In this study, we apply particle image velocimetry (PIV), hot-wire anemometry (HWA), and large-eddy simulation (LES) to identify and characterize a key mechanism by which high-intensity turbulence measured in the “Hi-Pilot” burner is generated. Large-scale oscillation of the high-velocity jet core about its own mean axial centerline is identified as a dominant feature of the turbulent flow field produced by this piloted Bunsen burner. This oscillation is linked to unsteady flow separation along the expanding section of the reactant nozzle and appears stochastic in nature. It occurs over a range of frequencies (100–300 Hz) well below where the turbulent kinetic energy (TKE) spectrum begins to follow a – 5/3 power law and results in a flow with significant scale separation in the TKE spectrum. Although scale separation and intermittency are not unusual in turbulent flows, this insight should inform analysis and interpretation of previous, and future studies of this unique test case.

在这项研究中，我们应用粒子图像测速 (PIV)、热线风速测量 (HWA) 和大涡模拟 (LES) 来识别和表征在“ Hi-Pilot”中测量高强度湍流的关键机制燃烧器产生。高速射流核心围绕其自身的平均轴向中心线的大规模振荡被认为是这种带导向的本生灯产生的湍流场的主要特征。这种振荡与沿反应物喷嘴的扩展部分的不稳定流动分离有关，并且在本质上看起来是随机的。它发生在远低于湍动能 (TKE) 频谱开始遵循 – 5/3 幂律的频率范围 (100–300 Hz) 上，并导致在 TKE 频谱中具有显着尺度分离的流动。尽管尺度分离和间歇性在湍流中并不少见，但这种洞察力应该为对这一独特测试案例的先前和未来研究的分析和解释提供信息。