Parameteric investigation on ignition overpressure mitigation performance of rocket by water mist

To research the mitigation performance of rocket ignition overpressure by water mist layer, the theory of plane wave propagation in different medium was applied to expore the mechanism for ignition overpressure mitigation by water mist layer. And, main influential factors of ignition overpressure mitigation performance were obtained from theory analysis. Furthermore, the influence rules of the factors on the mitigation performance were studied by numerical computation and the proper value ranges of influential factor under the conditions of rocket safety launching were given. At last, the parameter levels of influential factors for numerical computation cases were arranged by the uniform design. Meanwhile, the parametric model of the influential factors to the mitigation performance was built by regression, and the mitigation efficiency was optimized. The numerical results show that the main influential factors include water droplets diameter, water mist volume fraction and water mist layer thickness. And, there are two different mitigation mechanisms between water droplet and ignition pressure pulse which are closely related to droplet diameter. In addition, there is a parametric model of the influential factors to the mitigation performance when the influential factors falls within some value ranges, and fiducially probability of the model is not less than 95%.