reportThis paper will explore the comparison of experimental (PFTIR) and simulation data obtained from assisted multipoint ground flares operating at high turndown. The flare assist is intended to encourage air entrainment for best combustion efficiency as well as reduce visible smoke. Operational envelopes of the assist to vent gas ratios are regulated on flare specific parameters. Experimental measurements have, however, measured low combustion efficiency even when operating within flare regulatory guidelines. This result is most likely due to the nonlinear nature of the flare combustion process and its response to regulatory constraints while being exposed to chaotic environmental conditions. Reliable and accurate methods for measuring, predicting and controlling flare performance across a wide range of conditions could offer significant environmental and economical advantages through better informed regulation, operation and ultimately high combustion efficiency. PFTIR measurements represent a promising technology for remote flare sensing, as they may be placed safely away from the combustion zone and report critical species concentrations along a line of sight from which a combustion efficiency may be computed. However, environmental conditions, experimental error and bias significantly affect the measured combustion efficiency. Advanced simulation techniques have also offered a promising avenue for evaluating flare performance. However, these simulation tools may require large computational resources or require high level expertise to run and evaluate. While both the experimental and simulation approach have their limitations, the combination of the two data sources can offer significant insight into the flare's performance and even offer realtime feedback for operation and control
