明渠水流自由面失稳与滚波发育研究

滚波(roll wores)是明渠均匀水流自由面失稳后发育的一系列波动现象.它的发生会带来诸多不利后果,如溢流、掺气、对河(渠)道水工建筑物的超负荷压力或应力等.滚波具有浅水长波的特征,因而利用一维浅水方程开展滚波问题的研究,取得了丰富的成果:如判定自由面稳定性的临界弗劳德数、演化方程的理论解及试验、数值研究等.构建能够更好地刻画滚波波动特征的理论模型,研究浑水、动床(包括床面变形)条件下滚波的形成及其演化规律,是今后滚波研究的一个重要方向.

Instabilities of free surface in open-channel flows and development of roll waves

Roll wave often develops as the free surface loses its stability in an open-channel steady,uniform flow.They can bring about a series of unfavorable affects,such as the spilling,the mixing gas,the excessive pressure or the stress on hydraulic engineering projects,etc.Roll waves have the characteristics of shallow long waves.Considerable progresses are made in terms of theoretical,experimental and numerical studies by using the shallow-water equations.To build better mathematical model needs to takes into account viscosity,the vertical velocity acceleration,the shock profile,etc.and study the occurrence and evolution of the roll waves in sediment-laden flow over the movable bed(including bed deformation).It is of great importance in engineering practice and theoretical research.