UNT Libraries Government Documents Department - 1,263 Matching Results

Search Results

Performance Charts for a Turbojet System

Description: Convenient charts are presented for computing the thrust, fuel consumption, and other performance values of a turbojet system. These charts take into account the effects of ram pressure, compressor pressure ratio, ratio of combustion-chamber-outlet temperature to atmospheric temperature, compressor efficiency, turbine efficiency, combustion efficiency, discharge-nozzle coefficient, losses in total pressure in the inlet to the jet-propulsion unit and in the combustion chamber, and variation in specific heats with temperature. The principal performance charts show clearly the effects of the primary variables and correction charts provide the effects of the secondary variables. The performance of illustrative cases of turbojet systems is given. It is shown that maximum thrust per unit mass rate of air flow occurs at a lower compressor pressure ratio than minimum specific fuel consumption. The thrust per unit mass rate of air flow increases as the combustion-chamber discharge temperature increases. For minimum specific fuel consumption, however, an optimum combustion-chamber discharge temperature exists, which in some cases may be less than the limiting temperature imposed by the strength temperature characteristics of present materials.
Date: June 1947
Creator: Pinkel, Benjamin & Karp, Irving M.

An Experimental Investigation of Flow Conditions in the Vicinity of an NACA D(Sub S)-Type Cowling

Description: Data are presented of the flow conditions in the vicinity of an NACA D sub S -type cowling. Tests were made of a 1/2 scale-nacelle model at inlet-velocity ratios ranging from 0.23 to 1.02 and angles of attack from 6 deg to 10 deg. The velocity and direction of flow in the vertical plane of symmetry of the cowling were determined from orifices and tufts installed on a board aligned with the flow. Diagrams showing velocity ratio contours and lines of constant flow angles are given.
Date: August 1946
Creator: Bryant, Rosemary P. & Boswinkle, Robert W., Jr.

Wind-tunnel tests and analysis of three 10-foot-diameter three-blade tractor propellers differing in pitch distribution

Description: Report discussing an investigation of the effect of variations in pitch distribution on propeller efficiency at low Mach numbers. The three 10-foot-diameter propellers tested consisted of three blades mounted on a streamline body and were tested for a blade-angle range from 15 degrees to 60 degrees. Information about the propeller thrust, power coefficients, force-balance measurements, and total pressure in the propeller wake is provided.
Date: August 1946
Creator: Gilman, Jean, Jr.

Aerodynamic characteristics of several modifications of a 0.45-scale model of the vertical tail of the Curtiss XP-62 airplane

Description: From Introduction: "In the course of an investigation to find a satisfactory vertical tail for the XP-62 airplane, a 0.45-scale vertical tail model on a stub fuselage was tested in the Langley 7- by 10-foot tunnel. This model was fitted with a flat plate to represent the horizontal tail surface. The data are presented herein for their general interest value rather than their application to this particular airplane."
Date: July 1946
Creator: Lowry, John G.; Turner, Thomas R. & Liddell, Robert B.

Analysis of V-G Records from the SNB-1 Airplane

Description: Availability data obtained on SNB-1 trainer-class airplanes were analyzed and results presented as flight envelopes which predict occurrences of large values of air speed and acceleration. Comparison is made with SNJ-4 trainer-class airplane data analyzed by the same method. It is concluded that flight envelopes are satisfactory; that the two types show large differences in flight loads and speeds experience; and that SNB-1 will seldom, if ever, exceed design limit load factor and restricted speed, which SNJ-4 can be expected to exceed design-limit load factor and restricted speed in a very small number of flight hours.
Date: July 1946
Creator: Walker, Walter G. & Meadows, May T.

The effect of increase in combustion-air inlet temperature from 80 to 130 F on the sea-level performance of a 22-inch-diameter pulse-jet engine

Description: Report discussing testing on 22 inch-diameter pulse-jet engines to determine the effect on performance of a change in combustion-air temperature from approximately 80 degrees to 130 degrees. The effects on jet thrust, combustion-air flow, and engine thrust are described.
Date: July 1946
Creator: Valerino, Michael F.; Essig, Robert H. & Hughes, Richard F.

Efficiency of a radial-flow exhaust-gas turbosupercharger turbine with a 12.75-inch tip diameter

Description: Report discussing the effects of various inlet pressures, inlet temperatures, wheel speeds, pressure ratios, and cooling-air flows on the performance of a radial-flow exhaust-gas turbosupercharger turbine with a 12.75-inch tip diameter. Information about efficiency is provided for a given blade-to-jet speed ratio.
Date: July 1946
Creator: Coulter, Earl E.; Larkin, Robert G. & Gabriel, David S.

Flight investigation of factors affecting the carburetor ram and nacelle drag of an A-26B airplane

Description: From Summary: "Flight tests of an A-26B airplane have been conducted to determine the changes in maximum speed, as affected by changes in carburetor ram and aerodynamic refinement of the nacelles, resulting from the addition of sealed spinners and modification of the charge air system, cowling, and nacelle afterbodies. The changes in nacelle drag resulting from these modifications were measured independently by means of a revolving wake survey rake behind the nacelle and boundary layer rakes on the cowling, and provide a quantitative check of the speed measurements as well as a means of analyzing the components of nacelle drag."
Date: July 1946
Creator: Johnston, J. Ford; Klawans, Bernard B. & Danforth, Edward C. B., III

Flight Investigation to Improve the Dynamic Longitudinal Stability and Control-Feel Characteristics of the P-63A-1 Airplane (AAF No. 42-68889) with Closely Balanced Experimental Elevators

Description: Results of flight tests of a control-feel aid presented. This device consisted of a spring and dashpot connected in series between the control stick and airplane structure. The device was tested in combination with an experimental elevator and bobweight which had given unsatisfactory dynamic stability and control-feel characteristics in previous tests. The control-feel aid effected marked improvement in both the control-feel characteristics and the control-feel dynamic longitudinal stability of the airplane.
Date: July 1946
Creator: Johnson, Harold I.

A preliminary theoretical study of helicopter-blade flutter involving dependence upon coning angle and pitch setting

Description: From Summary: "A preliminary analysis has been made of the conditions of stability of free oscillations of a hinged rotor in hovering flight. The case analyzed is a rotor with hinges allowing freedom in flapping and lagging and having a completely reversible cyclic pitch-control system, so that a twisting moment on a blade moves the control stick without hindrance from spring or friction constraint. The principal results of this study are presented in the form of a stability chart."
Date: July 1946
Creator: Coleman, Robert P

Aerodynamics of the carburetor air scoop and the engine cowling of a single-engine torpedo-bomber-type airplane

Description: From Introduction: "An investigation of the power-plant installation of a single-engine torpedo-bomber-type airplane has been conducted in the NACA Cleveland altitude wind tunnel at the request of the Bureau of Aeronautics, Navy Department. A similar investigation was previously conducted on a three-tenths scale mock-up of the forward portion of the fuselage of this airplane in the Langley 20-foot tunnel. (See reference 1)."
Date: June 1946
Creator: Palter, Herman

Effect of a low-loss air valve on performance of a 22-inch-diameter pulse-jet engine

Description: Report presenting the performance of a 22-inch-diameter pulse-jet engine using a net of low-loss modified air valves at ram pressures equivalent to simulated flight speeds. Results regarding combustion-air weight flow, flight thrust, maximum combustion-chamber pressure, specific fuel consumption, pressure cycle, and valve life are provided.
Date: June 1946
Creator: Bressman, Joseph R.

Flight measurements by various methods of the drag characteristics of the XP-51 airplane

Description: Report discussing measurements of the overall drag coefficient of the XP-51 in dives using three different methods. The three instruments used to measure drag variation are compared for accuracy. A comparison of the drag results obtained from this test are also compared to the results obtained from previous wind tunnel testing.
Date: June 1946
Creator: Pearson, Henry A. & Beadle, Dorothy E.

Investigation of ice formation in the induction system of an aircraft engine 2: flight tests

Description: From Summary: "Flight tests were conducted on a twin-engine fighter airplane at pressure altitudes up to 10,000 feet with simulated conditions of moderate, heavy, and excessive rain to determine the increase in enthalpy of the charge air due to the turbosupercharger, to determine the rate of enthalpy increase of the charge air resulting from a sudden increase of engine power, and to compare the conditions that caused induction-system icing in flight with those that resulted in icing of the same carburetor and supercharger inlet elbow in laboratory tests."
Date: June 1946
Creator: Essex, Henry A.; Ellisman, Carl & Zlotowski, Edward D.