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The Supersonic Axial-Flow Compressor

Description: An investigation has been made to explore the possibilities of axial-flow compressors operating with supersonic velocities into the blade rows. Preliminary calculations showed that very high pressure ratios across a stage, together with somewhat increased mass flows, were apparently possible with compressors which decelerated air through the speed of sound in their blading. The first phase of the investigation was the development of efficient supersonic diffusers to decelerate air through the speed of sound. The present report is largely a general discussion of some of the essential aerodynamics of single-stage supersonic axial-flow compressors. As an approach to the study of supersonic compressors, three possible velocity diagrams are discussed briefly. Because of the encouraging results of this study, an experimental single-stage supersonic compressor has been constructed and tested in Freon-12. In this compressor, air decelerates through the speed of sound in the rotor blading and enters the stators at subsonic speeds. A pressure ratio of about 1.8 at an efficiency of about 80 percent has been obtained.
Date: January 1, 1950
Creator: Kantrowitz, Arthur
Partner: UNT Libraries Government Documents Department

Extension of Useful Operating Range of Axial-Flow Compressors by Use of Adjustable Stator Blades

Description: A theory has been developed for resetting the blade angles of an axial-flow compressor in order to improve the performance at speeds and flows other than the design and thus extend the useful operating range of the compressor. The theory is readily applicable to the resetting of both rotor and stator blades or to the resetting of only the stator blades and is based on adjustment of the blade angles to obtain lift coefficients at which the blades will operate efficiently. Calculations were made for resetting the stator blades of the NACA eight-stage axial-flow compressor for 75 percent of design speed and a series of load coefficients ranging from 0.28 to 0.70 with rotor blades left at the design setting. The NACA compressor was investigated with three different blade settings: (1) the design blade setting, (2) the stator blades reset for 75 percent of design speed and a load coefficient of 0.48, and (3) the stator blades reset for 75 percent of design speed and a load coefficient of 0.65.
Date: January 1, 1948
Creator: Sinnette, John T & Voss, William J
Partner: UNT Libraries Government Documents Department

Paths of Target Seeking Missiles in Two Dimensions

Description: Parameters that enter into equation of trajectory of a missile are discussed. Investigation is made of normal pursuit, of constant, proportional, and line--of-sight methods of navigation employing target seeker, and of deriving corresponding pursuit paths. Pursuit paths obtained under similar conditions for different methods are compared. Proportional navigation is concluded to be best method for using target seeker installed in missile.
Date: July 1, 1946
Creator: Watkins, Charles E.
Partner: UNT Libraries Government Documents Department

Parameters determining performance of supersonic pilotless airplanes powered by ram-compression power planes

Description: Report presenting the dimensional parameters of ram-compression power plants as related to their thrust and economy performance and an investigation of the speed and range performance possibilities of a family of pilotless airplanes powered with one of the power plants. The analysis of the power plants includes the power-plant configuration, aerodynamic and thermodynamic cycle, constants used in the computations, power-plant performance, and operation of the power unit with fixed areas at various flight speeds. The investigation of the aircraft included a description of its characteristics, speed, range, effect of wing selection of speed, and effect of size on performance.
Date: June 1946
Creator: Hill, Paul R.
Partner: UNT Libraries Government Documents Department

Critical Mach Numbers of Thin Airfoil Sections with Plain Flaps

Description: Critical Mach number as function of lift coefficient is determined for certain moderately thick NACA low-drag airfoils. Results, given graphically, included calculations on same airfoil sections with plain flaps for small flap deflections. Curves indicate optimum critical conditions for airfoils with flaps in such form that they can be compared with corresponding results for zero flap deflections. Plain flaps increase life-coefficient range for which critical Mach number is in region of high values characteristic of low-drag airfoils.
Date: April 1, 1946
Creator: Pardee, Otway O'm. & Heaslet, Max A.
Partner: UNT Libraries Government Documents Department

Field of Flow About a Jet and Effect of Jets on Stability of Jet-Propelled Airplanes

Description: A theoretical investigation was conducted on jet-induced flow deviation. Analysis is given of flow inclination induced outside cold and hot jets and jet deflection caused by angle of attack. Applications to computation of effects of jet on longitudinal stability and trim are explained. Effect of jet temperature on flow inclination was found small when thrust coefficient is used as criterion for similitude. The average jet-induced downwash over tail plane was obtained geometrically.
Date: April 1, 1946
Creator: Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department

Development of Wing Inlets

Description: Lift, drag, internal flow, and pressure distribution measurements were made on a low-drag airfoil incorporating various air inlet designs. Two leading-edge air inlets are developed which feature higher lift coefficients and critical Mach than the basic airfoil. Higher lift coefficients and critical speeds are obtained for leading half of these inlet sections but because of high suction pressures near exist, slightly lower critical speeds are obtained for the entire inlet section than the basic airfoil.
Date: March 1, 1946
Creator: Racisz, Stanley F.
Partner: UNT Libraries Government Documents Department

Flight Investigation at High Speeds of Profile Drag of Wing of a P-47D Airplane Having Production Surfaces Covered with Camouflage Paint

Description: Wing section outboard of flap was tested by wake surveys in Mach range of 0.25 - 0.78 and lift coefficient range 0.06 - 0.69. Results indicated that minimum profile-drag coefficient of 0.0097 was attained for lift coefficients from 0.16 to 0.25 at Mach less than 0.67. Below Mach number at which compressibility shock occurred, variations in Mach of 0.2 had negligible effect on profile drag coefficient. Shock was not evident until critical Mach was exceeded by 0.025.
Date: March 1, 1946
Creator: Daum, Fred L. & Zalovcik, John A.
Partner: UNT Libraries Government Documents Department

Effect of Compressibility on the Pressure and Forces Acting on a Modified NACA 65,3-019 Airfoil Having a 0.20-Chord Flap

Description: An investigation has been conducted in the Langley rectangular high-speed tunnel to determine the effect of compressibility on the pressure distribution for a modified NACA 65,3-019 airfoil having a 0.20-chord flap. The investigation was made for an angle-of-attack range extending from -2 to 12 deg at .20 flap deflections from 0 to -12 deg. Test data were obtained for Mach numbers from 0.28 to approximately 0.74. The results show that the effectiveness of the trailing-edge-type control surface rapidly decreased and approached zero as the Mach number increased above the critical value.
Date: January 1, 1946
Creator: Lindsey, W F
Partner: UNT Libraries Government Documents Department