation utilizing the grid generator ICEM CFD.