中文摘要：

应用基于颗粒动力学理论的欧拉-欧拉模型，模拟了不同表观气速下的气固密相流化床，测定了冷模流化床中压力脉动沿床高的变化，将CFD模拟与实验得到的床层压力分布及压力脉动频谱图相对照，验证了数值模拟方法的正确性。采用统计分析的手段对模拟得到的颗粒温度时间序列进行研究，结果表明，随着表观气速的增加，颗粒温度增大，颗粒温度时间序列的标准偏差增大，平坦度基本不变。将声能量理论与颗粒温度相结合并比照声能量沿床高的变化趋势，发现颗粒温度、颗粒温度时间序列的标准偏差及平坦度可用于确定颗粒运动“滞留区”的位置。引入颗粒温度谱，并根据脉动能的级串理论将颗粒温度谱划分为含能尺度、惯性尺度和耗散尺度，发现颗粒温度谱在惯性尺度内普遍偏离Kolmogorov-5／3定律而趋向符合Levy—Kolmogorov定律。在Levy-Kolmogorov定律的适用范围内，“滞留区”的颗粒温度谱衰减指数达到最大值，据此提出颗粒温度谱的衰减指数具有表征“滞留区”位置的潜力。

英文摘要：

The Euler-Euler two-fluid model combined with kinetic theory of granular flow was used to simulate the gas-solids dense phase fluidized bed at different superficial velocities. The experiments were carried out to compare the profile of pressure and pressure fluctuation power spectrum with the CFD simulated results, and the simulation method was validated. Statistical analysis and spectral analysis were used to investigate the granular temperature time series. It was shown that as superficial velocity increased, average and standard deviation of granular temperature time series increased, while flatness factor almost remained constant. By integrating acoustic energy theory into granular temperature and referring to acoustic energy profile with bed height, the average, standard deviation and flatness factor of granular temperature time series were used to determine the stagnant zone of particle motion. Furthermore, granular temperature spectrum was introduced and divided into energy-containing scale, inertial scale and dissipation scale based on the cascade theory of fluctuation energy. In the inertial scale, granular temperature spectrum deviated from Kolmogorov -5/3 law and tended to obey Levy-Kolmogorov law. In the application scope of Levy-Kolmogorov law, the decay index of inertial scale in the stagnant zone achieved a maximum, according to which the identification of stagnant zone by the decay index of granular temperature spectrum was proposed.