Session: 35-04 Hot Streaks and Sealing Flows

Paper Number: 81623

81623 - Approximating Gas Turbine Combustor Exit Temperature Distribution Factors Using Spatially Under-Sampled Measurements 

The temperature field at the combustor exit plane in gas turbine engines is highly unsteady and complex, with large radial and circumferential variations. The discrete arrangement of fuel and dilution air jets yield significant circumferential variations, while the lining coolant flow results in strong radial temperature gradients. Two widely adopted parameters include the radial temperature distribution factor (RTDF) and the overall temperature distribution factor (OTDF) to quantify combustor exit temperature nonuniformity. The state-of-the-art approach of characterizing the combustor exit temperature nonuniformity is to carry out an extensive traverse along the circumferential direction at a spatial resolution of two to three degrees. With hundreds of measurements in place, the combustor OTDF and RTDF can be obtained. Though the approach is in practice, this involves the design of complex traverse mechanisms and can be costly. To address this challenge, this paper presents a novel method for predicting combustor exit TDFs using much sparse measurements.  The effectiveness of the approach was examined using three engine representative combustor temperature measurements covering a single-burner, double-burner, and entire annulus. In all cases, the multi-wavelet approximation method yields almost identical RTDF to experiment with most variations less than 1.0% using much sparse measurements. In addition, a sensitivity analysis of the method is conducted to investigate the influence of the data size, probe locations, and the number of wavelets. Finally, guidelines for the selection of those parameters were presented.

Presenting Author: Fangyuan Lou Tsinghua University

Presenting Author Biography: Fangyuan Lou obtained his PhD from Purdue University and is currently an assistant professor in Tsinghua University. His research focuses on turbomachinery aerodynamics and measurement techniques.

Authors:

Fangyuan Lou Tsinghua University