Papers by Keyword: Jet Velocity

Abstract: There are often people and goods in and out of the dinning room door, so the door is often open. Heating and air conditioning construction to save energy and to prevent the outdoor air form influencing on indoor environment, set up the air curtain at the entrance of the dinning room to stop outdoor air, the frequently-used air curtain is beam type of air curtain.The project in view of the dinning room of the new campus of hebei university of science and technology, sets up air curtain physical model of the ground floor dining room door at the first area, and carry on reasonable simplification, make sure the numerical simulation calculation area and the sealing condition of air curtain. Then set up physical model for wind pressure, multiply of hot pressure and the local hot pressure at the dinning room door of the air curtain air flow in CFD method. Through the numerical simulation for different jet velocity of the hot air curtain, analysis the temperature field, velocity field, heat loss,heat load parameter, etc. and demonstrate the energy saving effect, and provide reference basis for the selection of air curtain.

Abstract: To increase largely the performance of shaped charge, it is required to generate detonation velocity much higher than CJ velocity or detonation pressure much higher than CJ pressure of existing high explosives. One solution is the application of overdriven detonation phenomena. In this study, the effects of overdriven detonation in tungsten loaded high density explosive on the performance of shaped charge were demonstrated by experiments and numerical simulation. Sample shaped charge was composed of the inner layer tungsten loaded high density PBX and outer layer high velocity PBX. Concentration of tungsten powder in high density PBX was varied from 20 to 60% in mass. The pressure of overdriven detonation in inner layer PBX was measured by PMMA gauge, and was shown to be higher than 50GPa. The experimental results showed that the initial jet velocity and jet penetration velocity in target plates were largely increased by the effects of the overdriven detonation in tungsten loaded high density PBX.