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Effect of NACA Injection Impeller and Ducted Head Baffles on Flight Cooling Performance of Double-Row Radial Engine in Four-Engine Heavy Bomber

Description: "The NACA has conducted a flight investigation to improve the cooling characteristics of the installation of a double-row radial engine. The tests reported herein concern the use of the NACA injection impeller and ducted head baffles in various combinations on both the port inboard and the port outboard engines. The performance of the modified installation was evaluated by comparing it with that of the standard engines" (p. 1).
Date: April 13, 1945
Creator: Marble, Frank E.; Miller, Mahlon A. & Vensel, Joseph R.
Partner: UNT Libraries Government Documents Department
open access

A Cooling Correlation Equation for a Double-Row Radial Engine Based on the Temperature of the Exhaust-Valve Seat

Description: Report discussing a cooling-correlation equation based on the average temperature of exhaust-valve seats of a large double-row radial engine. From the equation, predicts can be made about the cooling-air pressure drop required to cool the critical region of engine cylinders. Using a modified carburetor to improve the fuel-air-ratio distribution to the cylinders increased the accuracy of the equation's predictions.
Date: April 1945
Creator: Jagger, James M. & Black, Fred O., Jr.
Partner: UNT Libraries Government Documents Department
open access

Wind-Tunnel Tests of Four Curtiss Propellers Embodying Different Blade Sections

Description: Tests of four 10-foot propellers were made in the propeller-research tunnel for the Army Air Corps to check flight and static thrust test results made on several propellers embodying Clark Y and modified NACA 16-series sections. These propellers were identical as to diameter and activity factor and very closely identical in thickness ratio and pitch distribution. The blades embodied sections with both single- and double-cambered Clark Y, modified NACA 16-series, and a combination of Clark Y and… more
Date: August 1941
Creator: Gray, W. H.
Partner: UNT Libraries Government Documents Department
open access

Tests of Four Full-Scale Propellers to Determine the Effect of Trailing-Edge Extensions on Propeller Aerodynamic Characteristics

Description: Propellers with trailing-edge extensions were studied to determine aerodynamic characteristics. Trailing-edge extension increased power absorbed by propeller with little loss in efficiency. Power coefficient for maximum efficiency was greater for 20% camber type extension than for 20% straight type extension over range of advance ratio of 1.0 to 2.5 although camber type was less efficient. Efficiency was about the same for cruising and high-speed at a high power coefficient for propeller with e… more
Date: July 1945
Creator: Maynard, Julian D. & Evans, Albert J.
Partner: UNT Libraries Government Documents Department
open access

Power-Off Tests of the Northrop N9M-2 Tailless Airplane in the 40- by 80-Foot Wind Tunnel

Description: Report discussing tests on the N9M-2 airplane to evaluate the airplane efficiency factor and to investigate the characteristics of the aeroboost in the elevon control system. The efficiency factor compared reasonably well to conventional airplanes and the aeroboost system and valve-chatter tests were satisfactory.
Date: December 14, 1944
Creator: Stevens, Victor I., Jr. & McCormack, Gerald M.
Partner: UNT Libraries Government Documents Department
open access

Flight Tests of the High-Speed Performance of a P-51B Airplane (AAF No. 43-12105)

Description: Report discussing testing to check the improvement of 3 or 4 miles per hour in the maximum speed of the P-51B airplane as a result of sealing the wing-gun access doors and flap-spar lightening holes. Large variations in speed were observed during testing, so additional testing and analysis was carried out to determine the effects of various factors that were suspected of contributing to the inconsistency of the plane's performance.
Date: December 18, 1944
Creator: Voglewede, T. J. & Danforth, E. C. B.
Partner: UNT Libraries Government Documents Department
open access

Nitrous Oxide Supercharging of an Aircraft-Engine Cylinder

Description: Report discussing tests to determine the performance of an aircraft engine cylinder using nitrous oxide to provide additional supercharging. The test results of injecting it as a gas and calculated results of injecting it as a liquid are described.
Date: June 26, 1945
Creator: Tauschek, Max J.; Corrington, Lester C. & Huppert, Merle C.
Partner: UNT Libraries Government Documents Department
open access

Static-Thrust Investigation of Full-Scale PV-2 Helicopter Rotors Having NACA 0012.6 and 23012.6 Airfoil Sections

Description: An investigation was conducted to compare the performance of two 25-ft-diam rotors which had identical dimensions and were similar in construction but different in blade airfoil-sections. Tests were conducted at indicated blade pitch angles from 3 degrees to 11.5 degrees and rotor speeds of 200, 290, and 371 rpm. The 23012.6 rotor required 2 percent less power to hover than the 0012.6. At thrust coefficients above design, the performance of the 23012.6 became better than the 0012.6 rotor.
Date: May 1946
Creator: Lipson, Stanley
Partner: UNT Libraries Government Documents Department
open access

An Investigation of the Ranger V-770-8 Engine Installation for the Edo XOSE-1 Airplane 2: Aerodynamics

Description: Investigations were made to determine the cowling and cooling characteristics of the Ranger V-770-8 engine installation in an observation seaplane. Final cowl configurations possessed ample engine and oil-cooler pressure drops for cooling in the critical normal-power climb condition with any of the three baffle configurations tested. The indicated critical Mach number of the cowling was found to be 0.70 as determined by the pressure on the lower lip of the inlet.
Date: October 1945
Creator: Dennard, John S. & Nichols, Mark R.
Partner: UNT Libraries Government Documents Department
open access

Effect of Maximum Cruise-Power Operation at Ultra-Lean Mixture and Increased Spark Advance on the Mechanical Condition of Cylinder Components

Description: "A continuous 50-hour test was conducted to determine the effect of maximum cruise-power operation at ultra-lean fuel-air mixture and increased spark advance on the mechanical conditions of cylinder components. The test was conducted on a nine-cylinder air-cooled radial engine at the following conditions:brake horsepower, 750; engine speed, 1900 rpm; brake mean effective pressure, 172 pounds per square inch; fuel-air ratio, 0.052; spark advance, 30 deg B.T.C.; and maximum rear-spark-plug-bushin… more
Date: September 27, 1945
Creator: Harris, Herbert B.; Duffy, Robert T. & Erwin, Robert D., Jr.
Partner: UNT Libraries Government Documents Department
open access

Heat-Transfer Tests of a Steel Cylinder Barrel With Aluminum Fins

Description: Report presenting tests conducted on a steel cylinder barrel with aluminum fins in order to determine the heat-transfer coefficients of the cylinder and the excellence of the bond between the steel barrel and the aluminum fins. Results regarding the heat-transfer tests and physical tests are provided.
Date: August 1939
Creator: Ellerbrock, Herman H., Jr.
Partner: UNT Libraries Government Documents Department
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Operating Stresses in Aircraft-Engine Crankshafts and Connecting Rods 1: Slip-Ring and Bush Combinations for Dynamic-Strain Measurements

Description: "Tests were conducted to develop a slip-ring and brush system that will perform satisfactorily in aircraft-engine, dynamic-strain-measuring applications where resistance-wire strain gages are the means of measuring the strain and to correlate the data obtained from tests in order to provide a basis for predicting the performance of similar slip-ring and brush systems operating under conditions similar to those imposed by these tests." 24 combinations of materials were tested dry and 8 were test… more
Date: March 30, 1945
Creator: Dutee, Francis J.; Phillips, Franklyn W. & Kemp, Richard H.
Partner: UNT Libraries Government Documents Department
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Operating stresses in aircraft-engine crankshafts and connecting rods 2: instrumentation and test results

Description: Report presenting an investigation to develop methods and equipment for the measurement of operating stresses in aircraft-engine crankshafts and connecting rods. The results indicate that the measurement of stresses in connecting rods is feasible. Results regarding stresses in the crankshaft and stresses in the master connecting rod are provided.
Date: August 1945
Creator: Dutee, Francis J.; Phillips, Franklyn W. & Calvert, Howard F.
Partner: UNT Libraries Government Documents Department
open access

A Preliminary Theoretical Study of Helicopter-Blade Flutter Involving Dependence Upon Coning Angle and Pitch Setting

Description: "A preliminary analysis has been made of the conditions of stability of free oscillations of a hinged rotor in hovering flight. The case analyzed is a rotor with hinges allowing freedom in flapping and lagging and having a completely reversible cyclic pitch-control system, so that a twisting moment on a blade moves the control stick without hindrance from spring or friction constraint. The principal results of this study are presented in the form of a stability chart" (p. 1).
Date: July 1946
Creator: Coleman, Robert P.
Partner: UNT Libraries Government Documents Department
open access

High-Speed Photographs of a YR-4B Production Rotor Blade for Simulated Flight Conditions in the Langley Full-Scale Tunnel

Description: Report discussing tests of a Sikorsky YR-4B helicopter, including photography of a rotor blade in forward-flight conditions at several azimuth angles for several tip-speed ratios. Fabric deformation in the form of sagging and bulging was noted. A reversal in the bending curve near the blade tip was also noted, which was hypothesized to come from losses of lift and high centrifugal force.
Date: March 1945
Creator: Dingeldein, Richard C. & Schaefer, Raymond F.
Partner: UNT Libraries Government Documents Department
open access

Heat-Transfer Tests of a Steel Cylinder Barrel With Aluminum Fins of Optimum Proportions

Description: Report presenting testing of a steel cylinder barrel with aluminum fins of the optimum spacing of 0.090 inch. The primary purpose is to determine the excellence of the thermal bonds between the aluminum fins and the aluminum base and between the aluminum base and the steel and to compare the heat transfer of the barrel with that of barrels with a fin space of 0.052 inch.
Date: November 1940
Creator: Ellerbrock, Herman H., Jr. & Mann, Alvin H.
Partner: UNT Libraries Government Documents Department
open access

Heat Transfer Tests of a Steel Cylinder Barrel With Aluminum Fins With Improved Bonding Between Steel Barrel and Aluminum Base

Description: Report presenting testing of a steel cylinder barrel with aluminum fins in order to evaluate the effect of using preformed aluminum fins on a steel barrel or aluminum barrel. Results regarding the heat-transfer tests and physical tests are provided.
Date: July 1940
Creator: Ellerbrock, Herman H., Jr.
Partner: UNT Libraries Government Documents Department
open access

Heat-Transfer Tests of Two Steel Cylinder Barrels With Aluminum Fins Manufactured by Factory Production Method

Description: Report presenting testing of two engine cylinder barrels with aluminum fins. The primary purpose was to determine the heat-transfer coefficients and the excellence of the bonds between the aluminum fins and the aluminum base and between the aluminum base and the steel of the two barrels when manufactured by a large-volume production method.
Date: August 1940
Creator: Ellerbrock, Herman H., Jr.
Partner: UNT Libraries Government Documents Department
open access

Effect of Engine-Operating Variables and Internal Coolants on Spark-Advance Requirements of a Liquid-Cooled Cylinder

Description: "Tests were conducted to determine the effect of engine-operating variables and internal coolants on spark-advance requirements of a single cylinder from a 12-cylinder liquid-cooled engine for maximum take-off power and maximum cruise economy. The effects of fuel-air ratio, engine speed, air flow (charge density), mixture temperature, and internal coolants on peak-power (optimum) spark advance were investigated. In addition, tests were conducted to determine the effect of spark advance on the k… more
Date: May 18, 1945
Creator: Pfender, John F.; Dudugjian, Carl & Lietzke, A. F.
Partner: UNT Libraries Government Documents Department
open access

Single-Cylinder Engine Tests of Porous Chrome-Plated Cylinder Barrels With Special Bore Coatings for Radial Air-Cooled Engines

Description: Report discussing a series of single-cylinder engine tests to determine the effect of special surface coatings in porous chrome-plated cylinder barrels on oil consumption and ring wear. The coating materials were selected for their bearing and lubrication properties and on their applicability to processing. The surface coatings tested were lead overplates, silver overplates, and colloidal graphite base paint.
Date: January 1946
Creator: Johnson, Robert L. & Anderson, Roy I.
Partner: UNT Libraries Government Documents Department
open access

The Effect of Valve Clearance on Knock-Limited Performance and Engine Cooling

Description: Report discussing the effect of valve clearance on valve-lift diagrams, knock-limited performance, and engine cooling. The performance of single-cylinder and multicylinder engines was also compared across these variables.
Date: April 1945
Creator: Cook, Harvey A.; Richard, Paul H. & Brown, Kenneth D.
Partner: UNT Libraries Government Documents Department
open access

Flight Tests of the Sikorsky HNS-1 (Army YR-4B) Helicopter 1: Experimental Data on Level-Flight Performance With Original Rotor Blades

Description: "Results of performance measurements made in level fight with the HNS-1 (Army YR-4B) helicopter are presented. These data include torquemeter measurements of shaft power for both the main rotor and the tail rotor. The power data, in conjunction with full-scale-tunnel date on the lift and drag of the fuselage, are used to calculate the drag-lift ratio for the main rotor" (p. 1).
Date: March 1945
Creator: Gustafson, F. B.
Partner: UNT Libraries Government Documents Department
open access

Laboratory Investigation of Icing in the Carburetor and Supercharger Inlet Elbow of an Aircraft Engine 1: Description of Setup and Testing Technique

Description: Report discussing icing and de-icing of the carburetor and supercharger inlet of typical aircraft engine induction systems. A description of the systems used to control and simulate different conditions is provided.
Date: December 1945
Creator: Mulholland, Donald R.; Rollin, Vern G. & Galvin, Herman B.
Partner: UNT Libraries Government Documents Department
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