New Calculation Method for the Delay Time of the Heat Conduction Delay Element

In order to ensure the safety and reliability of weapons, it is very important to grasp the influence of the inside and outside diameters of the shell on the delay time. In this paper, a fluid–solid coupling model is established for a metal baffle-type delay element with a silicon-based delay composition. The combustion flow field of the delay element with the inside diameter of 3, 4, and 5 mm is simulated by the Star-CD software. Then a new method is proposed to calculate the delay time of the heat conduction delay element. The influence of the internal and external diameters on the delay time of the thermal conduction delay element is studied. The results show that the temperature of the ignition composition gradually increases due to the heat conductivity of the metal baffle after burning of the delay composition, and the highest temperature is reached at the centre of the ignition composition. The influence of the size of the inside and outside diameters on the delay time has a critical equilibrium point, which may be related to the balance between the combustion heat increment and the heat loss.