UNT Libraries Government Documents Department - 156 Matching Results

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NACA Investigations of Icing-Protection Systems for Turbojet-Engine Installations

Description: Investigations have been made in flight and in wind tunnels to determine which components of turbojet installations are most critical in icing conditions, and to evaluate several methods of icing protection. From these studies, the requirements necessary for adequate icing protection and the consequent penalties on engine performance can be estimated. Because investigations have indicated that the compressor-inlet screen constitutes the greatest icing hazard and is difficult to protect, complete removal or retraction of the screen upon encountering an icing condition is recommended. In the absence of the screen, the inlet guide vanes of an axial-flow-type turbojet engine constitute the greatest danger to engine operation in an icing condition; a centrifugal-type engine, on the other hand, is relatively unsusceptible to icing once the screen has been removed. Of the three icing-protection systems investigated, surface heating, hot-gas bleedback, and inertia-separation inlets, only the first two offer an acceptable solution to the problem of engine icing protection. Surface heating, either by gas heating or electrical means, appears to be the most acceptable icing-protection method with regard to performance losses. Hot-gas bleedback, although causing undesirable thrust losses, offers an easy means of obtaining icing protection for some installations. The final choice of an icing-protection system depends, however, on the supply of heated gas and electrical power available and on the allowable performance and. weight penalties associated with each system.
Date: May 2, 1951
Creator: VonGlahn, Uwe; Callaghan, Edmund E. & Gray, Vernon H.

Some Research on the Lift and Stability of Wing-Body Combinations

Description: The present paper summarizes and correlates broadly some of the research results applicable to fin-stabilized ammunition. The discussion and correlation are intended to be comprehensive, rather than detailed, in order to show general trends over the Mach number range up to 7.0. Some discussion of wings, bodies, and wing-body interference is presented, and a list of 179 papers containing further information is included. The present paper is intended to serve more as a bibliography and source of reference material than as a direct source of design information.
Date: July 2, 1959
Creator: Purser, Paul E. & Fields, E. M.

Preliminary analysis of problem of determining experimental performance of air-cooled turbine III : methods for determining power and efficiency

Description: Suggested formula are given for determining air-cooled turbine-performance characteristics, such as power and efficiency, as functions of certain parameters. These functions, generally being unknown, are determined from experimental data obtained from specific investigations. Special plotting methods for isolating the effect of each parameter are outlined.
Date: August 2, 1950
Creator: Ellerbrock, Herman H., Jr. & Ziemer, Robert R.

Aerodynamic characteristics with fixed and free transition of a modified delta wing in combination with fuselage at high subsonic speeds

Description: From Introduction: "An investigation of the high-speed aerodynamic characteristics of a modified delta wing in combination with a fuselage was conducted in the Langley high-speed 7- by 10-foot tunnel. The model was tested on the sting support system through a Mach number range of 0.40 to 0.90 with both free and fixed transition. Because of the nature of the transition effect, the results seemed to be of the general interest and are presented in the present paper."
Date: May 2, 1950
Creator: Polhamus, Edward C. & King, Thomas J., Jr.

Experimental investigation of effects of design changes on performance of large-capacity centrifugal compressors

Description: Report presenting an investigation to determine the effects of several design changes on the performance of large-capacity, double-entry, centrifugal compressors. Four modifications of a turbojet engine compressor were operated over a range of equivalent impeller tip speeds an the compressor overall and component performances were determined. Results regarding the impeller performance, diffuser performance, and compressor performance are provided.
Date: March 2, 1951
Creator: Withee, Joseph R., Jr.; Kovach, Karl & Ginsburg, Ambrose

Some properties of beryllium oxide and beryllium oxide - columbium ceramals

Description: High-temperature tensile and thermal-shock investigations were conducted on beryllium oxide and beryllium oxide plus columbium metal additions. X-ray diffraction and metallographic results are given. The tensile strength of 6150 pounds per square inch for beryllium oxide at 1800 degrees F compared favorably with the zirconia bodies previously tested. Additions of 2, 5, 8, 10, 12, and 15 percent by weight of columbium metal failed to improve the shock resistance over that of pure beryllium oxide.
Date: March 2, 1951
Creator: Robards, C. F. & Gangler, J. J.

Lift, drag, and pitching moment of low-aspect-ratio wings at subsonic and supersonic speeds: Plane triangular wing of aspect ratio 4 with NACA 0005-63 section

Description: Report presenting an investigation of a wing-body combination with a plane triangular wing of aspect ratio 4 and NACA 0005-63 sections in streamwise planes at subsonic and supersonic Mach numbers. Lift, drag, and pitching moment are presented for a range of Mach and Reynolds numbers.
Date: February 2, 1951
Creator: Heitmeyer, John C. & Stephenson, Jack D.

Lift, drag, and pitching moment of low-aspect-ratio wings at subsonic and supersonic speeds: Plane triangular wing of aspect ratio 2 with NACA 0003-63 section

Description: Report presenting testing of a wing-body combination with a plane triangular wing of aspect ratio 2 and NACA 0003-63 sections in streamwise planes at subsonic and supersonic Mach numbers. Lift, drag, and pitching moment are presented for a range of Mach and Reynolds numbers.
Date: February 2, 1951
Creator: Heitmeyer, John C. & Smith, Willard G.

Effects of boundary-layer control on the longitudinal characteristics of a 45 degrees swept-forward wing-fuselage combination

Description: Report presenting an investigation to determine the benefits obtainable by applying boundary-layer control to a 45 degree swept-forward wing-fuselage combination. Force and pressure-distribution data were obtained with and without boundary-layer control with various combinations of leading-edge and trailing-edge flaps.
Date: February 2, 1950
Creator: McCormack, Gerald M. & Cook, Woodrow L.

Flight investigation of the effect of thickening the aileron trailing edge on control effectiveness for sweptback tapered wings having sharp-and round-nose sections

Description: Report discussing an investigation of the rolling effectiveness at transonic and supersonic speeds on a 38.1 degree sweptback tapered wing with NACA 0010-64 airfoil sections and partial-span ailerons of true contour with a modified flt-side blunt trailing-edge shape. The variation of Reynolds number with Mach number and the control effectiveness is provided.
Date: May 2, 1950
Creator: Strass, H. Kurt & Fields, Edison M.

Investigation at supersonic speeds of some of the factors affecting the flow over a rectangular wing with symmetrical circular-arc section and 30-percent-chord trailing-edge flap

Description: Report presenting an investigation at supersonic speeds of some of the factors affecting the flow over a rectangular wing with a symmetrical circular-arc section and a 30-percent-chord trailing-edge flap. The main purpose is to obtain more information on which to base the design of supersonic controls. Results regarding the effect of Mach number, effect of wing thickness, effect of fixing transition, effect of sealing the hinge gap, effect of model surface condition and asymmetry, and shock boundary-layer interaction are provided.
Date: January 2, 1951
Creator: Czarnecki, K. R. & Mueller, James N.

Wing-tunnel investigation at Mach numbers from 0.50 to 1.29 of an all-movable triangular wing of aspect ratio 4 alone and with a body

Description: Report presenting the aerodynamic characteristics of an all-movable, triangular-plan-form wing alone and with a body as determined from semispan model tests. The agreement between calculated and experimental results was not satisfactory for the most part, which seemed to be due to the failure of linear theory to define the actual flow field about the configurations investigated. Results regarding lift characteristics, drag characteristics, and pitching-moment characteristics are provided.
Date: February 2, 1950
Creator: Stivers, Louis S. & Malick, Alexander W.

An investigation of convergent-divergent diffusers at Mach number 1.85

Description: Report presenting an investigation in the supersonic tunnel at Mach number 1.85 and angles of attack from 0 to 5 degrees to determine optimum design configurations for a convergent-divergent type of supersonic diffusers with a subsonic diffuser of 5 degrees included divergence angle. Total-pressure recoveries in excess of the theoretical recovery across a normal shock at a free-stream Mach number of 1.85 were obtained with a number of configurations.
Date: February 2, 1951
Creator: Wyatt, DeMarquis D. & Hunczak, Henry R.