四孔长方体发射药的形状函数计算及燃烧性能

Calculation of Shape Function and Combustion Performance of Four⁃hole Cuboid Gun Propellant

为研究四孔长方体发射药的燃烧性能,根据四孔长方体发射药的结构特征,建立四孔长方体发射药的燃烧物理模型,通过Maple软件得到其Ψ-Ζ、Γ-Ψ曲线。对比分析了相同弧厚及长宽比时,圆柱七孔发射药、圆柱单孔发射药与四孔长方体发射药的理论燃烧性能,同时研究了不同内外弧厚、长宽比及内孔径大小的四孔长方体发射药燃烧性能,并对其中的一种情况进行了实验验证。结果表明当长宽比大于1.5时,四孔长方体发射药具有良好地燃烧渐增性,且优于圆柱单孔发射药,劣于圆柱七孔发射药,但其分裂点相对于圆柱七孔发射药更加靠后;内外弧厚一致、长宽比为1.5~3、孔径为0.10~0.20 mm的四孔长方体发射药,具有相对较好的燃烧性能;实验结果能够较好地与理论分析结果相吻合,但由于发射药内孔位置的偏离以及尺寸一致性差,导致燃烧分裂点相比于理论计算要提前到达,因此可基于理论分析结果优化加工工艺,提高发射药的尺寸一致性及药孔分布的均匀性。

In order to investigate the combustion performance of four‐hole cuboid gun propellants,a combustion physical model was established according to the structural characteristics of four‐hole cuboid gun propellants.TheΨ‐ΖandΓ‐Ψcurves were obtained through the Maple software.The theoretical combustion properties of four‐hole cuboid gun propellants were compared with that of the cylindrical seven‐hole and single‐hole gun propellants under the same web size and length‐to‐diameter ratio.Meanwhile,the web size,length‐to‐diameter ratio and inner‐hole diameter were researched as the main factors to the theoretical combustion properties.The results demonstrated that the four‐hole cuboid gun propellant performed a good progressive com‐bustion property when the length‐to‐diameter ratio was higher than 1.5,which was better than the cylindrical single‐hole gun propellants.Although the four‐hole cuboid gun propellant performed a worse combustion property than the cylindrical seven‐hole gun propellant,it displayed the combustion split points in the latter point.Meanwhile,the four‐hole cuboid gun propellant had a better progressive combustion property when the inner web size was the same as the outer,the length‐to‐diameter ratio was in the range from 1.5 to 3,and the inner‐hole diameter was in the range from 0.10 mm to 0.20 mm.The experimental results agreed well with the theoretical analysis results,but the moulding process leaded to the certain deviation of inner hole,resulting in the splitting point reached in advance.