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National advisory committee for aeronautics
512
I~OOIC REVIEWS.
[J. h-. 1.
The models of the XNzY-I and FqB-z airplanes gave good approximations to the spinning characteristics of the airplanes, in both steady spins and recoveries. Since these models were scaled from somewhat similar biplanes, no conclusions are drawn as to the reliability of model results in general. Report No. 560, A Simplified Application of the Method of Operators to the Calculation of Disturbed Motions of an Airplane, by Robert T. Jones. 13 pages, diagrams, 23 X 29 ems. Washington, Superintendent Price ten cents. of Documents, 1936. A simplified treatment of the application of Heaviside’s operational methods to problems of airplane dynamics is given. Certain graphical methods and logarithmic formulas that lessen the amount of computation involved are explained. The problem of representing a gust disturbance or control manipulation is taken up and it is pointed out that in certain cases arbitrary control manipulations may be dealt with as though they imposed specific constraints on the airplane, thus avoiding the necessity of any integration whatever. The application of the calculations described in the text is illustrated by several examples chosen to show the use of the methods and the practicability of the graphical and logarithmic computations described. Report No. 561. Effect of Nozzle Design on Fuel Spray and Flame Formation in a High-Speed Compression-Ignition Engine, by A. M. Rothrock 12 pages, plates, 23 X 29 ems. Washington, and C. D. Waldron. Superintendent of Documents, 1936. Price ten cents. Fuel was injected from different types of injection nozzles into the combustion chamber of the N. A. C. A. combustion apparatus, operated as a compressionignition engine; high-speed motion pictures were taken at the rate of 2,200 frames per second of the fuel sprays and the combustion. Single-orifice nozzles of o-.008-, o.ozo-, and 0.040~inch diameter, and multiorifice nozzles having 2, 6, and 16 Nozzles having impinging jets and slit orifices were also orifices were tested. included. The photographs indicate that the rate of vapor diffusion from the spray is comparatively slow and that this slow rate of diffusion for combustion chambers with little or no air flow prevents the compression-ignition engine, with the present methods of fuel injection, from giving the high performance inherent in the high compression ratios. The sprays from multiorifice nozzles destroyed the air movement to a greater extent than did those from single-orifice nozzles. It is concluded that high performance cannot be realized until the methods of distributing the fuel are improved by means of the injection-nozzle design, air flow, or both. CONSTELLATIOKS. Prepared by the Department of Astronomy of The Franklin Institute. 32 pages, illustrations, 15.5 X 23 ems. Philadelphia, Institute, 1936. Price thirty-five cents. To those who have recently visited the Fels Planetarium in Philadelphia, this booklet is not unfamiliar, but for the information of others who have not visited here it is a revelation of the universe in which we are living. Star maps are shown,
I~OOIC REVIEWS.
[J. h-. 1.
The models of the XNzY-I and FqB-z airplanes gave good approximations to the spinning characteristics of the airplanes, in both steady spins and recoveries. Since these models were scaled from somewhat similar biplanes, no conclusions are drawn as to the reliability of model results in general. Report No. 560, A Simplified Application of the Method of Operators to the Calculation of Disturbed Motions of an Airplane, by Robert T. Jones. 13 pages, diagrams, 23 X 29 ems. Washington, Superintendent Price ten cents. of Documents, 1936. A simplified treatment of the application of Heaviside’s operational methods to problems of airplane dynamics is given. Certain graphical methods and logarithmic formulas that lessen the amount of computation involved are explained. The problem of representing a gust disturbance or control manipulation is taken up and it is pointed out that in certain cases arbitrary control manipulations may be dealt with as though they imposed specific constraints on the airplane, thus avoiding the necessity of any integration whatever. The application of the calculations described in the text is illustrated by several examples chosen to show the use of the methods and the practicability of the graphical and logarithmic computations described. Report No. 561. Effect of Nozzle Design on Fuel Spray and Flame Formation in a High-Speed Compression-Ignition Engine, by A. M. Rothrock 12 pages, plates, 23 X 29 ems. Washington, and C. D. Waldron. Superintendent of Documents, 1936. Price ten cents. Fuel was injected from different types of injection nozzles into the combustion chamber of the N. A. C. A. combustion apparatus, operated as a compressionignition engine; high-speed motion pictures were taken at the rate of 2,200 frames per second of the fuel sprays and the combustion. Single-orifice nozzles of o-.008-, o.ozo-, and 0.040~inch diameter, and multiorifice nozzles having 2, 6, and 16 Nozzles having impinging jets and slit orifices were also orifices were tested. included. The photographs indicate that the rate of vapor diffusion from the spray is comparatively slow and that this slow rate of diffusion for combustion chambers with little or no air flow prevents the compression-ignition engine, with the present methods of fuel injection, from giving the high performance inherent in the high compression ratios. The sprays from multiorifice nozzles destroyed the air movement to a greater extent than did those from single-orifice nozzles. It is concluded that high performance cannot be realized until the methods of distributing the fuel are improved by means of the injection-nozzle design, air flow, or both. CONSTELLATIOKS. Prepared by the Department of Astronomy of The Franklin Institute. 32 pages, illustrations, 15.5 X 23 ems. Philadelphia, Institute, 1936. Price thirty-five cents. To those who have recently visited the Fels Planetarium in Philadelphia, this booklet is not unfamiliar, but for the information of others who have not visited here it is a revelation of the universe in which we are living. Star maps are shown,