Real-Time Multi-Color Techniques for Identification and Filtering of Burst Signals in Jet Engine Pyrometers

Abstract

A Multi-color Pyrometry (MCP) experiment was carried out on a aircraft engine to study the nature of hot particulate bursts generated from the combustor at certain engine conditions. These bursts of hot particulates lead to intermittent high-voltage signal output from the line-of-sight (LOS) pyrometer which is ultimately detected and used by the onboard Digital Engine Controller (DEC). The investigation used a high-speed MCP system designed to detect bursts and identify their properties. Results of the radiant temperature, multi-color temperature and apparent emissivity are presented. The results indicated that the apparent emissivity calculated during the signal burst was lower than that of the blade. The root cause for the signal burst was identified as soot particles generated as by-product of combustion under certain conditions. A digital filter technique is developed to send reliable temperature signal to DEC for robust engine control even under the engine bursting conditions. Simulink model is used to simulate the performances of the design and showed great promise for engine control.