WRIGHT RESEARCH AND DEVELOPMENT CENTER WRIGHT-PATTERSON AFB United States
Over the past few years, interest in manned hypersonic flight has increased significantly. System studies historically have utilized ramjet power for high supersoniclow hypersonic speeds and supersonic combustion ramjets scramjets at higher speeds. The drawback of these types of propulsion devices is their inability to perform at takeoff and relatively low speeds. Therefore, for relatively low speed operation Mach 0-3, a third form of propulsion is required. The turbine engine has typically been chosen for this role. The disadvantages of a three mode propulsion system turbojet-ramjet-scramjet are the complexity, weight and costs which accompany it. Inlet and exhaust geometry variations required for proper integration play a major role. Propulsion weight is a key factor to maximize vehicle capability. When a propulsion device is not being utilized, it is dead weight to the aircraft system. Therefore, for reasons of simplicity, reduced system weight, and cost, it seems prudent to minimize the number of propulsion mode transitions required.
Hypersonic Combined Cycle Propulsion Panel Symposium, 28 May 1990, 01 Jun 1990, This article is from ADA253867.