Search Results

open access

An Analytical Investigation of the Effects of Elevator-Fabric Distortion on the Longitudinal Stability and Control of an Airplane

Description: From Summary: "The results of an analytical investigation to determine the qualitative effects of elevator-fabric distortion on the stick-force characteristics of an airplane are presented. These results indicate that serious alteration of intended stick-force characteristics can be produced by elevator-fabric distortion."
Date: May 1944
Creator: Mathews, Charles W.
open access

Cascade investigation of buckets for a modern aircraft turbosupercharger

Description: Report presenting a cascade investigation in two-dimensional flow in the 5-inch cascade tunnel and the 1-inch turbine-element testing apparatus to obtain a satisfactory bucket design for use in a modern aircraft turbosupercharger. Results regarding the root sections, pitch sections, and tip sections are provided.
Date: November 1944
Creator: Kantrowitz, Arthur & Erwin, John R.
open access

Charts for Determining Propeller Efficiency

Description: Report presenting a description of a short method of estimating propeller efficiency for a given operating condition. The efficiency is determined for any design condition by evaluating separately from charts the induced losses and the profile-drag losses. The report covers single-rotating propellers of two, three, four, six, and eight blades and includes charts showing the rotational-energy loss for the given operating condition.
Date: September 1944
Creator: Crigler, John L. & Talkin, Herbert W.
open access

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.
open access

Charts for the determination of wing torsional stiffness required for specified rolling characteristics or aileron reversal speed

Description: "A series of charts are presented by which the wing torsional stiffness required to meet a given standard of rolling effectiveness may be quickly determined. The charts may also be used to obtain quickly the aileron reversal speed and the variation of the loss in rolling effectiveness with airspeed. The charts apply to linearly tapered wings and elliptical wings of tubular-shell construction having various aspect ratios with aileron span and location of ailerons as variables" (p. 457).
Date: December 1944
Creator: Pearson, Henry A. & Aiken, William S., Jr.
open access

Collection of Balanced-Aileron Test Data

Description: "Test data of balanced ailerons have been collected from NACA and British sources. These data, which are presented in the form of charts, are grouped as A - ailerons with Frise balances, B - ailerons with blunt-nose balances, C - ailerons with internal balances, D - ailerons with contour modifications, and E - ailerons with tabs. Results of flight tests and of wind-tunnel tests in both two- and three-dimensional flow are presented but no correlation nor resume of the data has been included" (p.… more
Date: January 1944
Creator: Rogallo, F. M.
open access

Comparison of calculated and experimental propeller characteristics for four-, six-, and eight-blade single-rotating propellers

Description: Report presenting the calculated performance of four-, six-, and eight-blade single-rotating propellers compared with experimental results for blade angles ranging from 25 to 65 degrees. The data were obtained on propellers mounted in front of a streamline body with a spinner housing the hub.
Date: February 1944
Creator: Crigler, John L.
open access

Comparison of Yaw Characteristics of a Single-Engine Airplane Model With Single-Rotating and Dual-Rotating Propellers

Description: Report presenting testing in the pressure tunnel to determine the yaw characteristics of a scale model of a single-engine, fighter-type airplane with six-blade single-rotating and dual-rotating propellers. Force and moment characteristics are presented for several model and power conditions.
Date: April 1944
Creator: Neely, R. H.; Fogarty, L. E. & Alexander, S. R.
open access

A Concise Theoretical Method for Profile-Drag Calculation; Advance Report

Description: In this report a method is presented for the calculation of the profile drag of airfoil sections. The method requlres only a knowledge of the theoretical velocity distribution and can be applied readily once this dlstribution is ascertained. Comparison of calculated and experimental drag characteristics for several airfoils shows a satisfactory agreement. Sample calculatlons are included.
Date: February 1944
Creator: Nitzberg, Gerald E.
open access

Considerations of wake-excited vibratory stress in a pusher propeller

Description: Report presenting an equation based on simple blade-element theory and the assumption of a fixed wake pattern is derived and fitted to available data to show the first-order relation between the parameters of propeller operation and intensity of wake-excited periodic force acting on the blades of a pusher propeller. The derived equation indicates that the effect of power coefficient on the intensity of the wake-excited periodic force is small. Limited data also indicates that the wake-excited v… more
Date: February 1944
Creator: Corson, Blake W., Jr.
open access

Cooling Characteristics of a Pratt and Whitney R-2800 Engine Installed in an NACA Short-Nose High-Inlet-Velocity Cowling

Description: An investigation was made of the cooling characteristics of a P and W R-2800 engine with NACA short-nose high inlet-velocity cowling. The internal aerodynamics of the cowling were studied for ranges of propeller-advance ratio and inlet-velocity ratio obtained by deflection of cowling flaps. Tests included variations of engine power, fuel/air ratio and cooling-air pressure drop. Engine cooling data are presented in the form of cooling correlation curves, and an example for calculation of cooling… more
Date: June 1944
Creator: Corson, Blake W. & McLellan, Charles H.
open access

Correlation of flight data on limit pressure coefficients and their relation to high-speed burbling and critical tail loads

Description: Report presenting flight data, which shows that the absolute minimum or limit pressure coefficient on an airfoil is a function mainly of the Mach number for Mach numbers above about 0.3 and for usual flight values of the Reynolds number. The curve of limit pressure coefficient as a function of Mach number is established.
Date: September 1944
Creator: Rhode, Richard V.
open access

The Determination of Span Load Distribution at High Speeds by Use of High-Speed Wind-Tunnel Section Data

Description: Report presenting a tabular method for determining the span load distribution at high Mach numbers by utilizing high-speed airfoil section data. This method, which is also called the generalized method, is an easily applied process of successive approximations by which a general application of the lifting-line theory may be used to determine the span load distribution for wings composed of sections with arbitrary lift curves. An example is provided to show how the method is used.
Date: February 1944
Creator: Boshar, John
open access

Effect of a Trailing-Edge Extension on the Characteristics of a Propeller Section

Description: Report presenting a convenient technical method to evaluate changes in the airfoil characteristics resulting from an extension of the chord at the trailing edge of a propeller blade section. The method determines the change in the angle of zero lift, the ideal angle of attack, and the difference in these angles as a function of the angle and length of the trailing-edge extension.
Date: September 1944
Creator: Theodorsen, Theodore & Stickle, George W.
open access

Effect of Compressibility on Pressure Distribution Over an Airfoil With a Slotted Frise Aileron

Description: Pressure distribution measurements were made over an airfoil with slotted Frise aileron up to 0.76 Mach at various angles of attack and aileron defections. Section characteristics were determined from these pressure data. Results indicated loss of aileron rolling power for deflections ranging from -12 Degrees to -19 Degrees.
Date: July 1944
Creator: Luoma, Arvo A.
open access

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.
open access

Effect of tilt of the propeller axis on the longitudinal-stability characteristics of single-engine airplanes

Description: Report presenting the results of tests of a model of a single-engine airplane with two different tilts of the propeller axis. The results indicate that on a typical design, a 5 degree downward tilt of the propeller axis will considerably reduce the destabilizing effects of power.
Date: November 1944
Creator: Goett, Harry J. & Delany, Noel K.
open access

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.
open access

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.
open access

Estimation of Pressure Distributions at Subcritical Speeds for Turrets Located on a Wing

Description: Report presenting the use of current methods that include interference and compressibility effects to estimate pressures over and near turrets located on a wing in regions of high interference velocities. The agreement between measured and estimated pressures indicated that present methods are adequate for predicting approximate critical speeds and for estimating loads at subcritical speeds with sufficient accuracy for design purposes.
Date: July 1944
Creator: Ritchie, Virgil S. & Daniels, Everett J.
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