Design and operation of a two spool high pressure test turbine facility

Abstract

In order to reduce the specific fuel consumption and consequently to minimise the CO2 emission of aircraft turbine engines, development and integration of a contra-rotating open rotor architecture is a promising alternative to the classical turbofan engines. The large dimensions of future contra-rotating fans lead to lower rotational speed and furthermore a bigger size of the powering low pressure stages. In such engines the flow leaving the high pressure turbine (HPT) has to be guided to the low pressure turbine (LPT) inlet at larger diameter, if possible without interference or separation. To minimise weight and costs of the aircraft engine the flow diverting mid turbine frame (MTF) has to be designed preferably short. One goal of the EU project DREAM is to analyse the flow through such a MTF with turning struts and a downstream arranged counter rotating LPT. The investigation of these complex interrelationships needs a test facility with engine representative conditions. To perform these investigations the continuously operating transonic test turbine facility (TTTF) at Graz University of Technology has been adapted. This test setup consists of a redesigned HPT, a newly developed LPT and a turning mid turbine frame (TMTF). The shafts of both turbines are mechanically independent, so the test rig allows a realistic two shaft turbine operation. To investigate the capabilities of the test rig in terms of operating point and off design position the rig has been equipped with total pressure and total temperature rakes in several planes. The rig is designed to be completely traversed in circumferential position. This paper presents the design and summarise the first operation experiences of the two spool rig.