VIRTUAL GAS TURBINES PART Ⅱ: AN AUTOMATED WHOLE-ENGINE SECONDARY AIR SYSTEM MODEL GENERATION

摘要

The design and analysis of the secondary air system (SAS) of gas turbine engine is a complex and time-consuming process because of its complicated geometry topology. The conventional SAS design-analysis model generation process is quite tedious, time consuming. It is still heavily dependent on human expertise and thus incurs high time-cost. This paper presents an automated, whole-engine SAS flow network model generation methodology. During the SAS preprocessing step, the method accesses a pre-built whole-engine geometry model created using a novel, in-house, feature-based geometry modelling environment. It then transforms the engine geometry features into the features suitable for SAS flow network analysis. The proposed method not only extracts the geometric information from the computational geometry but also retrieves additional non-geometric attributes such as, rotational frames, boundary types, materials and boundary conditions etc. Apart from ensuring geometric consistency, this methodology also establishes a bi-directional information exchange protocol between engine geometry model and SAS flow network model, which enables making engine geometry modifications based on SAS analysis results. The application of this feature mapping methodology is demonstrated by generating the secondary air system (SAS) flow network model of a modern three-shaft gas turbine engine. This capability is particularly useful for the integration of geometry modeler with the simulation framework. The present SAS model is generated within a few minutes, without any human intervention, which significantly reduces the SAS design-analysis time-cost. The proposed method allows performing a large number of whole-engine SAS simulations, design optimisations and fast re-design activities.