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THE performance characteristics of various devices applicable for jet directional control, lift augmentation, and VTOL-STOL studied at the NACA Lewis Laboratory are discussed, including jet deflection devices applicable to the conventonal round nozzle and novel nozzle configurations. The results indicate that many of the deflection devices applicable to conventional nozzles can readily be used for directional control or lift augmentation. Other deflection devices, such as movable plug, internal flap, cylindrical thrust reverser, swiveled primary with fixed shroud, and 90 deg side-bleed nozzle, are limited in application to jet directional control or aircraft trim because the loss in axial thrust for a given deflection force is prohibitive or the maximum deflected force obtainable is limited.

BORON compounds offer a heat of combustion 40% greater than that of aircraft fuels in current use. Diborane and pentaborane have burned satisfactorily in turbojets, afterburners, and ramjets. But boron compounds leave troublesome deposits and they present supply, storage, and handling problems. This paper describes investigations into the use of boron hydrides as high-energy liquid fuel. Present results indicate that the ultimate fuel will be a boron-hydrogen-carbon compound. The author also discusses other high-energy fuels of magnesium, aluminum, beryllium, and boron. Magnesium has been found to be a top fuel for short-time high-thrust applications, because of its high combustion temperature.

The paper discusses the general lubrication problems associated with operation of high-output aircraft engines. Since the paper is concerned with two types of aircraft engines, namely, turbine and reciprocating, a natural division into two parts is made. Part I deals with the problems of turbine engines, and part II deals with the problems of reciprocating engines. In part I it is indicated that the choice of a lubricant is very difficult for the turbine engine particularly, because of the wide temperature range (from -67°F to approximately 400° F). Two solutions to the problem of proper choice of a lubricant are discussed, namely (1) the use of supplemental lubricants, and (2) the use of additive lubricants. Data are presented on supplemental lubricants including the various oxides of iron, molybdenum disulfide and graphite.

ENGINE-TEST results are presented for simulated altitude conditions using a displacer-piston combustion-chamber on a 5-in. by 7-in. single-cylinder compression-ignition engine operating at 2000 r.p.m. Comparison between maximum performance at altitude of the compression-ignition engine and a carburetor engine showed that the compression-ignition engine had a slight power advantage for the same conditions of inlet air. However, if the carburetor air is heated to prevent icing, the compression-ignition engine inducting the colder and more dense air of altitude will have a decided advantage over the carburetor engine. Analysis of the results for which the inlet-air temperature and pressure were varied independently indicates that maximum engine performance cannot be corrected reliably either on an inlet-air-density or weight-of-air-charge basis. Maximum engine power increases with inlet-air pressure and decreases with temperature very nearly as straight lines.