Interaction between shock wave and solid particles: Establishing a model for the change of cloud's expansion rate.

This study seeks to discover the change of cloud's expansion rate with self-designed shock wave dispersion system. Transmission, diffraction and reflection could be observed intuitively when shock waves passed through solid particle layers. Results show that the longitudinal motion of particle group greatly influenced cloud's volume growth, thus, the maximum rate of longitudinal expansion of clouds was almost twice that of lateral expansion. The cloud growth rate and volume acceleration increased with smaller particle size, thicker particle layer and stronger shock wave intensity. Also, the expansion rate initially had a drastic decrease, small particles made clouds volume acceleration unstable and experienced a subsequent swift rise. Shock wave intensity influenced diffraction and reflection formation waves as well as the cloud's shape and expansion rate. This study therefore proposed a controlling model for cloud's expansion rate, which could illustrate differences between acceleration stage of dynamic action and deceleration stage of resistance action. Unlabelled Image • The leading factor of cloud volume growth is longitudinal motion of particle group. • The maximum vertical expansion rate of cloud is almost twice that of the lateral. • Small particles make clouds growth acceleration unstable and rise suddenly. • Shock wave strength affects diffracted and back wave formation, then clouds shape. • A controlling mechanism for cloud cluster expansion rate is proposed. [ABSTRACT FROM AUTHOR]