论文标题
一种用于预混合燃烧的新型紧凑型主动湍流发生器：无反应流动特性
A new compact active turbulence generator for premixed combustion: Non-reacting flow characteristics
论文作者
论文摘要
开发，测试和表征了一种新的紧凑型主动湍流发生器，该发生器扩展了在湍流预燃烧研究中使用的此类发电机的功能。发电机由两个类似于两个弓形的叶片组成。进行热线诊所和高速成像，以表征发电机和叶片动力学产生的非反应流动。检查了两个平均体积流量为5.0和7.0 m/s。为了进行比较，除了开发的发电机外，还针对自由喷气机以及一个和两个穿孔的板进行了测试。结果表明，中心线根均方根速度波动可能变为1.8 〜m/s，这比文献中的几倍大于活性网格产生的反应流量的几倍。对于新开发的设备，一维动能的幂律衰减分别为5.0和7.0 m/s的平均体积流速分别为-1.0和-1.3。对于新开发的设备，归一化的耗散速率最小，而能量耗散速率最大。速度数据的光谱分析并未显示出与叶片旋转频率相等的主要频率。并且，一个维动能和耗散光谱遵循-5/3和1/3幂律关系。结果表明，与对应于其他测试的湍流发生器相比，新开发的设备产生的小涡流会更快地消散湍流动能。
A new compact active turbulence generator is developed, tested, and characterized, which extends the capabilities of such generators used in turbulent premixed combustion research. The generator is composed of two blades that resemble the shape of two bow-ties. Hot-wire anemometry and high-speed imaging are performed to characterize the non-reacting flow produced by the generator and the blades dynamics, respectively. Two mean bulk flow velocities of 5.0 and 7.0 m/s are examined. For comparison purposes, in addition to the developed generator, tests are also performed for a free jet as well as one and two perforated plates. The results show that the centerline root mean square velocity fluctuations can become about 1.8~m/s, which is several folds larger than that in the literature for reacting flows generated by active grids. For the newly developed device, the power-law decay of the one-dimensional kinetic energy is -1.0 and -1.3 for the mean bulk flow velocities of 5.0 and 7.0 m/s, respectively. The normalized energy dissipation rate is smallest for the newly developed device, while the energy dissipation rate is the largest. The spectral analysis of the velocity data does not show dominant frequencies equal to the blades rotation frequencies; and, the one dimensional kinetic energy and dissipation spectra follow -5/3 and 1/3 power-law relations. It is shown that, the small eddies produced by the newly developed device dissipate the turbulent kinetic energy faster than those corresponding to the rest of the tested turbulence generators.
