Influence of Ramjets’ water inflow on supercavity shape and cavitator drag characteristic

Water ramjets using outer water as an oxidizer have been demonstrated as a potential propulsion mode for underwater High Speed Supercavitating Vehicles (HSSVs) because of their higher energy density, power density, and specific impulse, but water flux changes the shapes of supercavity. To uncover the cavitator drag characteristics and the supercavity shape of HSSVs with water inflow for ramjets, supercavitation flows around a disk cavitator with inlet hole are studied using the homogenous model. By changing the water inflow in the range of 0–10 L/s through cavitators having different water inlet areas, a series of numerical simulations of supercavitation flows was performed. The water inflow flux of ramjets significantly influences the drag features of disk cavitators and the supercavity shape, but it has little influence on the slender ratio of supercavitaty. Furthermore, as the water inlet area increases, the drag coefficient of the cavitators’ front face decreases, but this increase does not influence the diameter of the supercavity’s maximum cross section and the drag coefficient of the entire cavitator significantly. In addition, with increasing water flux of the ramjet, both the drag coefficient of cavitators and the maximum diameter of supercavities decrease stably. This research will be helpful for layout optimization and supercavitaty scheme design of HSSVs with water inflow for ramjets.     

建筑垃圾再生材料路堤温度场分布规律分析

建筑垃圾再生材料作为一种新型高速公路路基填料其应用过程中路堤内部的温度分布特征尚不明确,本文依托西咸北环线高速公路工程,采用现场监测方法对建筑垃圾再生料路堤内部温度场分布规律开展了研究。研究表明:建筑垃圾再生材料路堤内部温度变化符合正弦函数变换规律,温度振幅随路堤深度增加呈指数函数变化,大气温度对路堤的影响仅限于路堤中上部。