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open access

Addition of Heat to a Compressible Fluid in Motion

Description: From Introduction: "The purpose of this report is to summarize, without extended proofs, the results of a study of a simplified model of nonadiabiatic, compressible fluid flow, both subsonic and supersonic, and to state these results in a form that will make them immediately useful in providing a theoretical background for current technical problems of high-speed combustion.
Date: February 1945
Creator: Hicks, Bruce L.
open access

Aerodynamic Characteristics of Four NACA Airfoil Sections Designed for Helicopter Rotor Blades

Description: "The purpose of the present work is to extend the previous investigation and to derive additional airfoil sections designed to minimize the undesirable characteristics of the previously tested airfoils. The tests of these additional airfoils were made in the Langley two-dimensional low-turbulence tunnel (LTT)" (p. 2).
Date: February 1946
Creator: Stivers, Louis S., Jr. & Rice, Fred J., Jr.
open access

Altitude-wind-tunnel tests of power-plant installation in jet-propelled fighter

Description: From Introduction: "The research program included clean-up tests (unpublished data) and stability and control tests (reference 1) made in the NACA Langley full-scale tunnel. An investigation of the aerodynamic characteristics of the power-plant installation in the Cleveland altitude wind tunnel is discussed in this report."
Date: February 1946
Creator: Preston, G. Merritt; Black, Fred O., Jr. & Jagger, James M.
open access

An Analysis of Jet-Propulsion Systems Making Direct Use of the Working Substance of a Thermodynamic Cycle

Description: From Summary: "The results of the analysis showed that the combined efficiency, which is unacceptably low at speeds less than 300 miles per hour, becomes nearly equal to that of conventional power plants of current design at 500 miles per hour. It was also shown that the efficiency will be increased considerably as the physical limitations on cycle temperature and blower speed are raised and as the efficiencies of the system components are improved."
Date: February 1945
Creator: Rubert, Kennedy F.
open access

An analysis of the fatigue life of an airplane wing structure under overload conditions

Description: From Introduction: "Fatigue life expectancy in normal transport operations was investigated in reference 1 and was found to be of equal importance with single-gust life. The effect of overload operation of transport airplanes on the probability of encountering single critical gusts was investigated in reference 2 and the frequency of critical gusts was found to increase rapidly with overload. The effect of overload operation on fatigue strength, however, has not heretofore been evaluated, hence… more
Date: February 1946
Creator: Putnam, Abbott A. & Reisert, Thomas D.
open access

The belt method for measuring pressure distribution

Description: "The measurement of pressure distribution may be accomplished rapidly for any number of locations deemed necessary in model or full-scale investigations by use of the 'belt' method. Reasonable accuracy may be obtained by careful use of this method" (p. 1).
Date: February 1943
Creator: Corson, Blake W., Jr.
open access

Calibrations of Service Pitot Tubes in the Langley 24-Inch High-Speed Tunnel

Description: Report discusses calibration testing performed on a Kollsman type G-1 and an NAF No. 1 pitot tube at several Mach numbers and angles of attack. The effect of drain holes on the flow within the pitot tube was analyzed and the ability to estimate the error in the total pressure was created. The accuracy of the extrapolated and estimated values were found to be within reasonable limits.
Date: February 1946
Creator: Lindsey, W. F.
open access

Comparative Tests of the Strength and Tightness of Commercial Flush Rivets of One Type and NACA Flush Rivets in Machine-Countersunk and Counterpunched Joints

Description: Report discusses an investigation that was conducted to compare the strength and tightness of machine-countersunk flush-riveted joints assembled with NACA flush rivets and a type of commercial flush rivet. A comparison was also generated between the strength and tightness of counterpunched flush-riveted joints assembled with the same types of rivet. NACA's flush-riveted joints tended to be stronger and tighter than the commercial joints.
Date: February 1, 1944
Creator: Mandel, Merven W.
open access

Compressive Strength of Flat Panels With Z-Section Stiffeners

Description: Report presenting compression testing on several series of flat panels with Z-section stiffeners with varying relative dimensions. The data presented show the effect of dimension ratio on the buckling stress for the sheet and on average stress at maximum load.
Date: February 1944
Creator: Rossman, Carl A.; Bartone, Leonard M. & Dobrowski, Charles V.
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

A Cooling Correlation of the Wright R-2600-8 Engine Showing the Effect of Water as an Internal Coolant

Description: Report presenting an attempt to establish a correlation of the cooling characteristics of the Wright R-2600-8 engine with water as an internal coolant and to investigate methods of introducing the water. A cooling correlation, including the effect of water as an internal coolant, was established by use of the NACA cooling-correlation method. Results regarding the cooling-performance predictions and engine condition are provided.
Date: February 1945
Creator: Koenig, Robert J. & Engelman, Helmuth W.
open access

Cooling of a Double-Row Radial Engine by Water Injection to the Individual Cylinders

Description: "An injection system that supplies water to each cylinder of a double-row radial engine was tested...as part of a general investigation of the power-plant installation of a four-engine heavy bomber. The tests were conducted to determine the effectiveness of water injection in cooling the engine during take-off. The injection of 500 pounds of water at the take-off power condition reduced the maximum measured exhaust-valve-seat temperature 64 degrees Fahrenheit and the maximum spark-plug-gasket t… more
Date: February 1945
Creator: Monroe, Louis L. & Friedman, Harold E.
open access

Determination of Induced Velocity in Front of an Inclined Propeller by a Magnetic-Analogy Method

Description: Report presenting the horizontal and vertical components of the induced velocity in front of an inclined propeller in a horizontal stream obtained by a magnetic-analogy method. The problem was formulated in terms of the linear theory of the acceleration potential of an incompressible nonviscous fluid.
Date: February 1946
Creator: Gardner, Clifford S. & LaHatte, James A., Jr.
open access

Determination of Jet-Boundary Corrections to Cowling-Flap-Outlet Pressures by an Electrical Analogy Method

Description: Report presenting corrections to the velocities near a cowling-flap tip in order to determine jet-boundary corrections to cowling-flap-outlet pressures. The presence of the low-energy air leaving the flap opening was taken into account by so shaping the nacelle model that its outer surface represented the stream surface leaving the flap tip. Copper was found unsatisfactory for use as electrode material.
Date: February 1944
Creator: Katzoff, S. & Finn, Robert S.
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

Determination of the Effect of Horizontal-Tail Flexibility on Longitudinal Control Characteristics

Description: Report presenting an iteration method for determining the longitudinal control characteristics of a flexible horizontal tail. The method permits factors such as the actual spanwise variation of elasticity and the aerodynamic induction effects due to three-dimensional flow to be accounted for to any degree of accuracy needed. An analysis is also included of the effects of horizontal-tail flexibility on the tail effectiveness, the hinge-moment characteristics, and the control-force gradients in a… more
Date: February 1945
Creator: Harmon, S. M.
open access

Determination of the Stability and Control Characteristics of a Straight-Wing, Tailless Fighter-Airplane Model in the Langley Free-Flight Tunnel

Description: Report presenting an investigation to determine the stability and control characteristics of a straight-wing, tailless fighter model with a pusher propeller in the free-flight tunnel. The investigation consisted principally of force and flight tests of a powered dynamic model. Results regarding longitudinal stability, longitudinal control, trim at high angles of attack, lateral stability, and lateral control are provided.
Date: February 1946
Creator: Seacord, Charles L., Jr. & Ankenbruck, Herman O.
open access

Determination of the Stability and Control Characteristics of a Tailless All-Wing Airplane Model with Sweepback in the Langley Free-Flight Tunnel

Description: Force and flight tests were performance on an all-wing model with windmilling propellers. Tests were conducted with deflected and retracted flaps, with and without auxiliary vertical tail surfaces, and with different centers of gravity and trim coefficients. Results indicate serious reduction of stick-fixed longitudinal stability because of wing-tip stalling at high lift coefficient. Directional stability without vertical tail is undesirably low. Low effective dihedral should be maintained. Ele… more
Date: February 1945
Creator: Campbell, John P. & Seacord, Charles L., Jr.
open access

Development of thermal ice-prevention equipment for the B-24D airplane

Description: Report presenting a thermal ice-prevention system for the B-24D airplane. The report includes a description of the design and an outline of the method of design analysis. Results of performance tests of the installation will be presented in a supplementary report.
Date: February 1943
Creator: Jones, Alun R. & Rodert, Lewis A.
open access

Dilution of Exhaust-Gas Samples From a Multicylinder Engine Equipped With an Exhaust-Gas Collector

Description: Report discusses the results of an investigation to determine the effect of a collector ring on exhaust-gas sampling. The results of tests to determine the percentage by volume of exhaust gas from the collector ring are presented for several engine powers and speeds. The danger of air dilution from the breathing action of the engine is almost entirely eliminated by the use of a collector ring.
Date: February 1945
Creator: Butze, Helmut F.
open access

Effect of changing the stroke on air capacity, power output and detonation of a single-cylinder engine

Description: Report presenting an investigation of a special single-cylinder test engine constructed with provision for operation with three different lengths of piston stroke. Results regarding the air capacity of the engine, extent to which the spark must be retarded in order to prevent detonation, and brake mean effective pressure are provided.
Date: February 1945
Creator: Livengood, James C. & Eppes, James V. D.
open access

The Effect of Compression Ratio on Knock Limits of High-Performance Fuels in a CFR Engine 3: Blends of 2,3-Dimethylpentane With 28-R

Description: Report discussing the knock-limited performance of blends of 2,3-dimethylpentane and 23-R fuel in an F-4 engine at three sets of conditions and three compression ratios. The knock-limited performance of 2,3-dimethylpentane has about the same sensitivity to compression ratio and inlet-air temperature as 28-R fuel.
Date: February 10, 1945
Creator: Alquist, Henry E. & Tower, Leonard K.
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