Turbine Blade Internal Heat Transfer and Film Cooling Studies
Loading...
Date
2018-12-07
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Gas turbine engines are widely used in many industrial applications including aircraft propulsion, land-based power generation, and marine oil & gas industries. Currently, the highest turbine inlet temperature is around 1700°C. This turbine inlet temperature has already exceeded the yielding point of the blade material (1200°C). Therefore, advanced cooling techniques are employed to protect the hot-gas-path components from being heated and also ensure the long-lasting operation of gas turbines. In this study, experiments on the leading edge jet impingement cooling (first part), the flat plate film cooling (second part) and the endwall film cooling (third part) with more realistic features are proposed to improve the turbine airfoil cooling design.
The first part studies the impinging jet position effects (normal jet and tangential jet) and camera viewing angle effects. The impingement heat transfer distribution on the target wall is expected to obtain by using the transient liquid crystal (TLC) technique. Jet Reynolds numbers, 10,000, 20,000 and 30,000, based on the jet hole diameter, will be tested respectively. Numerical simulations using RANS will be carried out to explore the flow physics inside the impingement cavity.
The second part is focused on the film cooling effectiveness of two-row compound angled cylindrical holes by using the pressure sensitive paint (PSP) technique. The coolant-to-mainstream density ratio (DR) includes DR = 1.0 (low-temperature experiments), DR = 1.5 (intermediate DR) and DR = 2.0 (close to engine conditions) will be evaluated. Film cooling effectiveness distribution on the flat plate and the area-averaged film cooling effectiveness will be presented and compared for the optimization of the two-row compound cylindrical cooling hole design.
The third part investigates the endwall film cooling from two different cooling hole patterns: mid-chord row and downstream row. The isentropic exit Mach number will be at 0.5 corresponding to inlet Reynolds number of 380,000, based on the axial chord length of the vane. The free-stream turbulence intensity will be kept at 19%. This study will discuss the effects of the upstream injection flow to the endwall film cooling.
Description
Keywords
Turbine jet impingement cooling, Flat plate film cooling, Endwall film cooling