资源环境科技发展态势分析平台

The maximum solid phase concentration in geophysical turbulent gas-particle mixtures is essential for understanding the flow dynamics but is poorly known. We present laboratory experiments on turbulent mixtures of air and ceramic particles generated in a vertical pipe. The mixtures had maximum bulk concentrations C-max = 0.7-2.4 vol. % set by the onset of clustering and that increased with the degree of turbulence. Comparison with results of similar experiments with less dense (glass) particles reveals that C-max increases with the particle Reynolds number according to C-max = 0.78 x Re-p(0.17). Published results of experiments at specific Re-p in different configurations are consistent with our data, suggesting that the model for C-max may be generally applicable to turbulent mixtures. From our empirical laws we infer that natural turbulent gas-particle flows with Re-p similar to 10(2)-10(5) have maximum solid concentrations of similar to 2-5 vol. %.