24 Matching Results

Search Results

open access

High-Altitude Cooling 1: Resume of the Cooling Problem

Report presenting a paper in a series about the cooling of aircraft-engine installations with special reference to the difficulties of cooling at high altitudes. This particular paper discusses the properties of NACA standard air and Army summer air, with corresponding stagnation conditions for a range of flight speed, as summarized in tables and figures.

Date: September 1944

Creator: Silverstein, Abe

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Tests of Propeller-Speed Cooling Blowers

Report presenting testing of cooling blowers for air-cooled engine installations and an exploration of the methods used in the blower design and operating characteristics of the blowers over a range of flight speeds and altitudes. The results indicate that the blowers operate as a more efficient type of propeller cuff and in many cases provide considerably more pressure boost than using a cuff.

Date: July 1942

Creator: Silverstein, Abe

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Experiments on the Recovery of Waste Heat in Cooling Ducts, Special Report

Tests have been conducted in the N.A.C.A. full-scale wind tunnel to investigate the partial recovery of the heat energy which is apparently wasted in the cooling of aircraft engines. The results indicate that if the radiator is located in an expanded duct, a part of the energy lost in cooling is recovered; however, the energy recovery is not of practical importance up to airplane speeds of 400 miles per hour. Throttling of the duct flow occurs with heated radiators and must be considered in des… more

Date: May 1939

Creator: Silverstein, Abe

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Scale Effect on Clark Y Airfoil Characteristics From NACA Full-Scale Wind-Tunnel Tests

This report presents the results of wind tunnel tests conducted to determine the aerodynamic characteristics of the Clark Y airfoil over a large range of Reynolds numbers. Three airfoils of aspect ratio 6 and with 4, 6, and 8 foot chords were tested at velocities between 25 and 118 miles per hour, and the characteristics were obtained for Reynolds numbers (based on the airfoil chord) in the range between 1,000,000 and 9,000,000 at the low angles of attack, and between 1,000,000 and 6,000,000 at… more

Date: June 14, 1934

Creator: Silverstein, Abe

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Aerodynamic Characteristics of Horizontal Tail Surfaces

From Summary: "Collected data are presented on the aerodynamic characteristics of 17 horizontal tail surfaces including several with balanced elevators and two with end plates. Curves are given for coefficients of normal force, drag, and elevator hinge moment. A limited analysis of the results has been made. The normal-force coefficients are in better agreement with the lifting-surface theory of Prandtl and Blenk for airfoils of low aspect ratio than with the usual lifting-line theory. Only par… more

Date: 1940

Creator: Silverstein, Abe & Katzoff, S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Design Charts for Predicting Downwash Angles and Wake Characteristics Behind Plain and Flapped Wings

"Equations and design charts are given for predicting the downwash angles and the wake characteristics for power-off conditions behind plain and flapped wings of the types used in modern design practice. The downwash charts cover the cases of elliptical wings and wings of taper ratios 1, 2, 3, and 5, with aspect ratios of 6, 9, and 12, having flaps covering 0, 40, 70, and 100 percent of the span. Curves of the span load distributions for all these cases are included" (p. 1).

Date: July 14, 1938

Creator: Silverstein, Abe & Katzoff, S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Experimental Investigation of Wind-Tunnel Interference on the Downwash Behind an Airfoil

"The interference of the wind-tunnel boundaries on the downwash behind an airfoil has been experimentally investigated and the results have been compared with the available theoretical results for open-throat wind tunnels. As in previous studies, the simplified theoretical treatment that assumes the test section to be an infinite free jet has been shown to be satisfactory at the lifting line. The experimental results, however, show that this assumption may lead to erroneous conclusions regardin… more

Date: June 4, 1937

Creator: Silverstein, Abe & Katzoff, S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Experimental Verification of the Theory of Wind-Tunnel Boundary Interference

"The results of an experimental investigation on the boundary-correction factor are presented in this report. The values of the boundary-correction factor from the theory, which at the present time is virtually completed, are given in the report for all conventional types of tunnels. With the isolation of certain disturbing effects, the experimental boundary-correction factor was found to be in satisfactory agreement with the theoretically predicted values, thus verifying the soundness and suff… more

Date: May 18, 1933

Creator: Theodorsen, Theodore & Silverstein, Abe

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Development of Cowling for Long-Nose Air-Cooled Engine in the NACA Full-Scale Wind Tunnel

"An investigation of cowlings for long-nose radial engines was made on the Curtiss XP-42 fighter in the NACA full-scale wind tunnel. The unsatisfactory aerodynamic characteristics of all the cowlings with scoop inlets tested led to the development of the annular high-velocity inlet cowlings. Tests showed that ratio of cooling-air velocity at cowling inlet to stream velocity should not be less than 0.5 for this type of cowling and that critical compressibility speed can be extended to more than … more

Date: October 1941

Creator: Silverstein, Abe & Guryansky, Eugene R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Full scale span load distribution on a tapered wing with split flaps of various spans

Pressure-distribution tests were conducted in the full-scale wind tunnel on a 2:1 tapered U.S.A. 45 airfoil equipped with 20 percent chord split trailing-edge flaps of various spans. A special installation was employed in the tests utilizing a half-span airfoil mounted vertically above a reflection plane. The airfoil has a constant chord center section and rounded tips and is tapered in thickness from 18 percent c at the root to 9 percent c at the tip. The aerodynamic characteristics, given by … more

Date: February 1937

Creator: Parsons, John F. & Silverstein, Abe

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Liquid Hydrogen as a Jet Fuel for High-Altitude Aircraft

Memorandum presenting a review of some of the analytical and experimental studies of the use of liquid hydrogen as a jet-engine fuel and which show the possible extension of aircraft performance that will follow adequate research and development effort on the problem of its use.

Date: April 15, 1955

Creator: Silverstein, Abe & Hall, Eldon W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Drag Analysis of Single-Engine Military Airplanes Tested in the NACA Full-Scale Wind Tunnel

Report presenting tests in the full-scale wind tunnel on 11 single-engine military airplanes to investigate methods for increasing their high speed. Results regarding the power-plant installation, flow characteristics, wings, cockpit canopies, landing gear, and air leakage are provided.

Date: October 1940

Creator: Dearborn, C. H. & Silverstein, Abe

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Experimental Verification of the Theory of Oscillating Airfoils

"Measurements have been made of the lift on an airfoil in pitching oscillation with a continuous-recording, instantaneous-force balance. The experimental values for the phase difference between the angle of attack and the lift are shown to be in close agreement with theory" (p. 619).

Date: April 24, 1939

Creator: Silverstein, Abe & Joyner, Upshur T.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Preliminary Full-Scale Wind-Tunnel Investigation of Wing Ducts for Radiators, Special Report

"Wing ducts for liquid-cooled engine radiators have been investigated in the N.A.C.A. full-scale wind tunnel on a large model airplane. The tests were made to determine the relative merits of several types of duct and radiator installations for an airplane of a particular design. In the test program the principal duct dimensions were systematically varied, and the results are therefore somewhat applicable to the general problems of wing duct design, although they should be considered as prelimi… more

Date: March 1938

Creator: Silverstein, Abe & Nickle, F. R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Determination of boundary-layer transition on three symmetrical airfoils in the NACA full-scale wind tunnel

For the purpose of studying the transition from laminar to turbulent flow, boundary-layer measurements were made in the NACA full-scale wind tunnel on three symmetrical airfoils of NACA 0009, 0012, and 0018 sections. The effects of variations in lift coefficient, Reynolds number, and airfoil thickness on transition were investigated. Air speed in the boundary layer was measured by total-head tubes and by hot wires; a comparison of transition as indicated by the two techniques was obtained. The … more

Date: May 26, 1938

Creator: Silverstein, Abe & Becker, John V.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Ground-Handling Forces on a 1/40-Scale Model of the U. S. Airship "Akron"

This report presents the results of full-scale wind tunnel tests conducted to determine the ground-handling forces on a 1/40-scale model of the U. S. Airship "Akron." Ground-handling conditions were simulated by establishing a velocity gradient above a special ground board in the tunnel comparable with that encountered over a landing field. The tests were conducted at Reynolds numbers ranging from 5,000,000 to 19,000,000 at each of six angles of yaw between 0 degree and 180 degrees and at four … more

Date: 1936

Creator: Silverstein, Abe & Gulick, B. G.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Wind-Tunnel Interference With Particular Reference to Off-Center Positions of the Wing and to the Downwash at the Tail

"The theory of wind tunnel boundary influence on the downwash from a wing has been extended to provide more complete corrections for application to airplane test data. The first section of the report gives the corrections of the lifting line for wing positions above or below the tunnel center line; the second section shows the manner in which the induced boundary influence changes with distance aft of the lifting line. Values of the boundary corrections are given for off-center positions of the… more

Date: June 28, 1935

Creator: Silverstein, Abe & White, James A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Drag and Propulsive Characteristics of Air-Cooled Engine-Nacelle Installations for Large Airplane

"An investigation was conducted in the NACA full-scale wind tunnel to determine the drag and the propulsive efficiency of nacelle-propeller arrangements for a large range of nacelle sizes. In contrast with usual tests with a single nacelle, these tests were conducted with nacelle-propeller installations on a large model of a four-engine airplane. Data are presented on the first part of the investigation, covering seven nacelle arrangements with nacelle diameters from 0.53 to 1.5 times the wing … more

Date: 1942

Creator: Silverstein, Abe & Wilson, Herbert A., Jr.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Cooling in Cruising Flight With Low Fuel-Air Ratios

Report presenting testing of a Pratt & Whitney R-1830-43 engine mounted in a B-24D nacelle in the full-scale wind tunnel in order to investigation the potential improvements of fuel economy. Suggestions for improving the cruising power and cruising range by operating at specified fuel-air ratios are provided.

Date: June 1942

Creator: Silverstein, Abe & Wilson, Herbert A., Jr.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Aerodynamic Characteristics of a 4-Engine Monoplane Showing Comparison of Air-Cooled and Liquid-Cooled Engine Installations

From Introduction: "An investigation has been conducted in the N.A.C.A. full-scale wind tunnel to determine the aerodynamic characteristics of a 1/4-scale model of a 4-engine monoplane when equipped with comparable air-cooled engine and liquid-cooled engine installations. The air-cooled engine installation consisted of nacelles equipped with N..A.C.A. cowlings and oil coolers located in the leading edge of the wing."

Date: July 1939

Creator: Silverstein, Abe & Wilson, Herbert A., Jr.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Aerodynamic Characteristics of a 4-Engine Monoplane Showing Effects of Enclosing the Engines in the Wing and Comparisons of Tractor- and Pusher-Propeller Arrangements

Report presenting testing in the full-scale wind tunnel on a model of a large 4-engine monoplane to determine the overall aerodynamic efficiency of a conventional wing-nacelle-engine installation as compared with power-plant installations enclosed in the wing with extension shafts to the propellers. Results regarding power-on and power-off performance for the installations as well as propeller noise are provided.

Date: April 1938

Creator: Silverstein, Abe & Wilson, Herbert A., Jr.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Drag and Propulsive Characteristics of Air-Cooled Engine-Nacelle Installations for Large Airplanes, Special Report

"An investigation is in progress in the NACA full-scale wind tunnel to determine the drag and propulsive efficiency of nacelle sizes. In contrast with the usual tests with a single nacelle, these tests were conducted with nacelle-propeller installations on a large model of a 4-engine airplane. Data are presented on the first part of the investigation, covering seven nacelle arrangements with nacelle diameters from 0.53 to 1.5 times the wing thickness" (p. 1).

Date: August 1939

Creator: Silverstein, Abe & Wilson, Herbert A., Jr.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Downwash and Wake Behind Plain and Flapped Airfoils

"Extensive experimental measurements have been made of the downwash angles and the wake characteristics behind airfoils with and without flaps and the data have been analyzed and correlated with the theory. A detailed study was made of the errors involved in applying lifting-line theory, such as the effects of a finite wing chord, the rolling-up of the trailing vortex sheet, and the wake. The downwash angles, as computed from the theoretical span load distribution by means of the Biot-Savart eq… more

Date: June 23, 1938

Creator: Silverstein, Abe; Katzoff, S. & Bullivant, W. Kenneth

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Comparative Flight and Full-Scale Wind-Tunnel Measurements of the Maximum Lift of an Airplane

"Determinations of the power-off maximum lift of a Fairchild 22 airplane were made in the NACA full-scale wind tunnel and in flight. The results from the two types of test were in satisfactory agreement. It was found that, when the airplane was rotated positively in pitch through the angle of stall at rates of the order of 0.1 degree per second, the maximum lift coefficient was considerably higher than that obtained in the standard tests, in which the forces are measured with the angles of atta… more

Date: October 26, 1937

Creator: Silverstein, Abe; Katzoff, S. & Hootman, James A.

Item Type: Report

Partner: UNT Libraries Government Documents Department