Interaction of solid particles of two-phase flow with a surface of complicated profile
The article is devoted to investigation of coefficients of velocity restitution of solid particles of two-phase flow at their interaction with a surface of a body. Experimental and theoretical study shows that the roughness of a surface essentially influences rebound parameters of particles. Thus the drag of a body from solid particles depends on peculiarities of the form and roughness of a surface. The experimental investigation of integrated (average on a surface) coefficients of velocity restitution of particles is carried out. In experiments there were used models, the surface of which had the given features. The experiments have shown that the features of a profile of a surface considerably influence the value of coefficient of velocity restitution. The calculation of coefficients of velocity restitution for such surfaces is executed with using the coefficients of velocity restitution measured for a smooth surface. It is shown that the determination of integrated coefficients of velocity restitution of particles for such surface requires to take into account multiply interactions of a particle with the surface. The influence of a ratio of the specific sizes of a particle to magnitudes of surface peculiarities on the behaviour of impulse transfer is considered. It is shown that at small angles of a surface inclination the coefficient of restitution of normal velocity can be more than unit, and the coefficient of restoration of tangential velocity can decrease down to zero. In defining the coefficient of velocity restitution of particles it is necessary to consider a level of roughness and the surface profile peculiarities