Research On Test Method For Quasi-Dynamic Burning Rate Of Solid Propellant

The burning rate of the solid propellant is one of the main interior ballistic parameters of the solid motor, and also is one of the main technical indexes which in needs of strictly control during the formula design and production process of the propellant. Such parameters as burning rate-pressure index and burning rate-temperature sensitive coefficient are two main technical indexes indicating the combustion performance of the solid propellant, which will be measured during the propellant research and production process. At present, some common burning rate test methods used both at home and abroad exist some problems, such as low test efficiency, and high cost, and the distorted results.According to the defects of the Grubbs rule in the national military standard when eliminating the abnormal data of the burning rate, this paper analyzes and compares the Grubbs rule and the t test criteria, and it finds out that the t test criteria can not only eliminate what the Grubbs rule can eliminate, but also what the Grubbs rule cannot, which is said that the t test criteria is better than the Grubbs rule. Based on the t test criteria, the paper proposes an improved burning rate data selection algorithm. The original algorithm can only eliminate an abnormal data one time, and the improved one can eliminate two abnormal data at most, which improves the efficiency and the precision.According to the problems existing in the current test methods of the solid propellant, the paper proposed a new quasi-dynamic burning rate test method based on the multi-target-line test technique. Compared with the existing static test methods, this method can reflect the dynamic changes of the burning rate more actually. Even one test with a small dose of the propellant can evaluate the combustion performance of the tested propellant in the corresponding change ranges of the pressure and temperature. In the propellant production process, this method is a kind of fast, efficient and quasi-dynamic test method, which plays an important role in guiding and fixing the formula and production technology of the propellant.The multi-target-line quasi-dynamic burning rate test method is still in the early stage of study, and this method has not been verified by practice. The data selection algorithm based on t test criteria would be improved to decrease their time complexity in our further work.