In this work, we report on the direct measurement of heat release rates via simultaneous laser-induced fluorescence of OH and CH2O radicals using planar laserinduced fluorescence (PLIF). The product of the two images is shown to correlate with the forward production rate of the HCO radical, which in turn has been found to correlate well with heat release rates in premixed hydrocarbon flames. Heat release rate measurements were also taken with OH* for comparisons with the results from the laser-based technique. The measurements were made in a lean turbulent premixed flame subject to acoustic forcing; this flame mimics the instabilities encountered in lean premixed pre-vaporized combustors (LPP). As the scheme is based on probing radical species that participate in the major heat release reactions, it is the closest nonintrusive measure of heat release rate currently available and thus presents a very useful diagnostic tool in combustion research. PLIF平面激光誘導(dǎo)熒光火焰燃燒檢測(cè)系統(tǒng)