National Advisory Committee for Aeronautics (NACA) - 40 Matching Results

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Flight tests of the high-speed performance of a P-51B airplane (AAF no. 43-12105)

Description: Report discussing testing to check the improvement of 3 or 4 miles per hour in the maximum speed of the P-51B airplane as a result of sealing the wing-gun access doors and flap-spar lightening holes. Large variations in speed were observed during testing, so additional testing and analysis was carried out to determine the effects of various factors that were suspected of contributing to the inconsistency of the plane's performance.
Date: December 18, 1944
Creator: Voglewede, T. J. & Danforth, E. C. B.
Partner: UNT Libraries Government Documents Department

A preliminary theoretical study of aerodynamic instability of a two-blade helicopter rotor

Description: Report presenting numerical results of flutter calculations for a two-blade helicopter using a see-saw-type rotor. The stability condition for oscillatory motion is expressed in terms of a small number of composite parameters that are evaluated from moments of inertia, angle settings, and aerodynamic parameters of a blade. The analysis indicated that a see-saw rotor with a coning angle is more unstable than an airplane wing with the same parameters.
Date: March 18, 1947
Creator: Coleman, Robert P. & Stempin, Carl W.
Partner: UNT Libraries Government Documents Department

Theoretical investigation of the dynamic lateral stability characteristics of Douglas design No. 39C, an early version of the X-3 research airplane

Description: Contains results of calculations made to determine the neutral oscillatory stability boundaries, period and time to damp of the oscillatory mode, and motions following disturbances. The calculations were made for Mach numbers of 0.75 and 2.3 at an attitude of 35,000 feet and for the landing condition at sea level.
Date: January 18, 1949
Creator: Bennett, Charles V.
Partner: UNT Libraries Government Documents Department

An analysis of a piston-type gas-generator engine

Description: From Introduction: "An analysis of an engine having a division of work such that the power of the reciprocating engine is just sufficient to drive the compressor is reported herein. This combination of a reciprocating-type internal-combustion engine that drives its own supercharging compressor and generates gas for further expansion through a turbine will be called a piston-type gas generator in this report."
Date: February 18, 1948
Creator: Tauschek, Max J & Biermann, Arnold E
Partner: UNT Libraries Government Documents Department

Preliminary measurements of the dynamic lateral stability characteristics of the Douglas D-588-II (BuAero No. 37974) airplane

Description: From Summary: "This paper presents some data on the dynamic lateral stability characteristics of the Douglas D-558-II (BuAero No. 37974) airplane. For the airplane in the clean condition, the lateral oscillations are lightly damped. In the landing condition, the airplane performs a constant-amplitude lateral oscillation."
Date: August 18, 1949
Creator: Sjoberg, Sigurd A.
Partner: UNT Libraries Government Documents Department

Effect of engine-operating variables and internal coolants on spark-advance requirements of a liquid-cooled cylinder

Description: From Summary: "Tests were conducted to determine the effect of engine-operating variables and internal coolants on spark-advance requirements of a single cylinder from a 12-cylinder liquid-cooled engine for maximum take-off power and maximum cruise economy. The effects of fuel-air ratio, engine speed, air flow (charge density), mixture temperature, and internal coolants on peak-power (optimum) spark advance were investigated. In addition, tests were conducted to determine the effect of spark advance on the knock-limited engine performance at several mixture temperatures for conditions simulating take-off, high-power cruise, and low-power cruise."
Date: May 18, 1945
Creator: Pfender, John F.; Dudugjian, Carl & Lietzke, A. F.
Partner: UNT Libraries Government Documents Department

A Time History of Control Operation of a C-54 Airplane in Blind Landing Approaches

Description: Tests were made with a C-54 airplane in which airline pilots made several blind approaches to determine whether any special flying techniques were used in blind landings and whether any special handling-qualities requirements would have to be formulated because of such special techniques. It was found that the airplane was flown at all times in the normal manner; that is, all turns were banked turns that were nearly coordinated by use of the rudder so that the sideslip was held close to zero. The pilot expended considerable physical work in continually moving the controls but this wake was due in part to the large friction in the three control systems. The actual control deflections used were small compared to the maximum deflections available.
Date: July 18, 1947
Creator: Talmage, Donald B.
Partner: UNT Libraries Government Documents Department

An Investigation of the Aerodynamic Characteristics of an 0.08-Scale Model of the Chance Vought XF7U-1 Airplane in the Langley High-Speed 7- by 10-Foot Tunnel. Part II - Basic Lateral Stability Characteristics TED No. NACA DE308, Part 2, Basic Lateral Stability Charactistics, TED No. NACA DE308

Description: Tests have been conducted in the Langley high-speed 7- by 10-foot tunnel over a Mach number range from 0.40 to 0.91 to determine the stability and control characteristics of an 0.08-scale model of the Chance Vought XF7U-1 airplane. The basic lateral stability characteristics of the complete model with undeflected control surfaces are presented in the present report with a very limited analysis of the results.
Date: July 18, 1947
Creator: Kemp, William B., Jr.; Goodson, Kenneth W. & Kuhn, Richard E.
Partner: UNT Libraries Government Documents Department

Free-Spinning-Tunnel Tests of a 1/35-Scale Model of the Douglas XB-43 Airplane

Description: Spin tests have been performed in the Langley 20-foot free-spinning tunnel on a 1/35-scale model of the Douglas XB-43 airplane. The spin and recovery characteristics were determined for several loading conditions of the airplane. The effects of installing a dorsal fin and of installing a ventral fin were investigated. Emergency escape of the crew was simulated and the stick and rudder pedal forces necessary to effect recoveries on the airplane were determined.
Date: July 18, 1947
Creator: Snyder, Thomas L.
Partner: UNT Libraries Government Documents Department

Effects of Wing Flaps and Wing Duct Inlet on the Lift and Stalling Characteristics of a 1/4-Scale Partial-Span Model of the Republic XF-12 Airplane in the Langley 19-Foot Pressure Tunnel

Description: An investigation was conducted in the Langley 19-foot pressure tunnel to determine the lift, drag, pitching-moment and stalling characteristics fo a 1/4 -scale partial-span model of the left wing of the Republic XF-12 airplane. The effects of a duct inlet, located between the nacelles at the leading edge of the wing, on those characteristics were also investigated. The Reynolds numbers for the investigation covered a range from 4,500,000 to 8,600,000. The results of the investigation indicated that maximum lift coefficients of 1.36, 1.71, and 2.11 were measured on the model with flaps neutral and deflected 20 deg and 55 deg, respectively at a Reynolds number of 8,600,000. When the duct inlet was replaced by a basic airfoil nose the flap-neutral maximum-lift coefficient was increased from 1.36 to 1.41. The results also showed that at maximum lift with flaps neutral or deflected 55 deg. most of the area between the nacelles were stalled while only small areas on other portions of the model were stalled; when the duct inlet was replaced by the basic airfoil nose the stall was delayed to a slightly higher angle of attack but the nature of the stall was relatively unaffected.
Date: November 18, 1946
Creator: Graham, Robert R.; Martina, Albert P. & Salmi, Reino J.
Partner: UNT Libraries Government Documents Department

NACA Conference on Aircraft Loads

Description: This document contains reproductions of technical papers on some of the recent research results from the NACA Laboratories in the field of aircraft loads. These papers were presented at the NACA Conference on Aircraft Loads held at the Langley Memorial Aeronautical Laboratory, February 18 and 19, 1948. The primary purpose of this conference was to convey these research results to the military services and their airplane contractors and to provide those attending an opportunity for discussion of the results. The papers in this document were prepared for presentation at the conference and are considered as complementary to, rather than as substitutes for, the Committee's more complete and formal reports.
Date: 1948-02-18/1948-02-19
Partner: UNT Libraries Government Documents Department

Cooling of Gas Turbines, 2, Effectiveness of Rim Cooling of Blades

Description: An analysis is presented of rim cooling of gas-turbine blades; that is, reducing the temperature at the base of the blade (wheel rim), which cools the blade by conduction alone. Formulas for temperature and stress distributions along the blade are derived and, by the use of experimental stress-rupture data for a typical blade alloy, a relation is established between blade life (time for rupture), operating speed, and amount of rim cooling for several gas temperatures. The effect of blade parameter combining the effects of blade dimensions, blade thermal conductivity, and heat-transfer coefficient is determined. The effect of radiation on the results is approximated. The gas temperatures ranged from 1300F to 1900F and the rim temperature, from 0F to 1000F below the gas temperature. This report is concerned only with blades of uniform cross section, but the conclusions drawn are generally applicable to most modern turbine blades. For a typical rim-cooled blade, gas temperature increases are limited to about 200F for 500F of cooling of the blade base below gas temperature, and additional cooling brings progressively smaller increases. In order to obtain large increases in thermal conductivity or very large decreases in heat-transfer coefficient or blade length or necessary. The increases in gas temperature allowable with rim cooling are particularly small for turbines of large dimensions and high specific mass flows. For a given effective gas temperature, substantial increases in blade life, however, are possible with relatively small amounts of rim cooling.
Date: March 18, 1947
Creator: Wolfenstein, Lincoln; Meyer, Gene L. & McCarthy, John S.
Partner: UNT Libraries Government Documents Department