The interior ballistics simulations for AGARD gun condition were carried out using the developed code of the solid / gas two-phase flow model, in order to numerically examine the initial temperature effects of solid propellant on the interior ballistics performances. The variation of the initial temperature of solid propellant leads to changes of the temperature difference between the initial temperature and the ignition temperature of the propellant, and the burning rate coefficient. The two conditions were examined individually in the present numerical analysis, particularly focusing on the fluctuations of differential pressure between the breech and the base. The temperature difference dominated the combustion wave speed, and the burning rate of the solid propellant decided the heat release rate in the burning region. In the ignition process of granular solid propellant, the pressure gradients were formed at the propagating combustion wave front, and the magnitude of the pressure gradient is supposed to depends on both the combustion wave speed and the heat release rate. The pressure gradients propelled forward the propellant grains, and then this movement of the grains caused a significant pressurization at the projectile base wall. The above process generated the strong negative differential pressure. The simulated results showed that the magnitude of the pressure gradient decided the strength of negative differential pressure. Therefore, the two conditions, temperature difference and the burning rate, were significant factors for the generation of negative differential pressure.
飛翔体加速装置等に用いられる固体発射薬の初期温度条件が薬室内部の差圧変動へ及ぼす影響を調べるため，AGARDモデルを解析対象とした固気二相燃焼流シミュレーションを行った。一般的に，発射薬の初期温度が変化すると初期温度から着火点までの温度差および燃焼速度が変化する。発射薬の着火に要するエネルギーの影響と燃焼速度の影響について個別に数値解析を行い，各条件による差圧履歴の変化について検討を行った。解析より，点火時に薬室内部を伝播する燃焼波面の圧力勾配によって発射薬粒子が前方に移動し，この固相体積の前進が飛翔体底面における圧力の急激な増加を引き起こすため，結果として燃焼波の圧力勾配が差圧変動の強さを決定付けていることがわかった。この圧力勾配の大きさは，着火エネルギーに依存する燃焼波の伝播速度と，燃焼速度に依存する燃焼領域のエネルギー供給速度のバランスで決まると考えることができる。
interior ballistics, solid propellant, two-phase flow, propellant initial temperature.