Solid Fuel Stamping Extended Range Play Characteristics Research

Solid fuel ramjet has advantages of simple structure, high specific impulse and self-adapting. The use of solid fuel ramjet assisted range projectiles can greatly improve artillery range. The projectile has a high flying speed, which can shorten the whole ballistic flight time, increase the ability of penetration, and it has a good utilization prospect. This article is about the study on the ballistic performance of extended range projectile using solid fuel ramjet.For solid fuel ramjet working characteristics, a method which couples parts of solid fuel ramjet to performance prediction was given. The performance prediction of parts of solid fuel ramjet was coupled by solving the position of normal shock in the inlet. The method also increased the thermodynamic calculation with the equilibrium constant method in the combustion chamber calculation model, which was more quickly and simple compared to the previous method using the thermal difference calculation. This method also was applicable to the single mass propellant and composite propellant contained the C, H, O, N. This method can quickly and accurately calculate internal ballistic performance of solid fuel ramjet, thus to provide the basis for designing the structure of engine.Based on two-dimensional axisymmetrical steady-compressible N-S equations and the standard two-equations (k-ε) turbulence model, the internal and external flow field of a extended range projectile using solid fuel ramjet was calculated. The aerodynamic characteristics and internal and external flow field at different Mach number and was analysed. A method was given to calculate aerodynamic force by transforming integral of the surface pressure of the similar projectile whose shape is similar to the extended range projectile using solid fuel ramjet. The method can calculate aerodynamic force of the extended range projectile with the viscid characteristic method and the second-order shock expansion method. The calculation results were reliable and accurate with this method in the design condition.Based on the above studies, the particle trajectory model of extended range projectile was established to calculate the integration ballistic of internal ballistic and external ballistic, and the relationship between structural parameters and ballistic performance was revealed. For flying characteristics of the projectile, a method was given to design the extended range projectile using solid fuel ramjet by matching the thrust and drag. This method can be used to design the surface shape of extended range projectile and structure parameters of solid fuel ramjet at different flight altitude and speed. The calculation software related to the above function was developed. This software not only can estimate performance and aerodynamic force, simulate trajectory of extend range projectile, but also can help to design the ramjet. The software can meet the needs of the general scheme design of extend range projectile, effectively enhance the design ability and short the development cycle, thus to provide theoretical guidance and reference to the design and tests of extend range projectile using solid fuel ramjet.