基于局部敏感性的平衡场长影响因素分析

平衡场长是民用飞机设计与使用中的重要技术指标之一,其长短对民用飞机的经济性、安全性和通用性均有显著的影响,同时也是确定飞机决策速度的基础,因而,研究平衡场长具有重要意义。介绍平衡场长的概念、计算方法及它与决策速度之间的关系,列举三种敏感性分析理论;以某型民用飞机为例,研究起飞质量、机场高度、风速、温度、跑道坡度等因素对平衡场长的影响,利用上述敏感性分析方法评估不同因素对平衡场长的敏感程度。结果表明:平衡场长和决策速度随着起飞质量、机场高度、顺风风速、温度的增加而增加,随逆风风速的增加而减小;跑道坡度对平衡场长的影响几乎可以忽略;三种敏感性分析方法所得参数的正负相关性一致,五个变量对平衡场长的敏感性排序为:起飞质量风速机场高度温度跑道坡度。

Analysis on the influence factors of balanced field length based on local sensitivity

Balance field length is one of the important technical indexes in civil aircraft design and operation, and it has a significant impaction on civil aircraft economy, safety and universality, and also is the basis of determining the aircraft decision speed. This paper does introduce the concept and calculation method of balance field length and the relation between balance field length and decision speed, and list three sensitivity analysis theories. Taking a civil aircraft as an example, research the effects of takeoff weight, airport height, wind speed, temperature, runway slope and other factors on the balance field length, evaluate the sensitivity of different factors to balance field length with the three analysis theories. The results show that the length of balance field and the decision speed increase with the increase of takeoff weight, airport height, tailwind speed and temperature, decrease with the increase of headwind speed. The effect of runway slope on the balance field length is negligible. The positive and negative correlations of those parameters obtained by the three sensitivity analysis methods are consistent, and the sensitivity of the five variables to the balance field length are ranked as follow: takeoff weight>wind speed>airport height>temperature>runway slope.