Abstract
This paper demonstrates the application of a thermometry method in turbulent sooting non-premixed flames using filtered Rayleigh scattering (FRS). Fuel tailoring is used to establish a specific ${{\rm{C}}_2}{{\rm{H}}_2}$-based fuel mixture such that temperature can be determined accurately by a single FRS measurement over the entirety of mixture fraction space, or equivalently, for all relevant thermo-chemical states. Evaluation is performed in a hierarchy of flows to establish measurement precision and accuracy. Initial assessments in a series of heated fuel mixtures; non-sooting, near-adiabatic flat flames; and laminar non-premixed sooting flames show accuracy of the approach over a full range of expected temperatures and high single-shot measurement precision (e.g., ${{65}} \lt {\rm{SNR}} \lt {{80}}$) for temperatures between 1900 and 2200 K. Subsequently, 2D temperature measurements are evaluated in a turbulent non-premixed sooting flame. For the current fuel mixture, the local mixture-averaged Rayleigh scattering cross section is nearly constant over all composition space, and thus traditional laser Rayleigh scattering (LRS) is used as a measurement standard in the absence of soot. The results show excellent agreement between the proposed FRS thermometry approach and LRS in non-sooting regions. In the presence of soot, the proposed FRS-based approach shows no signs of interference. In addition, 2D temperature imaging shows high SNR (60–74) over all temperature conditions. Thus, we believe the proposed methodology successfully provides a high-resolution 2D temperature method under turbulent sooting flame conditions.
© 2021 Optical Society of America
Full Article | PDF ArticleMore Like This
Thomas A. McManus and Jeffrey A. Sutton
Appl. Opt. 58(11) 2936-2947 (2019)
Abinash Sahoo, Aravind Ramachandran, Venkateswaran Narayanaswamy, and Kevin M. Lyons
Appl. Opt. 61(9) 2338-2351 (2022)
Sean P. Kearney, Robert W. Schefer, Steven J. Beresh, and Thomas W. Grasser
Appl. Opt. 44(9) 1548-1558 (2005)