Integrated Fluid Network-Thermomechanical Approach for the Coupled Analysis of a Jet Engine

The present investigation aims at taking the existing interactions between secondary air properties (temperatures, pressures and mass flow rates) and material thermomechanical properties (temperature repartition and displacements) into consideration in a robust and modular analysis tool, combining air system, thermal and mechanical analysis. For air system calculations, a one-dimensional network representation is used. This network, the basic topology of which is presented in the paper, is coupled within a thermomechanical finite element model of the engine secondary air system structure within the free finite element software CalculiX®. The coupling process and boundary condition transfer between the different disciplines is carried out automatically. The fully coupled process is used to analyse a complete low pressure turbine general arrangement. Results of the coupled investigation show relevant and interesting dependence between each discipline as well as good agreement when compared with the current method and with test data.