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Adaptation of a Cascade Impactor to Flight Measurement of Droplet Size in Clouds

Description: A cascade impactor, an instrument for obtaining: the size distribution of droplets borne in a low-velocity air stream, was adapted for flight cloud droplet-size studies. The air containing the droplets was slowed down from flight speed by a diffuser to the inlet-air velocity of the impactor. The droplets that enter the impactor impinge on four slides coated with magnesium oxide. Each slide catches a different size range. The relation between the size of droplet impressions and the droplet size was evaluated so that the droplet-size distributions may be found from these slides. The magnesium oxide coating provides a permanent record. of the droplet impression that is not affected by droplet evaporation after the. droplets have impinged.
Date: September 18, 1951
Creator: Levine, Joseph & Kleinknecht, Kenneth S.
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics at transonic speeds of a 69 degree delta wing with a triangular plan-form control having a skewed hinge axis and an overhang balance : transonic-bump method

Description: From Introduction: "Presented in this paper are the results of an investigation of a semispan model of a delta wing with 60^o sweepback at the leading edge which was equipped with a large triangular control having an overhang balance mounted on a skewed hinge axis. The purpose of this investigation was to determine the aerodynamic characteristics of a delta wing with a control which was designed to provide aerodynamic balance at zero control deflection based on the span load distribution of reference 1."
Date: February 6, 1951
Creator: Wiley, Harleth G
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics including pressure distribution of a fuselage and three combinations of the fuselage with swept-back wings at high subsonic speeds

Description: From Introduction: "The wings were tested in combination with fuselage similar to the one used in the 7- by 10-foot wind-tunnel investigations. The results are reported herein and are compared with results for three similar model wings on the transonic bump (references 1, 2, and 3)."
Date: February 6, 1951
Creator: Sutton, Fred B & Martin, Andrew
Partner: UNT Libraries Government Documents Department

Aerodynamic Characteristics of a Flying-Boat Hull Having a Length-Beam Ratio of 15, TED No. NACA 2206

Description: An investigation was made in the Langley 300 MPH 7- by 10-foot tunnel to determine the aerodynamic characteristics of a flying-boat hull of a length-beam ratio of 15 in the presence of a wing. The investigation was an extension of previous tests made on hulls of length-beam ratios of 6, 9, and 12; these hulls were designed to have approximately the same hydrodynamic performance with respect to spray and resistance characteristics. Comparison with the previous investigation at lower length-beam ratios indicated a reduction in minimum drag coefficients of 0.0006 (10 peroent)with fixed transition when the length-beam ratio was extended from 12 to 15. As with the hulls of lower length-beam ratio, the drag reduction with a length-beam ratio of 15 occurred throughout the range of angle of attack tested and the angle of attack for minimum drag was in the range from 2deg to 3deg. Increasing the length-beam ratio from 12 to 15 reduced the hull longitudinal instability by an mount corresponding to an aerodynamic-center shift of about 1/2 percent of the mean aerodynamic chord of the hypothetical flying boat. At an angle of attack of 2deg, the value of the variation of yawing-moment coefficient with angle of yaw for a length-beam ratio of 15 was 0.00144, which was 0.00007 larger than the value for a length-beam ratio of 12.
Date: January 23, 1951
Creator: Riebe, John M. & Naeseth, Rodger L.
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics of a slender cone-cylinder body of revolution at a Mach number of 3.85

Description: An experimental investigation of the aerodynamics of a slender cone-cylinder body of revolution was conducted at a Mach number of 3.85 for angles of attack of 0 degree to 10 degrees and a Reynolds number of 3.85x10(exp 6). Boundary-layer measurements at zero angle of attack are compared with the compressible-flow formulations for predicting laminar boundary-layer characteristics. Comparison of experimental pressure and force values with theoretical values showed relatively good agreement for small angles of attack. The measured mean skin-friction coefficients agreed well with theoretical values obtained for laminar flow over cones.
Date: November 5, 1951
Creator: Jack, John R
Partner: UNT Libraries Government Documents Department

Aerodynamic Characteristics of Bodies at Supersonic Speeds: A Collection of Three Papers

Description: The three papers collected here are: 'The Effect of Nose Shape on the Drag of Bodies of Revolution at Zero Angle of Attack.', 'Base Pressure on Wings and Bodies with Turbulent Boundary Layers', and 'Flow over Inclined Bodies'. The subject of the first paper is the drag of the nose section of bodies of revolution at zero angle of attack. The main object of the second paper is to summarize the prinicpal results of the many wind tunnel and free flight measurements of base pressure on both bodies of revolution and blunt trailing edge airfoils.
Date: November 9, 1951
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics of four bodies of revolution showing some effects of afterbody shape and fineness ratio at free-stream Mach numbers from 1.50 to 1.99

Description: The effects of fineness ratio (14.2 and 12.2) and boattailing on aerodynamic characteristics of four bodies of revolution at Mach numbers from 1.50 to 1.99 within a range of angles of attack from 0 degrees 10 degrees at an approximate Reynolds number of 35x10(superscript)6 based on body length were investigated. A comparison of experimental data with available theory is included. At zero angle of attack, fineness ratio has no appreciable effect on model characteristics while boattailing and boattail convergence significantly affect fore drag and base drag. At angle of attack the effects are singular. The theory presented by H. J. Allen is a significant improvement over linearized potential theory in predicting aerodynamic characteristics.
Date: May 22, 1951
Creator: Cohen, Robert J
Partner: UNT Libraries Government Documents Department

Aerodynamics of slender bodies at Mach number of 3.12 and Reynolds numbers from 2 x 10(exp 6) to 15 x 10(exp 6) : body of revolution with near-parabolic forebody and cylindrical afterbody

Description: An experimental investigation of the aerodynamic characteristics of a slender, square-based body of revolution was conducted at a Mach number of 3.12 for angles of attack from 0 degree to 10 degrees and for Reynolds numbers from 2 x 10(exp 6) to 15 x 10(exp 6). Boundary-layer measurements at zero angle of attack are compared with several compressible flow formulating for predicting boundary-layer characteristics. Comparison of experimental pressure and force values with theoretical values showed good agreement for low angles of attack. The measured mean skin-friction coefficients agreed well with those predicted by Mangler's transformation for laminar flow over cones.
Date: November 13, 1951
Creator: Jack, John R & Burgess, Warren C
Partner: UNT Libraries Government Documents Department

Altitude-ignition limit of a turbojet engine using a condenser-discharge ignition system / John C. Armstrong

Description: The altitude-ignition limits of a condenser-discharge ignition system installed on a turbojet engine were determined at a flight Mach number of 0.6 using 1.1-pound Reid vapor pressure fuel. Ignition was possible up to an altitude of 55,000 feet with 4.8 joules per spark and 6 sparks per second.
Date: October 23, 1951
Creator: Armstrong, John C
Partner: UNT Libraries Government Documents Department

Altitude-performance and Reynolds number investigation of centrifugal-flow-compressor turbojet engine

Description: From Introduction: "Altitude-chamber and wind-tunnel investigations of the performance of turbojet engines such as those reported in references 1 to 4 have shown that the conventional correction factors fail to generalize the engine performance variables at high altitudes. An investigation was therefore made at the NACA Lewis laboratory to determine the altitude performance of the J33-A-23 turbojet engine and to demonstrate the magnitude of departure of actual altitude performance from that predicted from sea-level performance."
Date: May 15, 1951
Creator: Wilsted, H D & Grey, R E
Partner: UNT Libraries Government Documents Department

Altitude Performance of J35-A-17 Turbojet Engine in an Altitude Chamber

Description: An investigation of the altitude performance characteristics of an Allison J35-A-17 turbojet engines have been conducted in an altitude chamber at the NACA Lewis laboratory. Engine performance was obtained over a range of altitudes from 20,000 to 60,000 feet at a flight Mach number of 0.62 and a range of flight Mach numbers from 0.42 to 1.22 at an altitude of 30,000 feet. The performance of the engine over the range investigated could be generalized up to an altitude of 30,000 feet. Performance of the engine at any flight Mach number in the range investigated can be predicted for those operating condition a t which critical flow exits in the exhaust nozzle with the exception of the variables corrected net thrust, and net-thrust specific fuel consumption.
Date: January 3, 1951
Creator: Vincent, K. R. & Gale, B. M.
Partner: UNT Libraries Government Documents Department