The application of laser diagnostics to high pressure combustion phenomena is particularly challenging, especially in practical combustors such as rocket motors. In this study, temperature measurements using Laser Induced Thermal Grating Spectroscopy (LITGS) are demonstrated in oxygen enriched CH₄/O₂/N₂ premixed laminar flames at pressures up to 1.0 MPa. We use a previously developed OH absorption LITGS technique to determine product gas temperatures from 0.3 to 1.0 MPa, for both high temperature oxygen-enriched and pure-oxygen flames, for measurements up to 3000 K. Further, we demonstrate how it is necessary to correct the measurements for the local absorption of laser light to obtain accurate temperatures, and offer a technique for producing the correction by using different laser energies. Once the correction is applied, we demonstrate that the measurements at 0.5 MPa are within 1.6% of the adiabatic non-strained flame temperatures, with a standard deviation of about 160 K, thus offering a competitive method for the challenging conditions at high pressures and temperatures. The values obtained at derived temperatures at 1.0 MPa were lower than the adiabatic unstrained flame temperatures, which could possibly be attributed to loss mechanisms.

将激光诊断应用于高压燃烧现象特别具有挑战性，尤其是在诸如火箭发动机的实际燃烧器中。在这项研究中，在富氧的CH ₄ / O ₂ / N ₂中证明了使用激光诱导热光栅光谱法（LITGS）进行温度测量。预混合的层流火焰，压力高达1.0 MPa。我们使用先前开发的OH吸收LITGS技术确定高温富氧火焰和纯氧气火焰的产品气体温度从0.3到1.0 MPa，测量范围高达3000K。此外，我们演示了如何校正测量激光的局部吸收以获得准确的温度，并提供一种通过使用不同的激光能量进行校正的技术。一旦进行了校正，我们证明了在0.5 MPa下的测量值在绝热非应变火焰温度的1.6％范围内，标准偏差约为160 K，从而为在高温高压下具有挑战性的条件提供了一种有竞争力的方法。在导出温度为1时获得的值。