Venting Analysis of the Payload Fairing of Korea Space Launch Vehicle II.

Our study involved an investigation of the venting analysis of payload fairing of Korea Space Launch Vehicle II with vent valves. Two types of vent valves with a spring-loaded door were developed for a payload adapter and compartments of Korea Space Launch Vehicle II. First, the performance of the vent valves was evaluated through three-axis random vibration tests and flow tests. Structural robustness of the vent valves was validated through random vibration tests. Flow characteristics were investigated through flow tests. The cracking pressure of the vent valves for the payload adapter was in the range of 74-86 Pa, whereas the cracking pressure of the vent valves for compartment was in the range of 384-447 Pa. The results of flow tests were used to determine valve models of the vent valves for the venting analysis. Subsequently, venting analysis was conducted to predict the maximum pressure difference and pressure drop rate of payload fairing, and the results were compared with those of other space launch vehicles. The maximum values of the pressure difference were -5.34 and 1.27 kPa. The maximum pressure drop rate was 4.68 kPa/s. The values were lower than the maximum values of other space launch vehicles. Consequently, the vent valves were suitable for Korea Space Launch Vehicle II. [ABSTRACT FROM AUTHOR]