Near-wall transient heat transfer and flame–wall interaction (FWI) are topics of great importance in the development of downsized internal combustion (IC) engines and gas turbine technology. In this work we perform measurements using 1D hybrid fs/ps rotational CARS (HRCARS), thermographic phosphors (TGP) and CH* imaging in an optically-accessible chamber designed to study transient near-wall heat transfer processes relevant to IC engine operation. HRCARS provides single-shot gas-phase temperatures (40 µm spatial resolution and up to 3 mm wall-normal distances), while thermographic phosphors measures wall temperature and CH* measures the flame front position. These simultaneous measurements are used to resolve thermal boundary layer (TBL) development and associated gaseous heat loss for three important processes of gas–wall interactions: (1) an unburned-gas polytropic compression process, (2) FWI, and (3) post-flame and gas expansion processes. During a mild polytropic compression process, measurements emphasize that even a relatively small wall heat flux (≤5 kW/m²) yields an appreciable temperature stratification through a developing TBL. During FWI, thermal gradients induced by the flame are resolved within the TBL. Gases closest to the wall (y<0.2 mm) continue to experience thermal loading from polytropic compression until the flame is within ∼1.4 mm from the wall. Immediately afterwards, the wall first senses the flame as the wall temperature begins to increase. During FWI, gas temperatures up to 1150 K impinge on the wall, producing peak wall heat fluxes (620 kW/m²) and the wall temperature increases (ΔT_wall=14 K). Gaseous heat loss in the post-flame gas occurs rapidly at the wall, yielding a TBL of colder gases extending from the wall as wall heat flux slowly decreases. HRCARS further captures the rapid cooling of gases in the TBL and core-gas during the mild expansion and exhaust process.

近壁瞬态传热和火焰壁相互作用（FWI）是小型内燃机（IC）和燃气轮机技术发展的重要课题。在这项工作中，我们使用一维混合fs / ps旋转CAR（HRCARS），热成像磷光体（TGP）和CH *成像在光学可访问的腔室中进行测量，该腔室旨在研究与IC发动机运行相关的瞬态近壁传热过程。HRCARS提供单相气相温度（40 µm空间分辨率，壁正常距离最大3 mm），而热成像荧光粉测量壁温，而CH *测量火焰前沿位置。这些同时进行的测量用于解决气壁相互作用的三个重要过程的热边界层（TBL）形成和相关的气态热损失：（1）未燃烧气体多向压缩过程，（2）FWI，以及（3）火焰后和气体膨胀过程。在温和的多变压缩过程中，测量结果强调即使是相对较小的壁热通量（≤5kW / m²）通过显影的TBL产生明显的温度分层。在FWI期间，由火焰引起的热梯度在TBL内分解。最靠近壁的气体（y <0.2 mm）继续受到多方压缩的热负荷，直到火焰距离壁约1.4 mm以内。此后，随着墙体温度开始升高，墙体首先会感应到火焰。在FWI期间，高达1150 K的气体温度撞击壁，产生峰值壁热通量（620 kW / m ²），壁温升高（ΔT _wall= 14 K）。燃烧后气体中的气态热损失在壁处迅速发生，随着壁热通量的缓慢降低，产生从壁延伸出的较冷气体的TBL。HRCARS可在温和膨胀和排气过程中进一步捕获TBL中的气体和核心气体的快速冷却。