The core technique of flood forecast and pre-warning of a river basin is the numerical simulation of flood process in a complicated flood control system. According to the structural features, flood features, and flood process mechanism of a large and complicated flood control system, a 1D and 2D coupled numerical simulation model was established. The 1D model was used for the trunk river and main branches, and the 2D model was used for flood districts. The coupled 1D and 2D was used to simulate the flood regulation and process in rivers, lakes, flood districts, and floodways. A case study was conducted in the section from the Wangjiaba to Bengbu floodgates in the middle reach of the Huaihe River. The coupled model was employed to synchronously simulate the branch rivers and trunk flood of the river basin and to improve the accuracy of flood simulation, flood forecast, and regulation of the river basin. The parameters of the model for simulating the flood process of the Huaihe River Basin in 2003 were calculated and verified, and the flood process in 2007 was demonstrated. The simulated results show that the flood regulation and process can be accurately simulated by the proposed numerical model, and the accuracy requirements can be satisfied. Finally, the model was applied to the effect analysis of a four-grade emergency flood control plan in the Huaihe River Basin.

A mathematical model considering the transmission of a partially coherent Gaussian Schell-model (GSM) beam in slant turbulence atmosphere of heterodyne detection was established. A closed-form expression of the weighting factor for the partially GSM beam at the receiving end was derived. The effect of the beam mode on the performance of the proposed detection system was theoretically investigated. The results show that the proportion of the fundamental mode and heterodyne efficiency can be optimized by controlling the waist radius of the signal and local oscillator beams. The inner scale of turbulence significantly affects the heterodyne efficiency and normalized M 2 . With a larger mode order, the proportion of the fundamental mode and heterodyne efficiency are lowered.

The characteristics of the fluctuating pressure in the boundary layer of an axisymmetric body have been investigated experimentally using dynamic pressure measurements and Schlieren photograghs. Data were acquired at subsonic and super-sonic Mach numbers. The angles of attack ranged from 0° to 5°. Pressure signals were measured simultaneously in several positions along the model and were analyzed both in the time and frequency domains. The Mach number shows the relevant influence on . Furthermore, the pressure fluctuations’ level decreases with the increasing of Mach number except M=1.15. And it is shown that, the location along the axis of the model and the angles of attack have small effect on pressure fluctuations.

The characteristics of the fluctuating pressure for the 15° expansion corner of an axisymmetric body have been investigated experimentally using dynamic pressure measurements and Schlieren photograghs. Data were acquired over a Mach number ranging from 0.8 to 0.92. The angles of attack ranged from 0° to 5°. Pressure signals were measured simultaneously in several positions along the axis of model and were analyzed both in the time and frequency domains. The results indicate that large fluctuating pressure loads, resulting from the shock/boundary layer interaction exist at the transonic flow condition, because of the shock/boundary layer interaction. The maximal pressure fluctuation occurs after the expansion corner at Mach number 0.86. With the Mach number increasing, the position of the normal shock moves downstream. In the shock/boundary layer interaction region, the fluctuating pressure changes significantly with different angles of attack. Moreover, this interaction has a main effect of enhancing the power spectral density in low-frequency range (f≤5KHz).