英语翻译英译汉,不要图片形式,公式不必翻译The only unknown remaining is the value of S,the percentage of leading-edge suction actually attained by the wing at the flight condition in question.S depends largely upon the leading-edge r
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英语翻译英译汉,不要图片形式,公式不必翻译The only unknown remaining is the value of S,the percentage of leading-edge suction actually attained by the wing at the flight condition in question.S depends largely upon the leading-edge r
英语翻译
英译汉,不要图片形式,公式不必翻译
The only unknown remaining is the value of S,the percentage of leading-edge suction actually attained by the wing at the flight condition in question.S depends largely upon the leading-edge radius,and is also affected by the sweep and other geometric parameters.
S is also a strong function of the wing design lift coefficient and the actual lift coefficient.For any wing,the value of S is at a maximum when the wing is operating at the design lift coefficient.For most wins,S equals approximately 0.9 when operating at design lift coefficient.
For a subsonic wing with large leading-edge radius and moderate sweep,the value of S will change vary little with lift coefficient until the wing is near the stall angle of attack.For the thin,swept wings typical in supersonic aircraft,the value of S can change substantially with lift coefficient.A wing with an S of 0.9 at its design lift coefficient of 0.5 may have an S value less than 0.3 at a lift coefficient of 1.0.
Proper calculation of S for an actual wing is complex.An empirical approach may be used during conceptual design.Figure 12.37 provides a first order estimate of the percent of leading-edge suction for a typical supersonic aircraft’s wing,given the actual lift coefficient and the design lift coefficient (this determines which curve to use).Note that this chart assumes a well-designed wing,and at some later date the aerodynamics department must optimize the twist and camber to attain these values.
From Fig.12.37 the leading-edge suction at various lift coefficients can be estimated.This allows adding curves Fig.12.36.that represent the estimated.
必须通顺,想用翻译软件糊弄的就不要来凑数了
英语翻译英译汉,不要图片形式,公式不必翻译The only unknown remaining is the value of S,the percentage of leading-edge suction actually attained by the wing at the flight condition in question.S depends largely upon the leading-edge r
现在唯一不知道的就是S的值,即问题中所讨论的飞行器在飞行过程中机翼所获得的前缘吸力的百分比.S的值主要取决于前缘半径,并且还受后掠角和其他几何参数的影响.
S同时也是理论升力系数和实际升力系数的函数.对于任何一个机翼,S的值都是在机翼在最大理论升力系数时测量时达到最大.对于大多数飞机,当在理论升力系数的情况下飞行时,s的值约等于0.9.
对于具有大的前缘半径和中等后掠的亚音速翼型来说,当机翼接近失速迎角时,S值的变化和升力系数的相关性就不大了.但对于超音速飞行器中薄且有大后掠角的翼型来说,s值大体上是随着升力系数的变化而变化.对于一个当升力系数为0.5时S值可以达到0.9的机翼来说,当升力系数为1.0时,s值可能小于0.3.
正确计算实体机翼的S值非常是复杂的.一种经验法可以在概念设计时应用.图12.37提供了典型超音速翼型前缘吸力百分比的第一阶估计值,并给出了理论升力系数和实际升力系数(它将决定使用曲线的选择)注意,图形的得出是基于机翼是精心设计的前提,日后空气动力学部门必须优化扭转和弯曲已获得这些参数值.
根据图12.37,在不同升力系数下的前缘吸力可以估计.这使得在图12.36中可以加入代表估计值的曲线.