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.