Experiments are performed for outwardly propagating spherical flames of R-32/air mixtures at constant pressure. A high-speed video camera captures shadowgraph images from which the flame radius as a function of time is extracted. Direct numerical simulations with an optically thin radiation model and detailed kinetics are performed to predict the flame radius and study the effects of stretch and radiation on the inferred laminar burning velocity. The simulations accurately predict the observed flame radius as a function of time. Analyses of the simulation results show that both stretch and radiation effects are important, occur concurrently, and make extraction of the unstretched adiabatic laminar burning velocity from the experimental data difficult.

进行了在恒定压力下向外传播R-32 /空气混合物的球形火焰的实验。高速摄像机捕获阴影图图像，从中提取出火焰半径随时间的变化。使用光学上薄的辐射模型和详细的动力学进行直接数值模拟，以预测火焰半径并研究拉伸和辐射对推断层流燃烧速度的影响。该模拟准确地预测了观察到的火焰半径随时间的变化。对模拟结果的分析表明，拉伸和辐射效应都很重要，同时发生，这使得从实验数据中提取未拉伸的绝热层流燃烧速度变得困难。