The interior ballistics simulations were carried out using the developed codes of the lumped parameter method and the solid / gas two-phase flow model for two-dimensional axisymmetric calculation, in order to reproduce the combustion process of the granular solid propellant in the chamber of projectile accelerator. Predicted results for AGARD gun condition by the lumped parameter method and two-dimensional axisymmetric calculation code using the representative particle method were compared with the results of the other codes for validation, and were in good agreement with that of the other codes. The predicted histories of the breech pressure and projectile muzzle velocities well agreed between the lumped parameter method and two-dimensional axisymmetric calculation codes, but there was clear difference in these histories of differential pressure since the pressure distribution in the two-dimensional axisymmetric simulation are quite different from the assumption in the Lagrange pressure gradient model of the lumped parameter method. Two-dimensional axisymmetric calculation predicted that the projectile base pressure rises and the differential pressure takes negative value in the ignition stage due to the movement of solid propellant grains. The predictive capability and effectiveness of solid / gas two-phase flow simulation for interior ballistics events, where the large distribution of solid phase volume exists, were shown by the simulated results.
固体発射薬を用いた飛翔体加速装置薬室内部における燃焼過程を再現するため，集中パラメータ手法の計算コードおよび代表粒子を用いた二次元軸対称の固気二相流計算コードを作成し数値計算を行った。標準的なAGARDモデルの条件に基づいた計算を行い，計算結果を他の計算コードの結果と比較して計算モデルの検証を行った。集中パラメータ手法，二次元軸対称計算の両コードとも他のコードによる計算結果と近い値を示した。また，最大砲尾圧と飛翔体出口速度に関して集中パラメータ手法の計算と二次元軸対称計算の結果に大きな差異は生じなかったが，薬室内部の差圧履歴に明白な差異が生じた。これは二次元軸対称計算における薬室内部の発射薬分布が集中パラメータ手法で用いる単純化の仮定と大きく異なっていたためである。二次元軸対称の固気二相流計算は固相粒子の移動の影響により初期において弾底圧が砲尾圧を上回り差圧履歴に負の値が生じることを予測し，固相体積分率に分布を生じる複雑な砲内現象の再現に対する固気二相流計算手法の有効性が示された。
Interior ballistics, Solid propellant, Two-phase flow, AGARD gun.