High-Speed IR Imaging for Measurement of Wall and Gas Temperatures in Combustors

The purpose of this action is to add FY22 UFR funds in the amount of $204,578.00. GRANT#13604076.-Submitted to: Sea-Based Aviation Propulsion Division (Code 351), Steven Martens. PI: Jacqueline O#Connor, Mechanical Engineering, Pennsylvania State University. For public release. Increasing engine performance and thermal efficiency, a goal of the Office of Naval Research (ONR), can be achieved through increasing combustor firing temperature. Increasing temperature can also result in durability issues for the combustor hardware, including surface burning, thermal stresses, and accelerated component degradation. Prediction of these durability issues is difficult, however, as combustor flow fields are complex and computational fluid dynamics (CFD) predictions often do not properly capture the multi-physics nature of combustion. As a result, predictions of combustor wall temperatures are often inaccurate. In particular, typical combustion simulation does not account for thermal radiation with sufficient fidelity; the distinctively different radiative characteristics of the condensed phase (soot) and the gas phase at elevated pressures is challenging for models to capture, which can easily lead to prediction with more than a 50% error in radiative heat flux. Additionally, the transient behavior of combustion systems has been given very little treatment in the literature, but could be a significant driver of thermal stress on combustor liner components. In this situation, it#s not just liner temperature, but the heat flux variation rate that drives material degradation. Experimental diagnostics of the radiative and convective heat flux under the above-mentioned conditions is also very limited, hence there lacks a fundamental understanding of the near-wall heat transfer within a modern combustor. This DURIP proposal aims to acquire a high-speed mid-wave infrared (HS-MWIR) camera system from Telops in order to measure both wall and gas temperatures in high-temperature, reacting conditions. This camera, with a maximum frame rate of 3100 Hz and eight spectral filters for measuring a range of species and blackbody surfaces, will provide significant flexibility in measuring both combustion and heat transfer phenomena in a range of different experiments. The high-speed capability will also allow for capturing both stationary and transient processes, a unique and critical capability for the study of combustor liner heat transfer. This camera will be used for the PI#s current ONR program, #Relative Impact of Convective vs. Radiative Heat Loading in Gas Turbine Combustors,# (Grant #N00014-20-1-2278, program monitor Steven Martens) and provide unique and detailed measurements of both gas and wall temperatures inthe combustor at steady-state and transient conditions. These measurements will be critical for comparison to the simulations provided by the project#s co-PI, Dr. Xinyu Zhao at UCONN. It will also be useful in a number of other applications in the PI#s lab, including work in combustion instability, durability of ceramic materials for engine hot section applications, soot formation from alternative jet fuels, and hydrochar combustion. Finally, it will support education of both graduate and undergraduate students in the laboratory and in a variety of courses that the PI teaches, including introductory courses like thermodynamics and advanced graduate courses in combustion.