Aero-Intercept and Aero-Rendezvous of Winged Space Vehicles at Constant Altitude

有翼太空飛行器之等高度空中攔截與空中會合

陳彥勳(Yen-Hsun Chen) ； 洪祖昌(Zhu-Chang Hong) ； 陳正興(Jeng-Shing Chem)

《中國航空太空學會學刊》 28卷4期 (1996/12) Pp. 277-285

https://doi.org/10.6124/TAASRC.199612_28(4).02

摘要

本論文主要是探討在等高度極音速滑航（無推力）狀況之有翼太空飛行器氣動力佳能的最佳化，且建立當其初始相對航向角(initial relative heading anlge)爲零時的飛行包線。基於應用上的不同，本篇將探討兩種型式的飛行：第一種是氣動攔截(aero-intercept)，此型式因以攔截爲目的，故只需到達目的地，不須考慮終點之速度和接觸角度，唯爲了使飛行器保持在等高度，所以終點速度不能低於失速臨界速度，對於終點航向角就不必加以指定。第二種爲氣動會合(aero-rendezvous)，而會合因須滿足兩機接合之需要，所以終點位置以及速度之大小和方向均必須與有欲會合之目標一致。因此空中會合有比空中攔截更嚴格的終端條件。
爲了建立飛行包線，本篇使用座標旋轉法以簡化數值的運算。因爲空中爛截的終端航向角不必限制，故其飛行包線不論在何初始相對航向角均對於零經度軸上下對稱。然而空中會合的飛行包線只有當初始相對航向角爲零或180°時才上下對稱。在空中會合的飛行包線有兩不連續跳點(jump)產生，這是因此型的最佳軌道有”C”型與”S”型的轉換。然而不論攔截或會合的包線，其不連續區域均會因最大升阻比變小而增大，此爲氣動力不足而產生的現象。

關鍵字

氣動攔截 ； 氣動會合 ； 飛行包線

並列摘要

This paper presents the aerodynamic performance optimziation of a lifting space vehicle at constant altitude hypersonic coasting flight for aero-intercept and aero-rendezvous purposes with initial relative heading angle of 0°. For aero-intercept the purpose is only to intercept the target, so there is usually no necessity to specify the final velocity vector. But on the aero-rendezvous aspect, besides the final position, the final velocity vector (both magnitude and heading) must also be specified. Therefore, the aero-rendezvous problem has stronger final conditions than the aero-intercept. In this paper we use the coordinate sytem rotation technique to ease the numerical computation and save time. The two-point boundary-value problem resulted from variational formulation is solved by using the direct shooting method. The flight envelope is a function of two angles: the initial position angle and the initial velocity heading of the space vehicle, both are measured relative to the specified final position and velocity vector. Because the final velocity vector of aero-intercept is free, the aero-intercept envelope is symmetric with respect to the longitudinal axis for all initial relative heading angles. Then the aero-rendezvous envelope is symmetric with respect to the longitudinal axis only when its initial relative heading angle is 0° or 180°. There is a sudden change or jump at two points on the aero-rendezvous envelope. The jump will become larger when the altitude is higher or the maximum lift-to-drag ratio is smaller. The filght envelope then reduces to a curve segment due to the limitation of insufficient aerodynamic capapbility.

並列關鍵字

aero-intercept ； aero-rendezvous ； flight envelople