Research On The Mitigation Of Shock Wave Using Fine Water Mist

The ocean is rich in natural resources and has unique geographical advantages.It is essential for China to build a strong people's navy that can enhance the ability of marine control on the journey to a strong maritime nation.In the face of maritime disputes and the potential dangers of naval battles,improving the protection and vitality of warships has become an urgent problem to be solved.Modern anti-ship missiles and torpedoes can penetrate the outer panel into the chamber,which poses a serious threat to personnel and equipment.If we can absorb,block or transfer the huge energy generated by the explosion in a reliable and convenient way,we can increase the vitality of personnel and shipboard equipment,which is of great significance to ship protection.In the face of all kinds of fires,gas explosions,explosives and other threats,the advantages of fine water mist with its wide range of sources,low cost,environmental protection,and large specific heat capacity has become the focus of researchers.Theoretical and numerical simulation methods were used in this paper to study the mitigation of shock wave using fine water mist.The main research contents and conclusions were as follows:(1)Considering the evaporation,kinetic energy absorption and sensible heat absorption of the droplets,the relationship between the front-parameters and back-parameters of the plane shock wave was deduced.The relationship between the back-wave droplet velocity and parameters of the plane shock wave when the influence of shock wave temperature field on the droplets was neglected was deduced.The relationship between the mass of fine water mist swept through the unit time and parameters of the plane shock wave was deduced.By combining with the related equations of the shock tube flow parameters,the classical theory for solving shock tube flow parameters was improved,making it suitable for considering the effect of fine water mist on the plane shock wave.The shock wave pressure and wave velocity calculated from the theoretical formula were compared with the experimental data and the applicability and reliability of the formula were verified.(2)Based on the theoretical formulas deduced and the research results of relevant scholars,the kinetic energy absorption rate of droplets,the crushing energy absorption rate of droplets,the sensible heat energy absorption rate of droplets,and the latent heat energy absorption rate of droplets when the fine water mist acted on shock waves were analyzed.Sensible heat absorption was the main mechanism by which fine water mist weakens shock waves in the case of very small evaporation.(3)The numerical simulation model was established when the fine water mist acted on the shock wave.The pressure curve obtained by the numerical simulation was compared with the experimental data,and the applicability and reliability of the numerical simulation method were verified.(4)The numerical simulation method was used to study the effect of droplet diameter,mass concentration,initial velocity of droplet on the peak pressure of shock wave,back-wave droplet velocity,back-wave droplet temperature and evaporation rate of droplet under the same initial shock wave.Numerical simulation results indicated that when the droplets diameter of fine water mist was in the range of 50 ?m-500 ?m,the smaller the diameter was,the stronger the weakening effect of the shock wave was.When the diameter of fine water droplets was less than 500,the greater the mass concentration was,the stronger the shock weakening effect was;When the droplet diameter and mass concentration of the fine water mist were the same,the pressure of the shock wave can be weakened more when the initial velocity direction of the fine water droplets was opposite to the propagation direction of the shock wave.