UNT Libraries Government Documents Department - 18 Matching Results

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Charts for estimation of the characteristics of a helicopter rotor in forward flight I: profile drag-lift ratio for untwisted rectangular blades

Description: Report presenting charts showing the rotor profile drag-lift ratio for a helicopter rotor operating in forward flight and having hinged rectangular untwisted blades. The charts are given for a range of power input covering glides, level flight, and moderate rates of climb. A drag curve was used for preparing the charts, and the curve is compared with experimental curves for typical airfoils.
Date: August 1944
Creator: Bailey, F. J., Jr.

Charts for Helicopter-Performance Estimation

Description: Report presenting charts relating helicopter aerodynamic design variables to performance in steady powered flight. The flight conditions covered are hovering, climb, and horizontal flight. The use of the charts is illustrated by numerical examples in order that computations can be made for particular problems.
Date: August 1945
Creator: Talkin, Herbert W.

Compressibility Effects in Aeronautical Engineering

Description: "Compressible-flow research, while a relatively new field in aeronautics, is very old, dating back almost to the development of the first firearm. Over the last hundred years, researches have been conducted in the ballistics field, but these results have been of practically no use in aeronautical engineering because the phenomena that have been studied have been the more or less steady supersonic condition of flow. Some work that has been done in connection with steam turbines, particularly nozzle studies, has been of value, In general, however, understanding of compressible-flow phenomena has been very incomplete and permitted no real basis for the solution of aeronautical engineering problems in which.the flow is likely to be unsteady because regions of both subsonic and supersonic speeds may occur" (p. 1).
Date: August 1941
Creator: Stack, John

Effect of Helicopter Performance of Modifications in Profile-Drag Characteristics of Rotor-Blade Airfoil Sections

Description: Rough conventional, smooth conventional, and laminar-flow or low-drag sections were tested. The items covered are rotor thrust for fixed power in hovering, range and endurance at cruising speed, and power required at high-forward speed. Calculations indicated that a smooth conventional section gives marked performance gains. Smaller gains are obtainable by using a low-drag section. At high speeds or loads the low-drag section is inferior to the smooth conventional section.
Date: August 1944
Creator: Gustafson, F. B.

The Effects of Roughness at High Reynolds Numbers on the Lift and Drag Characteristics of Three Thick Airfoils

Description: "In connection with studies of airfoils applicable to large high-speed aircraft, the effects of roughness on three 22-percent-thick airfoils were investigated. The tests were made over a range of Reynolds number from about 6 to 26 x 10(exp 6) for the airfoils smooth and with roughness strips applied to the surfaces. The results indicated that for the roughened models the scale effect was generally favorable" (p. 1).
Date: August 1944
Creator: Abbott, Frank T., Jr. & Turner, Harold R., Jr.

Engine and inspection tests of methyl tert-butyl ether as a component of aviation fuel

Description: Report presenting an investigation of the suitability of methyl tert-butyl ether as a component of aviation fuel from considerations of knock-limited performance tests and laboratory inspection tests. Data were obtained from testing on the 17.6 engine under supercharged conditions with fuel blends containing 10 and 20 percent methyl tert-butyl ether. Results regarding small-scale-engine data, full-scale-engine data, and inspection data are provided.
Date: August 1944
Creator: Barnett, Henry C.; Meyer, Carl L. & Jones, Anthony W.

High-speed drag tests of several fuselage shapes in combination with a wing

Description: Drag testing was conducted in the high-speed wind tunnel of 23 conditions combining six streamline shapes and three conventional cowling-fuselage bodies. All of the models were tested in combination with a wing in order to include wing-fuselage interference effects. The critical speeds of combinations tested were, in general, determined by the wing-fuselage juncture.
Date: August 1940
Creator: Draley, Eugene C.

The NACA Impact Basin and Water Landing Tests of a Float Model at Various Velocities and Weights

Description: Report presenting data obtained when a float with both horizontal and vertical velocity contact on a water surface. The report is confined to a presentation of the relationship between resultant velocity and impact normal acceleration for various float weights when all other parameters are constant.
Date: August 1944
Creator: Batterson, Sidney A.

Scale and Turbulence Effects on the Lift and Drag Characteristics of the NACA 65(Sub 3)-418, A=1.0 Airfoil Section

Description: Wind-tunnel tests, investigating low drag wing performance in small-scale tests, showed a large increase in minimum drag coefficient, and a decrease of maximum lift coefficient occurred with decreasing Reynolds Number above certain designated values. The lift-curve slope varied up to 6% between high and low turbulence levels. Low Reynolds Number test data are unreliable for low drag airfoils either to estimate full-scale characteristics or to determine merits of airfoils for higher Reynolds numbers.
Date: August 1944
Creator: Tucker, Warren A. & Quinn, John H.

A simple method for estimating terminal velocity including effect of compressibility on drag

Description: Report presenting a generalized drag curve providing an estimate for the drag rise due to compressibility as obtained from an analysis of wind-tunnel data of several airfoils, fuselages, nacelles, and windshields at speeds up to and above the wing critical speed. Results regarding drag characteristics and terminal-velocity calculation are provided.
Date: August 1945
Creator: Bielat, Ralph P.

Supercharged-Engine Knock Tests of Methyl Tert-Butyl Ether

Description: Report presenting data that show the knock-limited performance of methyl tert-butyl ether obtained from tests made in a 17.6-cubic-inch-displacement engine under supercharged conditions. Tests for temperature sensitivity, speed sensitivity, and lead susceptibility were made on a blend of 20 percent methyl tert-butyl ether and 80 percent S-2 reference fuel.
Date: August 1944
Creator: Barnett, Henry C. & Slough, James W., Jr.

Wind Tunnel Tests of Ailerons at Various Speeds 4: Ailerons of 0.20 Airfoil Chord and True Contour With 0.35 Aileron-Chord Extreme Blunt-Nose Balance on the NACA 23012 Airfoil

Description: Report presenting tests made on an NACA 23012 airfoil fitted with a 20-percent-chord, true-contour aileron with 35-percent-chord, extreme blunt-nose balance. The primary purpose of the investigation was to determine the variation of the aerodynamic characteristics of this type of aileron with airspeed; the effect of variations of gap width and balance-nose radii was also investigated. Results regarding hinge moments, lift, and pitching-moment coefficients are provided.
Date: August 1943
Creator: Anderson, R. A.

Wind-Tunnel Tests of Several Arrangements of External Auxiliary Fuel Tanks on a Fighter-Type Airplane

Description: Report presenting an investigation conducted in the 19-foot pressure tunnel to determine the aerodynamic effects of several arrangements of external auxiliary fuselage and wing tanks of large fuel capacity on a fighter-type airplane. The rectangular tank arrangement of 350-gallon fuel capacity has the greatest adverse aerodynamic effect on the airplane and is the least desirable of all the configurations tested.
Date: August 1942
Creator: Pepper, Edward