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This paper reviews a recent internal study by Pratt & Whitney to define the optimum propulsion system characteristics for a commercial transport designed to fly at Mach 0.95. The impact on aircraft gross weight of propulsion cycle characteristics such as bypass ratio, overall pressure ratio, turbine temperature, nacelle weight, and drag as well as the important criteria of noise is reviewed. ...The impact on aircraft gross weight of propulsion cycle characteristics such as bypass ratio, overall pressure ratio, turbine temperature, nacelle weight, and drag as well as the important criteria of noise is reviewed.

An aircraft propulsion system for Mach .6 flight is being developed which utilizes two turboshaft engines driving a pusher propeller through driveshafts and a combining gearbox.

Several ramjet propulsion systems are evaluated for future Earth-to-orbit transportation designed for reduced operational cost, reduced loads on payloads, and increased flexibility of launch site and schedule.

The C-5A propulsion system installation is described and discussed. Induction system, exhaust system, and thrust reverser configurations define the general nacelle concepts.

This paper will identify some of the primary propulsion integration problems for high performance aircraft at transonic speeds, and demonstrate several methods for reducing or eliminating the undesirable characteristics, while enhancing configuration effectiveness.

A unique propulsion system is being developed for the Space Shuttle Orbiter utilizing airbreathing engines to provide a means for horizontal flight testing and ferrying the Orbiter within the contiguous United States. ...The airbreathing engine arrangement which has resulted, while employing conventional propulsion subsystems, still possesses installation problems because of the low ground clearance.

Studies recently completed for NASA show significant improvements in duct heating turbofans and low-bypass turbojets for an advanced supersonic transport. Dual-valve variable-cycle engines (VCE) prove to be noncompetitive; however, an emerging double-bypass dual-cycle VCE concept is reviewed which does indicate range improvements that are possible. It is 1985 technology and would require extensive development. Engine availability in the United States,as important to program success as technology or economics,is discussed. A fan derivative of an improved-technology Rolls Royce Olympus engine is also considered. An interesting case is developed showing that an Olympus fan derivative on a Douglas AST design offers an earlier U.S. SST possibility than heretofore thought possible. This might be important if airline pressure should mount as a result of overwhelming public demand for Concorde supersonic travel.

General aviation of the middle 1980's has been less than inspiring from a business viewpoint. Numerous aerodynamic innovations have matured, however, little progress has been made in powerplants. Although significant technology exists for powerplant design progress, low demand and product liability concerns have supressed implementation. The Merlyn design represents one of several present efforts to provide a particular technology to address specific needs in the aviation marketplace.

Continued performance demands make interceding attractive on single-engine turbosupar-charged applications. Intercooling permits power increases which yield significant speed improvements particularly at altitude. Attention paid to ducting as well as cooler sizing results in very effective installations.

The author discusses the ADAM II (Air Deflection and Modulation) propulsion system as it is applied to LTV propulsive wing airplane configurations which house all or part of their propulsion system within the wing surface. ...The author discusses the ADAM II (Air Deflection and Modulation) propulsion system as it is applied to LTV propulsive wing airplane configurations which house all or part of their propulsion system within the wing surface. Briefly mentioned are the original ADAM I configuration and its subsequent development to the present ADAM II, together with a discussion of the characteristics currently used for each of its components such as fan turbine set, gas generator, hot gas ducting, wing mounted turbofans, and mechanical cross shafting. ...The ADAM II concept is applicable to a full spectrum of subsonic aircraft and the propulsion system uses present day state-of-the-art technology which makes the feasibility of its development quite real.

Wide scope systems studies of V/STOL propulsion were conducted by GE, encompassing the total air vehicle design and its operation in lift, transition, cruise, and STOL modes. ...To determine VTOL propulsion requirements, the author explains the necessity for incorporating the entire air vehicle into the analysis. ...It is felt that the performance indicated necessary by these studies is now attainable by the propulsion industry.

The steps involved in design and development of the L-1011 propulsion system, with emphasis on maintenance aspects of the program, are summarized. System requirements, including maintainability and reliability, performance, and noise are reviewed. ...Major factors leading to determination of the propulsion system configuration are summarized and the rationale for meeting requirements of the various components leading to a well balanced propulsion system is presented. ...Major factors leading to determination of the propulsion system configuration are summarized and the rationale for meeting requirements of the various components leading to a well balanced propulsion system is presented. It is shown that the three-spool RB.211 engine satisfies requirements for minimum maintenance of the basic engine.

The characteristics of current space propulsion systems are reviewed, including performance, storability, restart, and throttling. Their limitations are discussed with emphasis in the area of long-term storage coupled with high performance.

Conventional flight between wing stall speed and 160 knots has met design objectives in terms of installed turbojet performance, compatibility of the convertible lift fan propulsion system, power requirements, stability and general handling qualities. Over thirty vertical lift-offs have demonstrated a thrust augmentation of nearly three with fan-derived control performance achieving desirable levels. ...Next flight test sequence will use both aircraft to simultaneously expand conventional flight envelope and explore transition flight through propulsion system conversion speed.

Propulsion system controls have been steadily increasing in complexity to meet the regulation and limiting requirements of current and future turbine engines. ...This requirement further increases the sensing, computational and regulation functions of the propulsion system control. In the past, electronic controls have played a subordinate role because of the severe turbine engine flight environment and the computational needs of the engine could usually be met by hydromechanical components. ...With this insight, more timely planning and execution of state-of-the-art advances in propulsion system control technology can be accomplished to meet the functionability, performance, and confidence goals of future propulsion system hardware.

Investigation into electric propulsion continues to be an area of hopeful research since the pioneering age of aviation. However, more recent global awareness of carbon emissions on the planet and the desire to create more efficient systems has reinvigorated new life into the field. ...Experimental studies on electric propulsion by virtue of asymmetrical electrodes, on a micro scale, have yielded potentially superior efficiency ratings when compared to currently adopted methods. ...This method of propulsion is unique and possesses several features that differentiate it from conventional methods of propulsion.

Two propulsion related drag correlation parameters have been developed. Existing or planned parametric jet aftbody drag data can therefore be reduced into a simple prediction technique for aircraft preliminary design studies. ...The drag due to the external nozzle geometry correlates with the average slope of the aftbody's area distribution (Integral Mean Slope), and the drag influence of the internal nozzle geometry/exhaust plume correlates with an effective plume inclination angle (Plume Correlation Parameter). The propulsion related drags of single, twin, and two-dimensional jet installations, and convergent, convergent-divergent, and plug nozzles are shown to correlate with the two parameters.

The Waste Management/Rocket Propulsion System appears capable of satisfying many propulsion requirements; for example, orbit change maneuvers, aerodynamic drag makeup, midcourse correction, terminal braking, and auxiliary and emergency propulsion. ...To date, spacecraft designers have considered life support systems and rocket propulsion systems as independent subsystems of a manned spacecraft. The Integrated Waste Management/Rocket Propulsion System concept developed by Rocket Research Corp. under NASA Contract NAS 1–6750, has demonstrated that human waste products can form a useful propellant ingredient and provide propulsion, as well as be an effective means of removing and sterilizing spacecraft waste. ...The Integrated Waste Management/Rocket Propulsion System concept developed by Rocket Research Corp. under NASA Contract NAS 1–6750, has demonstrated that human waste products can form a useful propellant ingredient and provide propulsion, as well as be an effective means of removing and sterilizing spacecraft waste.

The purpose of this paper is to identify some of the constraints imposed on an airplane propulsion system by transonic cruise speeds and to explore some ways to satisfy them. As the design Mach number of an airplane is increased above the 0.85 level toward 1.0, good airplane performance depends increasingly on careful tailoring of the propulsion installation and its integration into the overall configuration to establish a good compromise between drag, internal nacelle performance, and the practical considerations that produce an excellent airplane. ...As the design Mach number of an airplane is increased above the 0.85 level toward 1.0, good airplane performance depends increasingly on careful tailoring of the propulsion installation and its integration into the overall configuration to establish a good compromise between drag, internal nacelle performance, and the practical considerations that produce an excellent airplane.

Because of optics' inherent immunity to electromagnetic noise it offers considerable promise in improving the reliability of propulsion control systems. Future engine systems will be electronically controlled with no hydromechanical backup.