Ni's project

We should engage in the basic theory of two-phase flow and its application research in dynamic geomorphology and environmental science and engineering. In this paper, the mechanism of solid-liquid two-phase flow and sediment movement with high sediment concentration is studied emphatically. In the aspect of solid-liquid two-phase flow, starting with the micro-motion analysis of particles in kinetic theory, a description method of high-concentration solid-liquid two-phase flow motion is proposed, and the relationship between particle velocity distribution functions under high concentration and low concentration is found. The theoretical model can describe the movement of low concentration and high concentration solid-liquid two-phase flow at the same time, which overcomes the defects of traditional methods. In the aspect of wind-sand two-phase flow, a set of most systematic and comprehensive wind tunnel measured data at home and abroad is obtained. A method to determine the wind speed profile that can reflect the velocity characteristics of sand-laden airflow inside and outside the thermocline is put forward, and the formulas of wind speed distribution and sand transport rate that can fully reflect the influence of particle size are obtained, revealing the influence of wind tunnel scale change and side wall on sand-blown movement. The rapid assessment method of water and soil loss in river basin, the health assessment method of river system and the comprehensive optimization method of reclamation project based on multi-objective and multi-constraint conditions such as ecological environment protection are put forward and applied in practice. He has presided over more than 20 major projects of the National Natural Science Foundation, scientific and technological cooperation projects of the European Union (INCO-DC) and Sino-Canadian cooperation projects (CIDA). Won the second prize of ministerial scientific and technological progress and many other scientific and technological awards. More than 20 published papers were included in SCI, 40 were included in EI, and 2 monographs were published. He was awarded the China Youth Science and Technology Award and one of the top ten postdoctoral fellows in China.