单推-3单组元发动机低温起动过程仿真分析OA

Focusing on the low-temperature start-up process of the DT-3 monopropellant engine,a propellant phase change decomposition model and a corresponding catalyst bed model were established based on spot plate testing data and the propellant evaporation process.A simulation model reflecting the low-temperature start-up process of the DT-3 monopropellant engine was developed on this basis.Simulation results showed good agreement with low-temperature start-up test results for the 40 N,60 N,and 300 N DT-3 monopropellant engines,with deviations of chamber pressure start-up peak and peak time from the test values not exceeding 15%.This model was used to perform numerical simulations of the low-temperature start-up process for DT-3 monopropellant engines with different initial catalyst bed temperatures,bed loads,and catalyst bed structural dimensions.Results indicate that reducing the initial catalyst bed temperature from 0℃to-30℃increased the start-up peak by 3.71 times and delayed the peak time by 45 ms.Increasing the relative bed load from 1 to 1.56 raised the ratio of the start-up peak to the steady-state value by 1.15 times,with minimal delay in peak time.When the initial catalyst bed temperature and bed load were the same,increasing the catalyst bed structure size resulted in a larger ratio of start-up peak to steady-state value and a delayed peak time.Compared to the 40 N and 60 N monopropellant engines,the 300 N monopropellant engine presents a higher risk during low-temperature start-up process due to its higher bed load and larger catalyst bed structural dimensions.