In this study, we generalize the classic thermal theory to account for both entrainment and detrainment effects occurring in the acceleration and deceleration phases of gravity current motion. Although the original thermal theory qualitatively captures the two phases of gravity current motion, the pure entrainment model appears to underpredict the gravity current velocity and the distance before the maximum velocity is reached. We theoretically show that detrainment increases the predicted maximum velocity of gravity current and extends the predicted distance before the maximum velocity is reached. Furthermore, based on the experimental data reported in the literature, the detrainment coefficient appears to increase as the bottom slope increases.
Journal of Hydraulic Engineering 136(10), pp.826-830