Abstract:

The particle dispersion characteristics of the dense gas-solids two-phase coaxial jets were investigated with high-speed camera.The results showed that with increasing gas velocity，three particle dispersion modes were observed：shear dispersion，wave dispersion and oscillating dispersion，after the particle flow passed through the intact length.The normalized intact length decreased with increasing gas velocity.For the wave dispersion，the unstable wavelength increased linearly with axial distance at different gas velocities.For the oscillating dispersion，oscillating frequency decreased at first and then increased with increasing gas velocity，so the oscillating frequency had a minimum when the gas velocity was about 65 m·s^-1.

Key words:

稠密气固两相流, 未弥散长度, 颗粒弥散, 同轴射流

摘要：

采用高速摄像仪对稠密气固两相同轴射流中颗粒的弥散特性进行了实验研究。实验结果表明，颗粒流离开未弥散长度后，随气体射流速度增加，存在三种弥散模式，分别为剪切弥散，波状弥散和振荡弥散。未弥散长度随气体射流速度（雷诺数）的关系为 。波状弥散模式下颗粒流波动波长沿射流轴线的发展规律为 。在振荡弥散过程中，随着气体射流速度的增大，颗粒流振荡的频率先减小后增大，在气体速度约65 m·s^-1时振荡频率最小。

关键词:

稠密气固两相流, 未弥散长度, 颗粒弥散, 同轴射流