InterTurb: High-Pressure Turbine Rig for the Investigation of Combustor-Turbine Interaction

Abstract

This paper introduces a new 2-stage high-pressure turbine rig for aerodynamic investigations. It is operated by DLR Göttingen (Germany) and installed in DLR’s new testing facility NG-Turb. The rig’s geometrical size as well as the non-dimensional parameters are comparable to a modern engine in the small to medium thrust range. The turbine rig closely resembles engine hardware and features all relevant blade and vane cooling as well as secondary air-system flows. The effect of variations of each individual flow and different tip clearances on overall turbine efficiency will be studied. While the first part of the testing program will be based on uniform inlet conditions the second part will be run with a combustor simulator, which is based on electrical heaters and delivers a flow field similar to a rich-burn combustor. In order to find the optimum relative position for maximum turbine efficiency the combustor simulator can be rotated relative to the HPT inlet (clocking). For the same reasons the stators can also be clocked. The paper gives a brief overview of the testing facility and from there on focuses on the HPT rig features such as aerodynamic design, cooling and sealing flows. The aerodynamic optimisation of the stator vanes and shroudless rotor blades will be outlined. Further topics are the aerodynamic design of the combustor simulator, a comparison with engine combustors as well as the implementation in the rig. The paper also describes the rig instrumentation in the stationary and rotating system which most importantly focuses on measurements of efficiency and capturing of traverse data. The topic of blade and vane manufacturing via direct metal laser sintering will be briefly covered. The discussion of test results and comparison with numerical simulations will be the subject of a follow-up paper.

Ultra-Compact Traverse System for Transonic Annular Cascade

“…Facilities with longer run times generally use automated traverse systems, allowing finite areas to be surveyed with a single probe in a given run. Several systems have successfully deployed rotating stators paired with a radial traverse system (Dahlqvist et al, 2014;Wolf et al, 2011Wolf et al, , 2017. In the Test Turbine Rig at KTH Stockholm (Dahlqvist et al, 2014), stator rotation was achieved by attaching the stator disc to a hollow shaft, concentric with and opposite the rotor shaft.…”

Design, integration and operation of a rotating combustor-turbine-interaction test rig within the scope of EC FP7 project FACTOR

“…However, to realise inter-blading 2D area traverses, a circumferential traverse would be needed. The alternative solution of rotatable stator rings with a circumferentially fixed probe is elegant and advantageous concerning studying additional clocking effects, see (Wolf et al, 2017). For FACTOR that was excluded due to the extremely complex one-part main casing structure needed to provide optical access to all three blade rows.…”

“…The NG-Turb enables many hours of continuous testing in closed-loop for high resolution probe traverses and complex optical measurements. An example of another modern turbine test rig in this facility is given by (Wolf et al, 2017).…”