Effects of centrifugal force and glide distance on the flight performance of HCV

The flight performance of hypersonic cruise vehicles (HCVs), a competitive focus of international aerospace technologies in the 21st century, can be measured by a ratio of the initial boost mass to the generalized payload. A coupling frame to analyze the performance was established in Ref.[1]. Under the frame, two important effects, namely the centrifugal force and glide distance, have been further taken into account in this article. It was shown quantitatively that for a given distance, the first important factor to affect the flight performance of HCVs is the cruise speed, the second is the lift-to-drag ratio, and the third is the specific impulse of the cruise engine. As a flight distance increases, the performance of a rocket-based HCV, greatly improved due to the centrifugal force and glide distance taken into account, is significantly superior to the classical minimum-energy trajectory from short-middle to long range. A hypersonic air-breathing ramjet, though its specific impulse much higher than that of a rocket engine, is not so good as the latter in terms of the cruise speed range and lift-to-drag ratio. It is concluded that rocket-based HCVs flying at the optimal speed are a very competitive choice at the current stage.