火箭发射前后3.5 h内高空风差异特征及预报

利用2014年12月—2020年12月时间间隔为3.5 h的高空风实况分析火箭发射前后3.5 h内高空风差异, 并利用WRF模式和火箭发射前3 h高空风建立火箭发射后0.5 h高空风预报模型, 结果表明:火箭发射前后3.5 h内高空风速、风向差异特征, 与高度、季节及火箭发射前3 h平均高空风速有关。高空风最大风速偏差为-24.00~26.00 m·s-1, 风速偏差在10 m·s-1以内达三分之二, 且主要出现在对流层中高层6.5 km, 11.5 km)高度内;最大风向绝对偏差范围为10.00°~180°, 主要集中在30°, 60°)范围及对流层中低层1.5 km, 6.5 km)高度内。火箭发射前后3.5 h内高空风速平均绝对偏差随火箭发射前3 h高空风速平均值增大呈增大趋势, 风速相对误差绝对值和风向绝对偏差则表现为减小趋势, 说明高空风强时, 风向不易发生短时变化;火箭发射前后3.5 h内高空风差异随季节变化与高空风的季节特征有关。利用火箭发射后0.5 h高空风预报模型, 有助于降低火箭飞行风险。

Upper Wind Difference Characteristics and Forecast Within 3.5 Hours Before and After Rocket Launch

The upper wind has a major impact on the safety of the launch vehicle, and the wind speed 3 hours before launching is a determinant for the eventual schedule. If the maximum aerodynamic load generated by the upper wind does not exceed the threshold, the rocket can be launched as planned, otherwise it will be considered to postpone the launch. The deviation of the upper wind 3 hours before and at the launch time should be investigated. Taking the upper wind dataset with an interval of 3.5 hours (December 2014 to December 2020) to analyze the wind difference, and a forecast model for the wind of 0.5 hours after the launch is established using WRF model and the wind data of 3 hours before the launch. It shows that the characteristics of upper wind speed and direction difference within 3.5 hours are related to altitude, season, and the average upper wind speed. Although the maximum wind speed deviation range is -24.00-26.00 m·s-1, for two-thirds of the cases the deviation is within 10 m·s-1, which mainly occur in the middle and upper troposphere with altitude of 6.5 km, 11.5 km). The absolute value of the maximum wind direction deviation range is 10.00°-180°, mainly in the 30°, 60°) interval, and this mostly occurs in the middle and lower troposphere with altitude of 1.5 km, 6.5 km). The average absolute deviation of the upper wind speed within 3.5 hours shows an increasing trend with the increase of average upper wind speed 3 hours before the launch, but the relative error and the wind direction deviation decreases, indicating that when the upper wind is strong, the wind direction is less prone to short-term changes. The upper wind deviation within 3.5 hours varies with the seasons, for example, the absolute deviation of winter wind speed is greater than that of summer, but the absolute deviation of wind direction in winter is smaller than that of summer. Using the forecast model results of wind 0.5 hours after the launch can help to avoid the risk of rocket launch in advance.