The virial equation can well describe gas state at high temperature and pressure, but the difficulties in virial coefficient calculation limit the use of virial equation. Simple extended corresponding state principle(...The virial equation can well describe gas state at high temperature and pressure, but the difficulties in virial coefficient calculation limit the use of virial equation. Simple extended corresponding state principle(SE-CSP) is introduced in virial equation. Based on a corresponding state equation, including three characteristic parameters, an extended parameter is introduced to describe the second virial coefficient expressions of main products of propellant gas. The modified SE-CSP second virial coefficient expression was extrapolated based on the virial coefficients experimental temperature, and the second virial coefficients obtained are in good agreement with the experimental data at a low temperature and the theoretical values at high temperature. The maximum pressure in the closed bomb test was calculated with modified SE-CSP virial coefficient expressions with the calculated error of less than 2%, and the error was smaller than the result calculated with the reported values under the same calculation conditions. The modified SE-CSP virial coefficient expression provides a convenient and efficient method for practical virial coefficient calculation without resorting to complicated molecular model design and integral calculation.展开更多
针对当前等效全装药(Equivalent Full Charge,EFC)折算系数的国家军用标准预测值与实际测试结果差距较大的问题,基于热-化学烧蚀模型,研究不同工况下射击发数与EFC射击发数间的折算系数计算方法。射击一定发数后,假设身管内壁白层厚度...针对当前等效全装药(Equivalent Full Charge,EFC)折算系数的国家军用标准预测值与实际测试结果差距较大的问题,基于热-化学烧蚀模型,研究不同工况下射击发数与EFC射击发数间的折算系数计算方法。射击一定发数后,假设身管内壁白层厚度及成分随射击发数呈周期性变化,由质量扩散定律建立膛线起始部热-化学烧蚀量与火药燃气侵蚀性、内膛表面瞬态温度的关系。通过经典内弹道模型获得弹后空间火药燃气平均温度及内壁面强制对流换热系数,在考虑后效期高温燃气影响的基础上,建立身管内壁瞬态温度计算模型。以对内弹道过程有重要影响的射速、药量和药温为重点,计算不同射速、不同药号和不同药温下的身管内壁烧蚀量,并据此获得不同工况下的折算系数。研究发现,射速越快,装药质量越大,装药初始温度越高,单发射击造成的身管烧蚀越严重,其对应的EFC折算系数越大,其中强装药的EFC折算系数可达2.131。以某型155 mm火炮身管实弹射击数据为例,验证了新模型的合理性。展开更多
文摘The virial equation can well describe gas state at high temperature and pressure, but the difficulties in virial coefficient calculation limit the use of virial equation. Simple extended corresponding state principle(SE-CSP) is introduced in virial equation. Based on a corresponding state equation, including three characteristic parameters, an extended parameter is introduced to describe the second virial coefficient expressions of main products of propellant gas. The modified SE-CSP second virial coefficient expression was extrapolated based on the virial coefficients experimental temperature, and the second virial coefficients obtained are in good agreement with the experimental data at a low temperature and the theoretical values at high temperature. The maximum pressure in the closed bomb test was calculated with modified SE-CSP virial coefficient expressions with the calculated error of less than 2%, and the error was smaller than the result calculated with the reported values under the same calculation conditions. The modified SE-CSP virial coefficient expression provides a convenient and efficient method for practical virial coefficient calculation without resorting to complicated molecular model design and integral calculation.
文摘针对当前等效全装药(Equivalent Full Charge,EFC)折算系数的国家军用标准预测值与实际测试结果差距较大的问题,基于热-化学烧蚀模型,研究不同工况下射击发数与EFC射击发数间的折算系数计算方法。射击一定发数后,假设身管内壁白层厚度及成分随射击发数呈周期性变化,由质量扩散定律建立膛线起始部热-化学烧蚀量与火药燃气侵蚀性、内膛表面瞬态温度的关系。通过经典内弹道模型获得弹后空间火药燃气平均温度及内壁面强制对流换热系数,在考虑后效期高温燃气影响的基础上,建立身管内壁瞬态温度计算模型。以对内弹道过程有重要影响的射速、药量和药温为重点,计算不同射速、不同药号和不同药温下的身管内壁烧蚀量,并据此获得不同工况下的折算系数。研究发现,射速越快,装药质量越大,装药初始温度越高,单发射击造成的身管烧蚀越严重,其对应的EFC折算系数越大,其中强装药的EFC折算系数可达2.131。以某型155 mm火炮身管实弹射击数据为例,验证了新模型的合理性。
