Experimental Methods to Improve Multi-Parameter Estimation of filtered Rayleigh scattering for High Temperature Flows
K.J.B. Hanley(1), K.T. Lowe(1), J. Meadows(2)
1: Kevin T. Crofton Department of Aerospace and Ocean Engineering, Virginia Polytechnic Institute and State University, United States
2: Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, United States
DOI:
This work experimentally evaluates two strategies for improving the estimation uncertainty in multi-parameter FRS measurements in high temperature, Doppler broadened flows: frequency scanning over multiple Iodine absorption features and joint estimation using multiple camera perspectives. These strategies were tested on a Honeywell TFE-731 turbofan exhaust, where the measurement spans both low and high Doppler broadening conditions. It is found that the use of multiple Iodine absorption features reduced the median absolute errors in total temperature and total pressure by a factor of up to 4.2. Furthermore, multi-camera joint estimation, relative to single-camera estimation, reduced the median absolute errors by a factor of up to 17.4. The reduction in uncertainty using these strategies also follow similar trends. These results demonstrate that the addition of highly informative observations can significantly reduce measurement uncertainty and error.
