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The effect of compressibility on two-dimensional tunnel-wall interference for a symmetrical airfoil

Description: Summary: The effective change in the velocity of flow past a wing section, caused by the presence of wind-tunnel walls, is known for potential flow. This theory is extended by investigation of the two-dimensional compressible flow past a thin Rankine Oval. It is shown that for a symmetrical section at zero angle of attack the velocity increment due to the tunnel walls in the incompressible case must be multiplied by the factor 1/1-M^2 to take account of compressibility effects. The Mach numb… more
Date: May 1943
Creator: Nitzberg, Gerald E.
Partner: UNT Libraries Government Documents Department
open access

An Experimental Investigation of Rectangular Exhaust-Gas Ejectors Applicable for Engine Cooling

Description: Report presenting an experimental investigation of rectangular exhaust-gas ejector pump to provide data that would serve as a guide to the design of ejector applications for aircraft engines with marginal cooling. With a decrease in the quantity of air pumped and an increase in the length of an ejector, the ejector pressure rise increases to optimum values. Results regarding straight ejectors, diffuser ejectors, curved ejectors, ejector aspect ratio, divided ejectors, multistage ejectors, and n… more
Date: May 1945
Creator: Manganiello, Eugene J. & Bogatsky, Donald
Partner: UNT Libraries Government Documents Department
open access

An Investigation of a Thermal Ice-Prevention System for a C-46 Cargo Airplane 5: Effect of Thermal System on Airplane Cruise Performance

Description: Report presenting flight tests conducted to evaluate the effect of a thermal ice prevention system on the aerodynamic performance of a C-46 cargo airplane. The installation of the thermal ice-prevention system was found to reduce the indicated airspeed by about 6 miles per hour. Results regarding the overall performance change resulting from the installation of the thermal system, reduction of power attributed to heat-exchanger exhaust-gas back pressure, reduction of power attributed to the int… more
Date: May 1945
Creator: Selna, James
Partner: UNT Libraries Government Documents Department
open access

An Investigation of a Thermal Ice-Prevention System for a C-46 Cargo Airplane 6: Dry-Air Performance of Thermal System at Several Twin- and Single-Engine Operating Conditions at Various Altitudes

Description: Report presenting flight tests to establish the dry-air-performance characteristics of a thermal ice-prevention system at various operating conditions and altitudes. Results regarding twin-engine tests and single-engine tests of characteristics such as skin temperatures and location of heating are provided.
Date: May 1945
Creator: Selna, James & Kees, Harold L.
Partner: UNT Libraries Government Documents Department
open access

Full-scale tunnel investigation of the pressure distribution over the tail of the P-47B airplane

Description: Report presenting measurements made of the pressures of the tail surfaces of the Republic Aviation Corporation P-47B airplane in the full-scale tunnel. Pressures were measured over the horizontal and vertical tail surfaces for several angles of attack and angles of yaw with numerous control-surface deflections to provide a check on the design loads. Results regarding the normal-force coefficients and predictions of forces on horizontal tail surfaces are provided.
Date: May 1943
Creator: Dingeldein, Richard C.
Partner: UNT Libraries Government Documents Department
open access

The Porpoising Characteristics of a Planing Surface Representing the Forebody of a Flying-Boat Hull

Description: Porpoising characteristics were observed on V-body fitted with tail surfaces for different combinations of load, speed, moment of inertia, location of pivot, elevator setting, and tail area. A critical trim was found which was unaltered by elevator setting or tail area. Critical trim was lowered by moving pivot either forward or down or increasing radius or gyration. Increase in mass and moment of inertia increased amplitude of oscillations. Complete results are tabulated and shown graphically.
Date: May 1942
Creator: Benson, James M.
Partner: UNT Libraries Government Documents Department
open access

A flight investigation of internally balanced sealed ailerons in the presence of a balanced split flap

Description: Report presenting flight tests made with a modified Ryan ST airplane to determine the effect on aileron characteristics of various arrangements of balanced split flaps covering that portion of the wing span occupied by the ailerons. With the flaps fully extended, the aileron effectiveness was reduced by approximately 18 percent of the effectiveness measured with ailerons alone.
Date: May 1942
Creator: Williams, W. C.
Partner: UNT Libraries Government Documents Department
open access

Formulas for propellers in yaw and charts of the side-force derivative

Description: Report presenting formulas for propellers for the rate of change of side-force coefficient with angle of yaw and for the rate of change of pitching-moment coefficient with angle of yaw. Charts of side-force derivatives are given for two propellers of different plan forms.
Date: May 1943
Creator: Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department
open access

Effect of Oil Flow to Piston on Piston-Ring Sticking and Oil Consumption in a Single-Cylinder Engine

Description: Report presenting an investigation to determine the effect of the amount of oil flow to the piston on the ring-sticking characteristics of a piston and ring assembly and on the engine oil consumption. Results regarding the blow-by, lubrication, oil consumption, and method of supplying oil are provided.
Date: May 1945
Creator: Tauschek, Max J.; Corrington, Lester C. & Meigs, John B.
Partner: UNT Libraries Government Documents Department
open access

Effect of inlet-air velocity distribution on the metering pressure of an injection-type aircraft carburetor

Description: Report presenting tests of a three-barrel pressure carburetor to determine the effect of nonuniformity of the air flow in the intake duct on the metering of the carburetor. Measurements were made in the air side of the metering system and in the carburetor barrels for a variety of flow distributions. Results regarding the metering pressure, altitude compensation, effect of throttle on the metering characteristics, and flow of air around the bends are provided
Date: May 1942
Creator: Kinghorn, George F.
Partner: UNT Libraries Government Documents Department
open access

Method of Calculating Performance of Dual-Rotating Propellers From Airfoil Characteristics

Description: "A method is developed for calculating the performance of a dual-rotating propeller from the section characteristics of the blade elements. The method is applied to an eight-blade dual-rotating propeller and the computed results are compared with low-speed wind-tunnel tests of the same propeller in both the tractor and pusher positions. The computations are found to agree within the experimental accuracy of the measurements" (p. 1).
Date: May 1943
Creator: Naiman, Irven
Partner: UNT Libraries Government Documents Department
open access

Investigation of Effect of Sideslip on Lateral Stability Characteristics 1: Circular Fuselage with Variations in Vertical-Tail Area and Tail Length With and Without Horizontal Tail Surface

Description: Report presenting the results of tests of a circular fuselage with various combinations of tail lengths and vertical tail surfaces with and without the horizontal tail surface in the 6- by 6-foot test section of the stability tunnel in the form of diagrams of variation of coefficients of lateral force and yawing moment with angle of yaw and angle of attack.
Date: May 1944
Creator: Fehlner, Leo F. & MacLachlan, Robert
Partner: UNT Libraries Government Documents Department
open access

A flight investigation of short-period longitudinal oscillations of an airplane with free elevator

Description: Report presenting a flight investigation to check the results of a theoretical analysis of longitudinal stability of an airplane with free controls. Tests used a Fairchild XR2K-1 airplane on which the weight moment and the aerodynamic balance of the elevator were varied to bring it into a condition where unstable short-period oscillations were encountered.
Date: May 1942
Creator: Phillips, William H.
Partner: UNT Libraries Government Documents Department
open access

An Electromagnetic-Analogy Method of Solving Lifting-Surface-Theory Problems

Description: Report presenting a method for making lifting-surface calculations by means of magnetic measurements of an electromagnetic-analogy model. The method is based on the perfect analogy between the strength of the magnetic field around a conductor and the strength of the induced-velocity field around a vortex.
Date: May 1945
Creator: Swanson, Robert S. & Crandall, Stewart M.
Partner: UNT Libraries Government Documents Department
open access

Jet-boundary corrections for reflection-plane models in rectangular wind tunnels

Description: Report presenting a detailed method for determining the jet-boundary corrections for reflection-plane models in rectangular wind tunnels. The principal effects of aerodynamic induction and boundary-induced curvature of the streamlines are considered. An example is included to illustrate the method.
Date: May 1943
Creator: Swanson, Robert S. & Toll, Thomas A.
Partner: UNT Libraries Government Documents Department
open access

An Instrument for the Determination of Rain Densities in Flight

Description: Report presenting an investigation to develop an instrument for the determination of rain densities in this range in flight. The major requirements for the instrument are ease of operation, minimum weight and bulk, rapid response, and simplicity of installation.
Date: May 1943
Creator: Bemis, John R. & Houghton, Henry G., Jr.
Partner: UNT Libraries Government Documents Department
open access

Lead susceptibility of paraffins, cycloparaffins, and olefins

Description: "General relationships for the lead susceptibilities of paraffins, cycloparaffins, and olefins are presented. Methods are described by which the lead response may be estimated for these hydrocarbon classes, whether the lead response is indicated by octane number, critical compression ratio, or indicated mean effective pressure as limited by knock" (p. 1).
Date: May 1943
Creator: Barnett, Henry C.
Partner: UNT Libraries Government Documents Department
open access

Engine Tests of Pressurized Shunt-Type Cooling Systems for a Liquid-Cooled Engine

Description: Report presenting tests conducted to determine the performance of two pressurized shunt-type cooling systems for liquid-cooled aircraft engines using a mixture of 30 percent AN-E-2 ethylene glycol and 70 percent water as the coolant. Results regarding effect of engine speed on coolant-flow rate, effect of expansion-tank pressure on coolant-flow rate, relation between pump-inlet pressure and expansion-tank pressure, variation of coolant-flow rate with pump-inlet pressure, flow rate through the s… more
Date: May 1945
Creator: Manganiello, Eugene J.; Lundin, Bruce T. & Povolny, John H.
Partner: UNT Libraries Government Documents Department
open access

Wind-tunnel tests of dual-rotating propellers with systematic differences in number of blades, blade setting, and rotational speed of front and rear propellers

Description: Report presenting the results of aerodynamic tests of seven-blade propellers which were considered as a possible arrangement to avoid vibration difficulties. Variations of relative blade angle and rotational speeds of the front and rear components of a six-blade dual-rotating propeller were also investigated.
Date: May 1944
Creator: Gray, W. H.
Partner: UNT Libraries Government Documents Department
open access

Tests and Approximate Analysis of Bending Stresses Due to Torsion in a D-Section Box

Description: "Strain surveys were made on the stringers reinforcing a D-section box loaded in torsion and restrained from warping at the root. On the basis of the tests, a procedure is suggested for estimating the bending stresses due to torsion that occur near the flange of a D-section box. A similar test of a triangular-section box showed that for such a section there were no significant bending stresses due to torsion, a fact which was also shown theoretically" (p. 1).
Date: May 1944
Creator: Duberg, John E. & Brilmyer, Harold G.
Partner: UNT Libraries Government Documents Department
open access

Column and Plate Compressive Strengths of Aircraft Structural Materials: Extruded 14S-T Aluminum Alloy

Description: "Column and plate compressive strengths of extruded 14S-T aluminum alloy were determined both within and beyond the elastic range from tests of flat-end H-section columns and from local-instability tests of H-, Z-, and channel-section columns. These tests are part of an extensive research investigation to provide data on the structural strength of various aircraft materials. The results are presented in the form of curves and charts that are suitable for use in the design and analysis of aircra… more
Date: May 1946
Creator: Heimerl, George J. & Niles, Donald E.
Partner: UNT Libraries Government Documents Department
open access

The Use of a Retractable Planing Flap Instead of a Fixed Step on a Seaplane

Description: Report presents and discusses the improvements in hydrodynamic and aerodynamic performance of a seaplane with a retractable planing flap instead of a conventional main step. A type of flap that could be used is described and tested for hydrodynamic stability. Results regarding the trim limits of stability, limiting positions of the center of gravity, and skipping are provided.
Date: May 1943
Creator: Benson, James M. & Lina, Lindsay J.
Partner: UNT Libraries Government Documents Department
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