Experimental and computational investigation of inlet temperature profile and cooling effects on a one and one-half stage high-pressure turbine operating at design-corrected conditions.

摘要

This dissertation presents for the first time measurements and analysis of the flow features of a high-pressure one and one-half stage turbine operating at design corrected conditions with vane and purge cooling as well as vane inlet temperature profile variation. A concurrent experiment at the Gas Turbine Laboratory provided the first set of pressure and heat-flux measurements for a fully-cooled turbine (vane row cooled and blade row cooled) operating at design corrected conditions [4, 5], but the more detailed data investigating the influence of different cooling flows and vane inlet temperature profiles are still being analyzed. The experimental program presented in this dissertation contains data to determine the influence of each cooling region and temperature profile on the flow over the uncooled blade by adjusting the cooling flow rates from the vane and from the purge cavity (between the vane and the rotor disk) for experiments with a uniform, radial, or hot streak inlet temperature profile.;The data set presented here represents the first set of its kind to utilize variation of cooling flow rates through the same geometry to identify the regions of cooling influence on the downstream blade row. The influence of cooling on the pressure surface of the uncooled blade is much smaller than on the suction surface, but a local area of influence can be observed near the platform.;This is also the first experimental program to investigate the influence of vane inlet temperature profile on a cooled turbine operating at design corrected conditions. The vane inlet temperature profile has a substantial effect on the temperature measured at the blade leading edge and the Stanton Numbers deduced for the uncooled blade airfoil. While the temperature profile is slightly reshaped passing through the vane, a radial profile introduced at the vane inlet can still be clearly measured at the blade.;A concurrent effort to predict the blade leading edge and platform temperatures for the uncooled portions of this experiment using the commercial code FINE/Turbo is also presented. This investigation is not intended as a detailed computational study but as a check of current code implementation practices and a sanity check on the data. It is found that while reasonable agreement can be achieved in many regions, current practices used for generating accurate surface-pressure predictions are not sufficient to create accurate temperature predictions for all locations. The best predictions are generated using isothermal wall boundary conditions with the nonlinear harmonic method. This is a novel prediction type that could only be performed using a development version of FINE/Turbo. Improvements in prediction accuracy will require a more dense computational mesh as well as better definition of the wall temperature distribution and inlet temperature profile. (Abstract shortened by UMI.)