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Dynamic Determination of the Compressibility of Metals

Description: Abstract: "Equation of State data for duralumin in the pressure range from 0.1 to 0.3 megabar have been determined dynamically by measuring shock and free surface velocity electrically in a place of 24 ST duralumin which has been stressed by a high explosive donation. The theory is presented which allows comparison with data obtained by other experimenters, requiring the relationship between pressure and compression either at constant entropy or constant temperature. The empirical form chosen for the equation of state p = αμ + βμ-2 expresses the pressure as a quadratic function of the compression. Experimental techniques are described in detail. Five points are given for equation of state of duralumin in the pressure range from approximately 0.15 megabar to 0.33 megabars. Some data are also presented for cadmium and steel."
Date: 1954
Creator: Goranson, Roy W.; Bancroft, Dennison; Burton, Blendin L.; Blechar, Theodore; Houston, Edwin E.; Gittings, Elisabeth F. et al.
Partner: UNT Libraries Government Documents Department

Charts of Compressibility Factors and Charts Showing Quantities Delivered by Commercial Cylinders for Hydrogen, Nitrogen, and Oxygen

Description: Two charts are given for each of the gases hydrogen, nitrogen, and oxygen. The first gives directly the number of standard cubic feet of the gas which a cylinder will deliver. The second chart gives values of the compressibility factor and of the density.
Date: November 17, 1948
Creator: Hoge, Harold J.; Meyers, Cyril H. & McCoskey, Robert E.
Partner: UNT Libraries Government Documents Department

Effect of Compressibility at High Subsonic Velocities on the Lifting Force Acting on an Elliptic Cylinder

Description: An extended form of the Ackeret iteration method, applicable to arbitrary profiles, is utilized to calculate the compressible flow at high subsonic velocities past an elliptic cylinder. The angle of attack to the direction of the undisturbed stream is small and the circulation is fixed by the Kutta condition at the trailing end of the major axis. The expression for the lifting force on the elliptic cylinder is derived and shows a first-step improvement of the Prandtl-Glauert rule. It is further shown that the expression for the lifting force, although derived specifically for an elliptic cylinder, may be extended to arbitrary symmetrical profiles.
Date: May 16, 1946
Creator: Kaplan, Carl
Partner: UNT Libraries Government Documents Department

Tests of Airfoils Designed to Delay the Compressibility Burble

Description: "Fundamental investigations of compressibility phenomena for airfoils have shown that serious adverse changes of aerodynamic characteristics occur as the local speed over the surface exceeds the local speed of sound. These adverse changes have been delayed to higher free-stream speeds by development of suitable airfoil shapes. The method of deriving such airfoil shapes is described, and aerodynamic data for a wide range of Mach numbers obtained from tests of these airfoils in the Langley 24-inch high-speed tunnel are presented" (p. 1).
Date: 1943
Creator: Stack, John
Partner: UNT Libraries Government Documents Department

Tests of Airfoils Designed to Delay the Compressibility Burble

Description: Note presenting a method of deriving certain airfoil shapes that delay certain compressibility phenomena, and the aerodynamic data for a wide range of Mach numbers obtained from tests of the airfoils in the 24-inch high-speed tunnel. The airfoils, which are designated the NACA 16-series, have increased critical Mach number. Results regarding the airfoil comparison, critical speed, minimum drag, and use of the data are provided.
Date: December 1944
Creator: Stack, John
Partner: UNT Libraries Government Documents Department

Preliminary Correlation of the Effect of Compressibility on the Location of the Section Aerodynamic Center at Subcritical Speeds

Description: Memorandum presenting a correlation of available two-dimensional airfoil data to determine the effects of compressibility on the location of the section aerodynamic center at low lift coefficients. The results indicate that large forward or rearward movements of the aerodynamic center with Mach number are possible.
Date: November 3, 1948
Creator: Polhamus, Edward C.
Partner: UNT Libraries Government Documents Department

Note on Compressibility Effects on Downwash at the Tail at Subcritical Speeds

Description: "Calculations have been made to show the magnitude of the compressibility effects on the downwash at the tail at subcritical speeds. Experimental results of tests of two airplane models are included to give some verification of the theory. The calculations showed that the effects of compressibility on the span load distribution along the wing and on the downwash angle at the tail are small for constant values of the lift coefficient. The experimental results confirmed these calculations" (p. 1).
Date: March 1945
Creator: Nielsen, Jack N. & Sweberg, Harold H.
Partner: UNT Libraries Government Documents Department

Effect of Compressibility on Normal-Force, Pressure, and Load Characteristics of a Tapered Wing of NACA 66-Series Airfoil Sections With Split Flaps

Description: Note presenting a high-speed wind tunnel investigation of a tapered wing of NACA 66-series airfoil sections equipped with split flaps conducted at Mach numbers up to 0.585 to determine the effects of compressibility on the normal-force, pressure, and load characteristics. Results regarding normal-force characteristics, span-load distribution, pitching-moment characteristics, and flap normal-force and hinge-moment coefficients are provided.
Date: December 1948
Creator: West, F. E., Jr. & Hallissy, J. M., Jr.
Partner: UNT Libraries Government Documents Department

The Compressibility Burble

Description: "Simultaneous air-flow photographs and pressure-distribution measurements have been made of the NACA 4412 airfoil at high speeds in order to determine the physical nature of the compressibility bubble. The flow photographs were obtained by the Schlieren method and the pressures were simultaneously measured for 54 stations on the 5-inch-chord wing by means of a multiple-tube photographic manometer. Pressure-measurement results and typical Schlieren photographs are presented" (p. 1).
Date: October 1935
Creator: Stack, John
Partner: UNT Libraries Government Documents Department

A comparison of the experimental subsonic pressure distributions about several bodies of revolution with pressure distributions computed by means of the linearized theory

Description: "An analysis is made of the effects of compressibility on the pressure coefficients about several bodies of revolution by comparing experimentally determined pressure coefficients with corresponding pressure coefficients calculated by the use of the linearized equations of compressible flow. The results show that the theoretical methods predict the subsonic pressure-coefficient changes over the central part of the body but do not predict the pressure-coefficient changes near the nose. Extrapolation of the linearized subsonic theory into the mixed subsonic-supersonic flow region fails to predict a rearward movement of the negative pressure-coefficient peak which occurs after the critical stream Mach number has been attained" (p. 1125).
Date: November 5, 1951
Creator: Matthews, Clarence W.
Partner: UNT Libraries Government Documents Department

Observations of compressibility phenomena in flight

Description: Report presenting compressibility phenomena under flight conditions on the XF2A-2 airplane, which was subjected to a series of dives and pull-outs at speeds up to 550 miles per hour corresponding to Mach numbers of 0.74. Results regarding time histories, pressure data, drag coefficient, and elevator control force are provided.
Date: April 1943
Creator: Rhode, Richard V. & Pearson, H. A.
Partner: UNT Libraries Government Documents Department

Low tip Mach number stall characteristics and high tip Mach number compressibility effects on a helicopter rotor having an NACA 0009 tip airfoil section

Description: Report presenting an investigation conducted on the helicopter test tower to determine experimentally the low tip Mach number stall and high tip Mach number drag divergence characteristics of a helicopter rotor with an NACA 0009 tip airfoil section. Results regarding rotor hovering performance, rotor-blade pitching moments, rotor profile-drag torque, and a comparison with two-dimensional drag-divergence data are provided.
Date: July 1958
Creator: Powell, Robert D., Jr. & Carpenter, Paul J.
Partner: UNT Libraries Government Documents Department

Comparison with experiment of several methods of predicting the lift of wings in subsonic compressible flow

Description: Report presenting several methods of predicing the lift of wings in subsonic compressible flow as compared with experimental results. Semiempirical formulas for predicting the subsonic effects of compressibility on the lift of wings were developed. Both experiments and calculations indicated a decrease in the variation of lift with Mach number for increasing sweep.
Date: October 1948
Creator: Murray, Harry E.
Partner: UNT Libraries Government Documents Department

The effect of thickness ratio on section thrust distribution as determined from a study of wake surveys of the NACA 4-(0)(03)-045 and 4-(0)(08)-045 two-blade propellers up to forward Mach numbers of 0.925

Description: Report presenting testing of two two-blade propellers in the 8-foot high-speed tunnel for a range of blade angles and Mach numbers. The results show that changes in thrust loading due to compressibility effects were much smaller for the thin-blade propeller than for the thick-blade propeller.
Date: April 5, 1951
Creator: Harrison, Daniel E. & Milillo, Joseph R.
Partner: UNT Libraries Government Documents Department

Comparison of various methods for computing drag from wake surveys

Description: "The various equations for computing profile drag by the momentum method are examined, and the errors arising from complete or partial neglect of compressibility effects in the Jones equation and the Bicknell equation are evaluated. The integrating method of Silverstein and Katzoff is shown to be accurate over a wide range of Mach number and wake shapes" (p. 1).
Date: January 1943
Creator: Davis, Wallace F.
Partner: UNT Libraries Government Documents Department

Analysis of two-dimensional compressible-flow loss characteristics downstream of turbomachine blade rows in terms of basic boundary-layer characteristics

Description: Report presenting the effect of compressibility on the loss characteristics downstream of two-dimensional turbomachine blade rows. In this particular example, increasing the trailing-edge thickness increased the overall loss coefficients significantly, with an effect of compressibility only at exit flow angles close to axial.
Date: July 1955
Creator: Stewart, Warner L.
Partner: UNT Libraries Government Documents Department

Estimation of Critical Speeds of Airfoils and Streamline Bodies

Description: Report presenting methods and charts for estimating the critical compressibility speeds of a large number of airfoils and streamline bodies. The systematic effects of thickness, thickness distribution, camber, camber location, leading-edge radius, and lift coefficient are considered. The results indicate that with a given lift coefficient, the thickness of the airfoil or of the body is the primary factor controlling its critical speed.
Date: March 1940
Creator: Robinson, Russell G. & Wright, Ray H.
Partner: UNT Libraries Government Documents Department

Flight Measurements of Compressibility Effects on a Three-Blade Thin Clark Y Propeller Operating at Constant Advance-Diameter Ratio and Blade Angle

Description: Report presenting flight tests of a three-blade thin Clark Y propeller operating at a fixed blade angle of approximately 46.8 degrees at 0.75 radius, at an advance-diameter ratio of 2.37, and at true airplane speeds of approximately 300 and 450 miles per hour. Comparisons of the results at the two different speeds indicated losses in propeller efficiency from 11 to 18 percent at high speed. Report is incomplete.
Date: July 1943
Creator: Vogeley, A. W.
Partner: UNT Libraries Government Documents Department

Plane and Three-Dimensional Flow at High Subsonic Speeds

Description: "For two- and three-dimensional flow in a compressible medium, a simple relation is given by which, to a first approximation, the quantitative influence of compressibility upon the velocities and pressures can be understood in a clear manner. In the application of this relation the distinct behaviors of two-dimensional and axially symmetric three-dimensional flow with increasing Mach number are brought out. For slender elliptic cylinders and ellipsoids of revolution, calculations are made of the critical Mach number; that is, the Mach number at which local sonic velocity is achieved on the body" (p. 1).
Date: October 1946
Creator: Göthert, B.
Partner: UNT Libraries Government Documents Department

Compressibilities of gases

Description: Reproduction of thirteen graphs for computing compressibilities of various gases and for computing the volumes delivered from cylinders containing various gases.
Date: November 21, 1925
Creator: Pickering, Samuel Fisher
Partner: UNT Libraries Government Documents Department

Expressions for Measuring the Accuracy of Approximate Solutions to Compressible Flow Through Cascades of Blades With Examples of Use

Description: Report presenting four necessary conditions for steady irrotational compressible flow through a straight cascade of blades as derived from the irrotationality condition and conservation of mass and momentum. The expressions used can only give an approximate solution to the conditions, as there are an infinite number of them.
Date: October 1951
Creator: Sinnette, John T., Jr.; Costello, George R. & Cummings, Robert L.
Partner: UNT Libraries Government Documents Department

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.
Partner: UNT Libraries Government Documents Department

Analysis of Heat and Compressibility Effects in Internal Flow Systems and High-Speed Tests of a Ram-Jet System

Description: Report presenting an analysis of the effects of heat and compressibility in the flow through the internal systems of aircraft. Equations and charts are developed whereby the flow characteristics at key stations in a typical internal system may be readily obtained.
Date: September 1942
Creator: Becker, John V. & Baals, Donald D.
Partner: UNT Libraries Government Documents Department

Effect of Compressibility on the Pressure and Forces Acting on a Modified NACA 65,3-019 Airfoil Having a 0.20-Chord Flap

Description: "An investigation has been conducted in the Langley rectangular high-speed tunnel to determine the effect of compressibility on the pressure distribution for a modified NACA 65,3-019 airfoil having a 0.20-chord flap. The investigation was made for an angle-of-attack range extending from -2 to 12 deg at .20 flap deflections from 0 to -12 deg. Test data were obtained for Mach numbers from 0.28 to approximately 0.74" (p. 1).
Date: January 1946
Creator: Lindsey, W. F.
Partner: UNT Libraries Government Documents Department