Search

The aerodynamic characteristics of a water entry projectile is studied. The aerodynamic coefficients at different Mach numbers and different attack angles are given through CFD numerical simulation, and the stability analysis is carried out. The results show that the projectile with the current shape meets the static stability requirements. Based on the aerodynamic coefficients obtained, the projectile flight trajectory equation is established to obtain the trajectory at different emissive angles. Finally, the trajectory parameters with the range of 5 km were used as the initial conditions for the simulation of high-speed water entry projectile, and the process of projectile entry with small angle was simulated. The simulation results show that the projectile sails smoothly when entering the water, the trajectory is straight, there is no ricochet phenomenon, which has a good water entry stability.

Large caliber naval gun weapon system in sustained and rapid firing process, produced high temperature and high pressure gas will form pulsed high temperature flow in barrel, causing the barrel being heated and cooled sharply and then being in bad environment, affecting the life of the barrel. The research object of this paper is based on 155mm naval gun, to utilize the theories of fluid mechanics and heat transfer and use ANSYS-CFX software, to simulate the heat response of the gun’s rifling original portion under interlayer active cooling, and to analyse the effects of structure parameters of interlayer cooling system and flowing parameters of cooling liquid on cooling performance using the principle of heat transfer enhancement, providing guidance for the optimization of the structure of the interlayer cooling system.

In order to study the dynamic changes of the internal flow field physical quantities in the hydraulic buffer of a special equipment, based on the Computational Fluid Dynamics (CFD), a three-dimensional incompressible and viscous model under unsteady condition is created. The model keeps the control rod of varying diameter and non-working chamber cover, simulates the turbulent in the flow field of the hydraulic buffer of the special equipment with dynamic meshing technology. From the results, the distributions of velocity in flow field and pressure in chamber are got. It shows that there are negative pressure areas in the non-working chamber and that will lead to cavitation. The results give us a great reference to improve the structure of hydraulic buffer.