Experimental Research on the Temperature Equilibration Time of Typical Ammunitions

Abstract

The propellant temperature is one of the critical effects on the combustion speed of the ammunitions, and can affect the interior ballistic performance of guns. To obtain the temperature equilibration time of the charge in the ammunition temperature test, a group of experiments were carried on by testing a variety of typical ammunitions with different calibers in service. The ammunitions were modified, and a multi-channel temperature acquisition system was built to measure the internal temperature of the charge during the heating and cooling processes of the ammunition heat preservation test at the shooting range. Then, the concept of the thermal center and the calculation method of the temperature equilibration time were introduced. The equilibrium time of 12 kinds of propellants for 4 heating/cooling conditions was obtained based on the experimental data. Research results show that the heat transfer rate from the outside to the inside of the ammunition is getting slower, and the temperature equilibration time becomes longer. The temperature equilibration time of the 12 kinds of ammunitions in our experiment is no more than 26 hours, the temperature equilibration time is greater for the ammunition with a larger diameter generally, and the equilibration time of the small-caliber ammunition is only 7 h-8 h in this experiment. Besides, temperature equilibration time of the ammunition is decreased caused by the igniter tube in the charge center and the hollow combustible paper tube. It is concluded that the temperature equilibration time of the ammunition in the shooting range test can be greatly shortened compared with the temperature equilibration time specified by the current national military standard, which can improve the efficiency of the shooting range test.