- Heat flux measurements of radiation emissions from turbulent premixed flames diluted with N 2 and CO 2 were taken to identify sensitivities of radiation heat loss to diluent fraction and species. This work is motivated by the desire to better characterise radiant heat transfer in the presence of combustion products, which can influence engine component lifetime and exhaust gas composition. A Medtherm radiometer (model 64-0.2-20) was used to measure radiation heat flux from undiluted, CO 2 diluted and N2 diluted jet-A/air flames at two concentrations of diluent. The equivalence ratio, turbulence intensity, and Reynolds number were held constant at 1, 10%, and 10000, respectively. Flames diluted with CO 2 were found to radiate more than their N 2 diluted counterparts, with total heat fluxes 50% higher at the extreme. Radiation intensity measurements were acquired using a FLIR SC6700 infrared camera to investigate fluctuations in flame emissions. To characterize the relative stability of each flame, standard deviations of each flame’s fluctuations in emissions were normalized by the average intensity. It was found that flame fluctuations increased rapidly with increasing diluent fraction, indicating changes in radiation emissions were caused by changes in both peak temperatures and combustion behavior.