UNT Libraries Government Documents Department - 41 Matching Results

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Temperatures in Spark Plugs Having Steel and Brass Shells

Description: From Resume: "Brass has often been assumed superior to steel for spark plug shells because of its greater heat conductivity. The measurements described in this report prove the contrary, showing that the interior of a spark plug having a brass shell is from 50 degrees to 150 degrees c. (90 degrees to 270 degrees f.) hotter than that of a similar steel plug. It is to be concluded that steel is to be preferred to brass for spark plug shells. This report embodies the results of measurements taken of electrodes and a comparison of brass and steel insulators of spark plugs while they were in actual operation."
Date: 1919
Creator: Cragoe, C. S.

The general theory of blade screws including propellers, fans, helicopter screws, helicoidal pumps, turbo-motors, and different kinds of helicoidal blades

Description: Report presents a theory which gives a complete picture and an exact quantitative analysis of the whole phenomenon of the working of blade screws, but also unites in a continuous whole the entire scale of states of work conceivable for a blade screw. Chapter 1 is devoted to the establishment of the system of fundamental equations relating to the blade screw. Chapter 2 contains the general discussion of the 16 states of work which may establish themselves for a blade screw. The existence of the vortex ring state and the whirling phenomenon are established. All the fundamental functions which enter the blade-screw theory are submitted to a general analytical discussion. The general outline of the curve of the specific function is examined. Two limited cases of the work of the screw, the screw with a zero constructive pitch and the screw with an infinite constructive pitch, are pointed out. Chapter 3 is devoted to the study of the propulsive screw or propeller. (author).
Date: 1919
Creator: De Bothezat, George

Effect of Compression Ratio, Pressure, Temperature, and Humidity on Power

Description: Among other factors which affect the horsepower of an airplane engine are the atmospheric pressure, and consequently the altitude at which the engine is working, and the compression ratio, or cylinder volume divided by clearance volume. The tests upon which this report is based were selected from a large number of runs made during the intercomparison of various gasolines to determine the variation of horsepower with altitude at three different compression ratios. The test results and conclusions are presented in this report.
Date: 1919
Creator: Dickinson, H. C.; James, W. S.; Anderson, G. V. & Brinkerhoff, V. W.

Experimental research on air propellers

Description: The purposes of the experimental investigation on the performance of air propellers described in this report are as follows: (1) the development of a series of design factors and coefficients drawn from model forms distributed with some regularity over the field of air-propeller design and intended to furnish a basis of check with similar work done in other aerodynamic laboratories, and as a point of departure for the further study of special or individual types and forms; (2) the establishment of a series of experimental values derived from models and intended for later use as a basis for comparison with similar results drawn from certain selected full-sized forms and tested in free flight.
Date: 1918
Creator: Durand, William F.

Experimental research on air propellers, 2

Description: This report is a continuation of NACA Technical Report 14. It presents the results of an experimental investigation on the performance of air propellers which was divided into five parts, as follows: (1) Tests under conditions of flight on 16 model propellers of different forms, sections, or pitch ratios from those of Technical Report 14; (2) Tests under conditions of flight on one model propeller of variable pitch; (3) Tests under conditions of flight on three sets of right and left hand model propellers in series; (4) Tests on 12 model propellers to determine brake effect or negative thrust at negative slip; (5) Standing thrust and power tests of 67 model propellers.
Date: 1919
Creator: Durand, William F. & Lesley, E. P.

Investigation of Pitot tubes

Description: Report describes the principles of operation and characteristics of some of the instruments which have been devised or used to measure both low and high speeds of aeroplanes. Since the pitot tube is the instrument which has been most commonly used in the United States and Great Britain as a speedometer for aeroplanes, it is treated first and somewhat more fully than the others.
Date: 1917
Creator: Herschel, W H & Buckingham, E

Report on behavior of aeroplanes in gusts

Description: Part 1 presents the results of a wind tunnel test of a biplane model with an 18 inch span. The lift, drift, and pitching moment were measured for a series of angles of incidence corresponding to the maximum possible changes of flight attitude. Only the discussion of symmetrical or longitudinal changes is given. From the observed rate of variation of the forces and pitching moment, it was possible to calculate the derivatives needed in the complete theory of longitudinal stability in still air. The damping of the pitching oscillation was also determined experimentally. Part 2 presents a theoretical method for determining the effects of gusts on aeroplanes in the following cases: (1) head-on gusts rising from 0 to j feet per second with various degrees of sharpness, (2) up gusts of the same type, (3) rotary gusts of the same type, (4) rear gusts and down gusts are included by merely changing the sign of j.
Date: October 7, 1915
Creator: Hunsaker, Jerome C. & Wilson, Edward Bidwell

An investigation of the elements which contribute to statical and dynamical stability, and of the effects of variation in those elements

Description: Part 1 gives details of models tested and methods of testing of the Eiffel 36 wing alone and the JN2 aircraft. Characteristics and performance curves for standard JN are included. Part 2 presents a statistical analysis of the following: lift and drag contributed by body and chassis tested without wings; lift and drag contributed by tail, tested without wings; the effect on lift and drift of interference between the wings of a biplane combination; lift and drag contributed by the addition of body, chassis, and tail to a biplane combination; total parasite resistance; effect of varying size of tail, keeping angle of setting constant; effect of varying length of body and size of tail at the same time, keeping constant moment of tail surface about the center of gravity; forces on the tail and the effects of downwash; effect of size and setting of tail on statical longitudinal stability effects of length of body on stability; the effects of the various elements of an airplane on longitudinal stability and the placing of the force vectors. Part 3 presents the fundamental principals of dynamical stability; computations of resistance derivatives; solution of the stability equation; dynamical stability of the Curtiss JN2; tabulation of resistance derivatives; discussion of the resistance derivatives; formation and solution of stability equations; physical conceptions of the resistance derivatives; elements contributing to damping and an investigation of low speed conditions. Part 4 includes a summary of the results of the statistical investigation and a summary of the results for dynamic stability.
Date: 1918
Creator: Klemin, Alexander; Warner, Edward P. & Denkinger, George M.

The airplane tensiometer

Description: Certain parts of an airplane are subjected not only to the stresses imposed by the aerodynamic or flying load, but also to the initial stresses, caused by the tension in the stay and drift wires. Report describes a tensiometer that measures such stresses which is simple in construction, accurate, and easily and quickly operated even by inexperienced persons. Two sizes of the instrument are available. One is suitable for wires up to one-fourth inch in diameter and the other for wires from one-fourth to three-eights inch in diameter.
Date: 1919
Creator: Larson, L. J.

Air flow through poppet valves

Description: Report discusses the comparative continuous flow characteristics of single and double poppet valves. The experimental data presented affords a direct comparison of valves, single and in pairs of different sizes, tested in a cylinder designed in accordance with current practice in aviation engines.
Date: 1918
Creator: Lewis, G W & Nutting, E M

Thermodynamic Efficiency of Present Types of Internal Combustion Engines for Aircraft

Description: Report presents requirements of internal combustion engines suitable for aircraft. Topics include: (1) service requirements for aeronautic engines - power versus weight, reliability, and adaptability factors, (2) general characteristics of present aero engines, (3) aero engine processes and functions of parts versus power-weight ratio, reliability, and adaptability factors, and (4) general arrangement, form, proportions, and materials of aero parts - power-weight ratio, reliability, and adaptability.
Date: 1917
Creator: Lucke, Charles E.