低温燃气弹射内弹道影响因素的数值研究

Numerical study on factors of interior ballistic for low-temperature gas-ejection

针对某低温燃气式弹射装置,建立简化二次燃烧物理模型,采用重整化群k-ε湍流模型模拟流场流动、以有限速率/涡耗散燃烧模型模拟气相燃烧、以域动分层法动网格更新技术模拟导弹运动,数值分析得到了发射筒内载荷与内弹道特性.结果表明:在满足内弹道设计要求的条件下,燃气发生器喷管入口总温包络区间为0.538~1.231,且随着总温的增加,二次反应时间和导弹出筒时间减小,导弹出筒速度增加;发射筒内氧气质量分数包络区间为0.07~0.30,且随着氧气质量分数的增加,二次反应发生时间和导弹出筒时间提前,导弹出筒速度增加.研究结果可为低温燃气式弹射内弹道分析和结构设计提供理论基础.

Regarding a low-temperature gas ejection mechanism,a simplified physical model of the secondary combustion was established,a renormalization group k-ε turbulence model was adopted to simulate the flow-field,and a finite rate/eddy dissipation model was used to simulate the gas phase combustion,meanwhile a dynamic mesh update method was employed to update the missile movement;the launch canister within the load and the interior ballistic properties were obtained through numerical analysis.Results show that：if the interior ballistic design condition is met,the range of the total temperature in the entrance section of the nozzle of gas generator is 0.538-1.231,and the time of secondary reaction and the time out of the barrel decreases with the rise of the total temperature,and the exit velocity increases accordingly.The range of the oxygen mass fraction of the launch canister is 0.07-0.30,and the begin time of secondary reaction and out of the canister of time decreases with the increase of the oxygen mass fraction,and the exit velocity increases with the increase of the oxygen mass fraction.Research results can be used as a reference for the interior ballistic and device structure.