Study On Response Of Vertical Launching Missile Under Ground Wind Load

Surface wind generally refers to air flows from the inner surface to 150 m height range. Surface wind model may be composed of the average wind and fluctuating wind. Corresponding, missiles or launch cylinder of wind load response can also consist of average wind response and fluctuating wind response. Average wind response only considers static response of downwind but fluctuating wind response should be considered wind-induced response of downwind and cross wind. When the wind speed reaches local basic wind pressure, surface wind will have a significant impact on missile launch. This article bases on that using self’s strategic missile systems analyze what influence average wind response and fluctuating wind response have on missile launch process. The finding and conclusion of this study included:1. Set up the strategic missile weapon system model that includes 3D models, flow field region meshing and multi-body dynamics model.2. When the missile is erected on the ground in the outgoing state and the wind velocity blow direction perpendicular to the vehicle body, the static stability of missile-launch vehicle system which is in the downwind direction is the worst. When the safety factor ? ?1 2n? ?min n?, n? is greater than 1, launch vehicle system is in the stable situation.3. Missile having leaving the launch cylinder, when the vertical wind blow to the vehicle body, launch equipment’ static stability in the downwind direction is the worst. When the safety factor ? ?1 2n? ?min n?, n? is greater than 1, launch equipment is in the stable situation.4. According to comparative analog spectrum and target spectrum of the fluctuating wind, we can know that this article based on MATLAB programming that is preparation of harmonic synthesis can simulate well the fluctuating wind.5. Considering the influence of average wind on the missile launch process. When the missile and launch cylinder are in the process of launching, with the increase of wind speed on the four launch sites, their displacement of the center of the mass are also increasing.Missile erected on the ground in the outgoing state, when the wind speed parallel to the direction of the vehicle body, the launch cylinder’s displacing magnitude are about 10-2m ~ 10-1m; when the wind velocity blow direction perpendicular to the vehicle body, launching vehicle will do vibration or be blown down. Missile in the process of the cylinder, when the wind speed is parallel or perpendicular to the vehicle body, the displacing magnitude of the launch cylinder’s center of mass and the missile’s center of mass will both about 10-2m. After the missile leaving the launch cylinder, when the wind speed is parallel to the vehicle body, the displacing magnitude of the launch cylinder’s center of mass will be about 10-3m; when the wind speed is perpendicular to vehicle body, launchers will be blown down when the wind speed is greater than 21.91 m/s and the displacing magnitude of the missile’s center of mass will be about 10-1m.6. Considering the impact of fluctuating wind on the missile launch process. When missiles and launch cylinder are in the outgoing state, with the two launching site’s wind velocity increasing, their displacing magnitude of the center of the mass have also been increased in the downwind and in the crosswind. But their vibration frequency is not high.Missile erected on the ground in the outgoing state, when the wind is in the direction that parallels to the vehicle body, the launch cylinder’s displacing magnitude on the B launch will be 10-1m and 10-3m in the downwind and in the cross-wind; the launch cylinder’s displacing magnitude on the D launch will have been blown down both in the downwind and in the cross-wind. Besides, the value obtained by the harmonic synthesis of the same height of the wind is greater than the height of the wind through the same exponential value obtained.Missile in the process of the cylinder, when the wind is in the direction that parallels to the vehicle body, the displacing magnitude of the launch cylinder’s center of mass will be 10-2m and 10-3m in the downwind and in the cross-wind; the displacing magnitude of the missile’s center of mass will be 10-2m and 10-4m in the downwind and in the cross-wind. When the wind velocity blow direction perpendicular to the vehicle body, the displacing magnitude of the launch cylinder’s center of mass will be both 10-2m in the downwind and in the cross-wind; the displacing magnitude of the missile’s center of mass will be 10-2m and 10-3m in the downwind and in the cross-wind.Missile having leaving the launch cylinder, when the wind velocity blow direction perpendicular to the vehicle body, the displacing magnitude of the launch cylinder’s center of mass will be 10-3m and 10-4m in the downwind and in the cross-wind. When the wind velocity blow direction perpendicular to the vehicle body, the displacing magnitude of the launch cylinder’s center of mass will be 10-4m and 10-3m in the downwind and in the cross-wind; the displacing magnitude of the missile’s center of mass will be 10-1m and 10-5m in the downwind and in the cross-wind.