Lake current is the cause for the transport of many matters such as suspended sediment, algae, contaminant, therefore, it must be estimated fairly accurately. Generally speaking, the flow in many lakes is weak and the flow direction is follows dominated mainly by the wind direction on lake surface. Correct simulation of the wind-driven current in a lake requires using a three-dimensional hydrodynamic numerical model. The main factor affecting the lake hydrodynamic processes is wind. Because wind-driven current have important influence for the matter exchange and energy transform in a lake, and field observations are comparatively difficult, numerical modeling is the main method to estimate the wind-driven current nowadays. The numerical modeling of 3D tidal flow and mass transportation in this study was performed using the Princeton Ocean Model (POM). The model is validated by calculating wind-driven current in a rectangular flume [1][2]. The contaminant transport modeling in the Yangchenghu Lake is performed with POM using an orthogonal curvilinear grid in horizontal direction and sigma coordinate variation in vertical direction. An analysis of model results is presented.

Being required to have the functions of both pumping and drainage, some pumping stations are suggested to adopt two-way standard tube tubular pump unit, which also meets the needs of low heads and large discharge condition. In the paper, the velocity field of flow passage among the passage of tubular pump unit is measured by micro 5-hole probes system, in order to provide experimental evidences for improving the pump unit performance further. Experimental results show that axial velocity become larger from the wall to the center of inlet passage; however, axial velocity in the outlet passage center is less than that near the wall. At the same time, the uniformity of axial velocity in the outlet passage also turns badly. It is also found that transverse velocity of inlet passage is small and it becomes larger in the outlet passage because of the outlet circulation. The axial velocity of curved pipe becomes less from the inside to the outside, which is caused by centrifugal effort. The above data can make for both reference to design perfect tubular pump unit and comparison with CFD results.

In order to improve the drainage system of buildings in China, the drainage system based on pressure pipeline is studied. Firstly, the development background of building drainage in China is described, and the flow algorithm of pressure pipeline is introduced. On this basis, the drainage test of single riser and double riser system is designed. Through comparative analysis of the test, the drainage characteristics of the pipeline drainage system are obtained, and the relevant design methods of the drainage system in buildings are obtained based on the pressure pipeline. The drainage performance of double risers is better than that of single risers. Double risers should be used as much as possible in construction, especially in high-rise buildings. Drainage of high-rise buildings is complex, and large changes in water pressure are easily formed in pipeline, which may damage indoor water-using equipment, make odorous gases in pipelines enter indoors, and destroy living environment. The research results can provide data reference for building drainage design, provide parameter basis for testing standards of drainage capacity of residential drainage system, and improve building drainage system in China.