A high-speed concentration probe for the study of gas turbine vane film cooling

Abstract

This paper describes the theory, design, development and usage of a high-speed, aspirated, choked-nozzle, hot-wire concentration probe. This probe, used in conjunction with a detectable foreign gas (FG) coolant, has been applied to the study of a gas turbine film-cooled nozzle guide vane (NGV) under simulated engine Mach numbers and Reynolds numbers.The FG mixture (30.2% sulfur hexafluoride and 69.8% argon by mass) is used in the tests to simulate the engine coolant to mainstream density ratio. This probe is designed to measure the FG concentration at a frequency of up to 200 Hz and with an uncertainty of ±2%. An example of coolant concentrations, downstream of the NGV row, extending across one and a half NGV passages, is presented in the paper to demonstrate the successful design of this high-speed concentration probe.

Experimental measurements of the flow field around a film-cooled blade leading edge using particle image velocimetry

“…[4][5][6][7] Several investigations have been carried out to study the flow field using intrusive techniques like hot wire probes. [8][9][10][11] However, due to the nature of this technique, it is complicated to obtain a spatial resolution of the flow field during the mixing of mainstream and cooling flow. Pietrzyk et al 12,13 performed a study using laser Doppler velocimetry (LDV), to know the effects of both the unit density ratio and the highdensity ratio on a flat plate.…”