Numerical Simulation and Experimental Study of the Effects of Disposal Space on the Flow Field Around the Combined Three-Tube Reefs

The artificial reefs placed on the seabed with different layouts and disposal spaces will produce variational flow field. The intensity and scale of the combined three-tube artificial reefs with different layouts at five Reynolds numbers（Re） are numerically investigated by use of the RNG k-ε turbulent model and SIMPLEC algorithm. A stationary no-slip boundary condition is used on the models and the bottoms, and the free surface is treated as a ＂moving wall＂ with zero shear force and the same velocity with inflow. In order to validate the simulation results, a particle image velocimetry（PIV） experiment is carried out to analyze the flow field. The numerical simulation results are consistent with the data obtained from experiment. The corresponding errors are all below 20%. Based on the validation, the effects of disposal space on flow field are simulated and analyzed. According to the simulation, in a parallel combination, a better artificial reef effect is obtained when the disposal space between two parallel reefs is 1.0L（L is the length of the combined three-tube reef model）. In a vertical combination, when the disposal space between two vertical reefs is 1.0L to 2.0L, the artificial reef effect is better.

Application Study of Trajectory Plume Model in Atmospheric Environmental Impact Assessment

[ Objective] The research aimed to study application of the trajectory plume model in atmospheric environmental impact assessment. [ Method] Trajectory plume model was used to retrospectively evaluate regional atmospheric improvement degree by fuel gas desulfurization project in Mawan Power Plant of Shenzhen. On this basis, we analyzed applicability of the model in atmospheric prediction of the construction project. [- Re- sult~ Under the situation of complex flow field and variable weather condition, the trajectory plume model displayed good prediction accuracy, to- gether with the use of flow field diagnosis model. Under complex weather condition, this model could be complementary to atmospheric environmen- tal quality prediction model recommended by new atmosphere guidelines, which had the value of popularization in future atmospheric environmental evaluation and planning. [ Conduslon~ Trajectory plume model had broad application potential in atmospheric environmental impact assessment.

NUMERICAL MODELLING OF FLOW FIELD IN A TIDAL RIVER AND THE NEAR FIELD OF INTAKE FOR A NUCLEAR POWER PLANT

This Paper concerns with the numerical modelling of flow field in a tidal river and in the vicinity of intake of a nuclear power plant. The hybrid method of fractional steps presented in [1] was adopted in this modelling. In order to simulate the local flow field nearby the water intake meticulously, the technique of the match of the coarse and fine grids was used. The numerical results are in good agreement with the in-situ measurements of the main current. The detailed data of local flow field nearby the intake provides the assessment of the sediment transport characteristics in the vicinity of intake of the nuclear power plant.

新一代运载火箭发射燃气动力学数值模拟

By using the mesh resolution control method based on the nozzle scale,a paralleled super numerical simulation and high-quality mesh model of the launch jet dynamics for new-generation launch vehicles was developed.Based upon this,a transient numerical simulation method,combining the pressure and velocity,tightly coupled algorithm and SST turbulence model,was used to complete the unsteady numerical simulation of the launch jet dynamics of the new-generation launch vehicles.The numerical simulation results of the launch jet dynamics,for the new-generation launch vehicles,demonstrated that despite the complex structure of the launch platform,the jet flows of the core stage and booster engines were generally smoothly channeled into the double deflecting trench through the launch platform’s diversion hole at the initial stage of ignition.After the lift off,the jet flows of the core stage and the booster engines began to affect and ablate the grillage-shaped beam and the adjoined surface of the launch platform adjacent to the booster engines.At a higher altitude after lift off,it could be seen for the new-generation launch vehicles the ablation range of high temperature and high-speed jet flows on the launch platform further expanded,which would have a severe ablation effect on the fuel filling tower near the booster engines and even all the support arms.The numerical simulation of launch jet dynamics also established that the jet flows embers at the bottom of the core stage rocket body continued to be affected for an extended period of time due to the large number of nozzles in the new-generation launch vehicles engine and the weak suction effect of the jet flows in the core-stage engines.