QUASI-THREE DIMENSIONAL VERIFICATION OF THE MODULAR AXIAL COMPRESSOR DESIGN APPROACH

摘要

In an article published some time ago, the authors investigated the idea of breaking down the [multi-stage] compressor component of the typical turbofan engine into modules. The motivation for this work stems from a "Lean Engineering" approach to gas turbine engine design. Five (5) modules were created; they are the inlet, front, core, rear, and exit modules. The intent is to maximize the size of the core module, as represented by the number of stages. Thus, many different compressors can share the core module, which will greatly reduce the Lifecycle costs for the fleet. The next stage of this work focuses on the Meanline and Throughflow design and analysis of two different compressors that share an 8-stage core. The first compressor, HPC-1, is a 10-stage compressor operating at 9,000 rpm, having 100 Kg/sec inlet mass flow rate, and a 13.5:1 overall pressure ratio. HPC-2 is a 13-stage modular upgrade of HPC-1, operating at 9,700 rpm, having an inlet mass flow rate of 140 Kg/sec, and a 27:1 overall pressure ratio. Applying the modular concept, the first and last stages (of HPC-1) have been removed and replaced by 2 and 3 stages, respectively. Additionally the inlet and exit modules have been redesigned as well. Preliminary Meanline analysis showed that this concept could present challenging boundary conditions for the design of the interface stage; the name assigned to the first stage of the core module. The conditions entering that stage represent a critical hurdle to the viability of this method. Slight variations in corrected speed and pressure ratios for stages 1 and 2 of the modular upgrade, HPC-2, provided the necessary realignment of the core module. The pressure ratio of the core module differs by less than 1% for both compressors. And in both instances, the corrected speed is virtually identical. Throughflow analysis, conducted using T-AXI, confirms the redesign and the viability of the method.