双组分层撞击流反应器浓度场混沌分析

采用平面激光诱导荧光技术测量双组分层式撞击流反应器撞击区浓度分布，利用混沌理论分析不同喷嘴间距、喷嘴直径和射流雷诺数下撞击流反应器浓度场混沌特征参数(关联维、Kolmogorov熵和最大Lyapunov指数)的变化规律。结果表明，撞击流反应器内浓度场混沌特征参数随喷嘴间距的增大呈上下波动的变化趋势，Kolmogorov熵在L=2d时达到最大。浓度场混沌特征参数随喷嘴直径增大呈上下波动的变化趋势，Kolmogorov熵在d=8 mm时整体上最大；射流雷诺数为Re=22 000时整体上混沌特征参数最佳。受二次撞击区的影响，撞击面上靠近二次撞击区各点的混沌特征参数有明显提高。

Chaos analysis of concentration field in two-component layered impinging stream reactor

Pressure signal, velocity signal and concentration signal of flow field in impinging stream reactor were characterized by nonlinearity and instability. Chaos theory is suitable for studying nonlinear dynamic problems. Secondary impingement occurs in the two-component stratified impingement reactor, and the flow field information in the impingement zone is more complex, which requires further analysis of its internal flow and mixing rules. In this work, the transient characteristics of fluid concentration signal in impinging stream reactor were studied by means of chaos analysis method, and the influencing factors and variation rules of non-linear characteristics of concentration field were analyzed. The concentration distribution in the impinging region of a two-component layered impinging reactor was measured by plane laser-induced fluorescence (PLIF) technique. The variation of the chaos characteristic parameters (correlation dimension, Kolmogorov entropy and maximum Lyapunov exponent) of the concentration field of the impinging reactor under different nozzle spacing, nozzle diameter and jet Reynolds number was analyzed by using the chaos theory. Based on chaos theory, the chaos characteristic parameters of concentration signal of impact surface were extracted, and the change rules of chaos characteristic parameters of concentration field of impact surface under different nozzle diameters, nozzle spacing and jet Reynolds number were analyzed, which provided theoretical basis for the research of flow field characteristics of multi-layer impingement reactor. The results showed that the chaotic characteristic parameters of concentration field in the impinging stream reactor fluctuated up and down with the increase of nozzle spacing. Kolmogorov entropy reached maximum at L=2d. The chaos characteristic parameters of concentration field fluctuated up and down with the increase of nozzle diameter. Kolmogorov entropy reached maximum at d=8 mm in the whole. The chaotic characteristic parameters at each point were optimal when the jet Reynolds number was 22 000 in th whole. Due to the secondary mixing in the secondary impact region, the chaotic characteristic parameters at points near the secondary impact region on the impact surface were significantly improved.