National Advisory Committee for Aeronautics (NACA) - 742 Matching Results

Search Results

NACA: University Conference on Aerodynamics, A Compilation of the Papers Presented

Description: This document contains reproductions of the technical papers presented at the NACA - University Conference on Aerodynamics held at the Langley Aeronautical Laboratory on June 21, 22, and 23, 1948. The conference was held in recognition of the difficulties, imposed by security restrictions, in keeping abreast of the rapid advances in aerodynamics. The papers were prepared to review the status of a number of fields of interest, to summarize the more important wartime advances that are no longer classified, and to orient reference material for further study. The papers in this document are in the same form in which they were presented at the conference so that distribution of them might be prompt. The original presentation and this record are considered as complementary to, rather than as substitutes for, the Committee?s system of complete and formal reports.
Date: 1948-06-21/1948-06-23
Partner: UNT Libraries Government Documents Department

Icing and De-Icing of a Propeller with Internal Electric Blade Heaters

Description: An investigation has been made in the NACA Cleveland icing research tunnel to determine the de-icing effectiveness of an experimental configuration of an Internal electric propeller-blade heater. Two atmospheric Icing conditions and two propeller operating conditions were Investigated, In experiments with unheated blades and with heat applied to the blades both continuously and cyclically. Data are presented to show the effect of propeller speed., ambient air temperature and liquid-water concentration, and the duration of the heat-on and cycle times on the power requirements and de-Icing performance of the blade heaters. The extent of ice-covered area on the blades for various icing ax4 operating conditions has been determined. The largest iced area was obtained at the higher ambient-air temperatures and at low propeller speed. The ohord.wise extent of Icing In practically every case was greater than that covered by blade heaters. Adequate de-icing in the heated area with continuous application of heat was obtained with the power available but a maximum power, input of 1250 watts per blade was insufficient for cyclic de-Icing for the range of conditions investigated. Blade-surface temperature rates of rise of 0.2 to 0.7 F per second were obtained and the minimum cooling period for cyclic de-icing was found to be approximately 2-1/2 times the heating period.
Date: August 1948
Creator: Lewis, James P. & Stevens, Howard C., Jr.
Partner: UNT Libraries Government Documents Department

Determination of Stresses in Gas-turbine Disks Subjected to Plastic Flow and Creep

Description: From Summary: "A finite-difference method previously presented for computing elastic stresses in rotating disks is extended to include the computation of the disk stresses when plastic flow and creep are considered. A finite-difference method is employed to eliminate numerical integration and to permit nontechnical personnel to make the calculations with a minimum of engineering supervision. Illustrative examples are included to facilitated explanation of the procedure by carrying out the computations on a typical gas-turbine disk through a complete running cycle."
Date: 1948
Creator: Millenson, M. B. & Manson, S. S.
Partner: UNT Libraries Government Documents Department

Effects of Ice Formations on Airplane Performance in Level Cruising Flight

Description: A flight investigation in natural icing conditions was conducted by the NACA to determine the effect of ice accretion on airplane performance. The maximum loss in propeller efficiency encountered due to ice formation on the propeller blades was 19 percent. During 87 percent of the propeller icing encounters, losses of 10 percent or less were observed. Ice formations on all of the components of the airplane except the propellers during one icing encounter resulted in an increase in parasite drag of the airplane of 81 percent. The control response of the airplane in this condition was marginal.
Date: May 1948
Creator: Preston, G. Merritt & Blackman, Calvin C.
Partner: UNT Libraries Government Documents Department

Investigation of Effectiveness of Air-Heating a Hollow Steel Propeller for Protection Against Icing 1: Unpartitioned Blades

Description: From Summary: "An investigation to determine the effectiveness of icing protection afforded by air-heating hollow steel unpartitioned propeller blades has been conducted In the NACA Cleveland icing research tunnel. The propeller used was a production model modified with blade shank and tip openings to permit internal passage of heated air. Blade-surface and heated-air temperatures were obtained and photographic observations of Ice formations were made with variations In icing intensity and heating rate to the blades. For the conditions of Icing to which the propeller was subjected, it was found that adequate ice protection was afforded with a heating rate of 40 1 000 Btu per hour per blade."
Date: May 1948
Creator: Mulholland, Donald R. & Perkins, Porter J.
Partner: UNT Libraries Government Documents Department

Investigation of Effectiveness of Air-Heating a Hollow Steel Propeller for Protection Against Icing. 2: 50% Impartitioned Blades

Description: From Summary: "The icing protection afforded an internal air-heated propeller blade by radial partitioning at 50-percent chord to confine the heated air to the forward half of the blade was determined in the NACA Cleveland icing research tunnel. A modified production-model hollow steel propeller, was used for the investigation. Temperatures of the blade surfaces for several heating rates were measured under various tunnel icing conditions. Photographic observations of ice formations on blade surfaces and blade heat-exchanger effectiveness were obtained."
Date: May 1948
Creator: Perkins, Porter J. & Mulholland, Donald R.
Partner: UNT Libraries Government Documents Department

Investigation of Effectiveness of Air-Heating a Hollow Steel Propeller for Protection Against Icing. 3: 25% Partitioned Blades

Description: From Summary: "The icing protection obtained from an internally air-heated propeller blade partitioned to confine the heated air forward of 25-percent chord was investigated in the NACA Cleveland icing research tunnel. A production-model hollow steel propeller was modified with an Internal radial partition at 25-percent chord and with shank and tip openings to admit and exhaust the heated air. Temperatures were measured on the blade surfaces and in the heated-air system during tunnel icing conditions. Heat-exchanger effectiveness and photographs of Ice formations on the blades were obtained."
Date: May 1948
Creator: Mulholland, Donald R. & Perkins, Porter J.
Partner: UNT Libraries Government Documents Department

Hydrodynamic Characteristics of a Low-Drag, Planing-Tail Flying-Boat Hull

Description: Report discussing the hydrodynamic characteristics of a flying boat with a low-drag, planing-tail hull compared with a conventional-type hull. The planing-tail model had more take-off stability than the conventional model and had lower hydrodynamic resistance. Information about the landing stability, variation of trim with speed, and spray characteristics is also provided.
Date: October 21, 1948
Creator: Suydam, Henry B.
Partner: UNT Libraries Government Documents Department

Additional abstracts pertaining to seaplanes

Description: From Summary: "About 500 additional references pertaining to hydrodynamic design of seaplanes have been compiled, and the information is presented in the form of abstracts classified under six main headings:GENERAL INFORMATION, HYDROSTATICS, HYDRODYNAMICS, AERODYNAMICS, OPERATION, and RESEARCH. The compilation is an extension of NACA RM No. L6I13, entitled "Abstracts Pertaining to Seaplanes," by Jerold M. Bidwell and Douglas A. King. An author index and a subject index are included."
Date: March 9, 1948
Creator: Bidwell, J. M. & King, D. A.
Partner: UNT Libraries Government Documents Department

AVA monographs. B: Boundary layer

Description: Report discusses several experiments regarding boundary layers and their influence on aircraft. The first experiment investigates how to best design airfoils. The second involves using suction to remove the boundary layer. The third involves surface disturbances and how they may affect the boundary layer.
Date: April 1, 1948
Creator: Holstein, H.; Bete, A. & Tollmein, W.
Partner: UNT Libraries Government Documents Department

Natural Icing of an Axial-Flow Turbojet Engine in Flight for a Single Icing Condition

Description: Memorandum presenting an investigation in natural icing conditions to determine the effect of ice formations on the performance of an axial-flow turbojet engine. A description of the change over time in tail-pipe temperature, engine jet thrust, fuel flow, ice collection, and acceleration qualities are provided.
Date: August 12, 1948
Creator: Acker, Loren W.
Partner: UNT Libraries Government Documents Department

Stability and control characteristics at low speed of an airplane model having a 38.7 degree sweptback wing with aspect ratio 4.51, taper ratio 0.54, and conventional tail surfaces

Description: Report presenting a low-speed wind-tunnel investigation of a scale model of an airplane with a 38.7 degree sweptback wing with an aspect ratio of 4.51, a taper ratio of 0.54, and conventional tail surfaces. Results regarding the lift characteristics, longitudinal stability, longitudinal control, directional stability, lateral control, and directional control are provided.
Date: December 1948
Creator: Lockwood, Vernard E. & Watson, James M.
Partner: UNT Libraries Government Documents Department

Flight measurements of the longitudinal stability, stalling, and lift characteristics of an airplane having a 35 degrees sweptback wing without slots and with 40-percent-span slots and a comparison with wind-tunnel data

Description: Report presenting flight measurements at low speeds to determine the static longitudinal stability, stalling, and lift characteristics of an airplane with a wing sweptback 35 degrees at the quarter-chord line. The airplane was tested without slots on the wing and with slots extending from 40 to 80 percent of the semispan of the sweptback-wing panels measured from the inboard end. Results regarding the static longitudinal stability, stalling characteristics, and lift characteristics are provided.
Date: August 1948
Creator: Sjoberg, S. A. & Reeder, J. P.
Partner: UNT Libraries Government Documents Department

Flight measurements of the stability, control, and stalling characteristics of an airplane having a 35 degree sweptback wing without slots and with 80-percent-span slots and a comparison with wind-tunnel data

Description: Report presenting flight measurements to determine the low-speed flying qualities of an airplane with a wing sweptback 35 degrees at the quarter-chord line. The lateral and directional stability and control characteristics of the airplane without slots and with 80-percent-span slots on the wing are provided.
Date: November 1948
Creator: Sjoberg, S. A. & Reeder, J. P.
Partner: UNT Libraries Government Documents Department

Flight measurements of the lateral and directional stability and control characteristics of an airplane having a 35 degree sweptback wing with 40-percent-span slots and a comparison with wind-tunnel data

Description: Report presenting flight tests conducted to determine the lateral and directional stability and control characteristics of an airplane on which the wing panels are swept back 35 degrees. The wings were equipped with slots extending from 40 to 80 percent of the span of the sweptback wing panels measured from the inboard end. Results regarding the steady sideslips, dynamic directional stability, rudder kicks, and aileron rolls are provided.
Date: January 1948
Creator: Sjoberg, S. A. & Reeder, J. P.
Partner: UNT Libraries Government Documents Department

Bearing tests of 14S sheet and plate

Description: From Summary: "Tests were made to determine bearing yield and ultimate strengths of bare and Alclad 15S-W(exp 1) and 14S-T(exp 1) sheet and plate in thicknesses of 0.064 inch, 0.250 inch, and 0.750 inch. From the results of these tests it was concluded that the ratios of bearing to tensile properties from the with-grain direction were essentially the same as proposed in NACA TN Nos. 901, 920, 974, and 981 for other high-strength aluminum-alloy sheet and plate."
Date: August 1948
Creator: Moore, R. L.
Partner: UNT Libraries Government Documents Department

An Investigation of Aircraft Heaters 26: Development of a Sensitive Plated-Type Thermopile for Measuring Radiation

Description: Report presenting an analysis of the factors determining the power efficiency of radiation thermopiles of the type in which receivers consist of parts of conducts themselves or of coatings or other electrically insulating materials in intimate contact with the conductors. Criterions for maximum power efficiency are calculated for these thermopiles, which can then be applied to general thermopile designs.
Date: July 1948
Creator: Boelter, L. M. K.; Dempster, E. R.; Bromberg, R. & Gier, J. T.
Partner: UNT Libraries Government Documents Department