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Low-Flow Characteristics of Streams in the Trempealeau-Black River Basin, Wisconsin

Description: From introduction: The purpose of this report is to describe low-flow characteristics of streams in the Trempealeau-Black River basin where streamflow data have been collected and to present equations useful for estimating low-flow characteristics at ungaged sites.
Date: February 1979
Creator: Holmstrom, B. K.
Partner: UNT Libraries Government Documents Department

Design procedure and limited test results for a high solidity, 12-inch transonic impeller with axial discharge

Description: Report presenting an approximate inverse impeller design procedure based on the assumption of axisymmetric, nonviscous flow along with some limited experimental data obtained from a high solidity, 12-inch transonic impeller. The design procedure includes a point-by-point solution of the impeller flow conditions along a series of streamlines in the radial-axial plane. Results regarding the overall performance, impeller flow limits, and blade structural failure are provided.
Date: April 9, 1953
Creator: Wright, Linwood C. & Kovach, Karl
Partner: UNT Libraries Government Documents Department

Aerodynamic and inlet-flow-field characteristics at a free-stream Mach number of 3.0 for airplanes with circular fuselage cross sections and for two engine locations

Description: Report presenting an experimental investigation of several airplane configurations at Mach 3.0 in a continuous flow tunnel. The configurations had circular fuselage cross sections and a sweptback wing and either two nacelles or two side inlets.
Date: March 18, 1958
Creator: Dryer, Murray & Luidens, Roger W.
Partner: UNT Libraries Government Documents Department

Characteristics of flow over inclined bodies of revolution

Description: From Summary: "Experimental force, moment, and center-of-pressure variations for a large number of bodies of revolution have been compared with the calculated characteristics based on the approximate theory developed in NACA-RM-A9I26. The bodies varied in fineness ratio from 4.5 to 21.1, from blunt unboattailed bodies to airship hulls, and the experimental results are given for widely varying Mach number ranges of angle of attack. It is shown that the lift and drag characteristics are fairly accurately predicted by the theory but that the actual center of pressure is more rearward than the theory indicates."
Date: March 5, 1951
Creator: Allen, H. Julian & Perkins, Edward W.
Partner: UNT Libraries Government Documents Department

Experiments on mixed-free-and-forced-convective heat transfer connected with turbulent flow through a short tube

Description: Report presenting experiments conducted to obtain information on heat transfer in turbulent, mixed-free- and -forced-convection flow. The investigation revealed that the total flow regime as characterized by its Reynolds and Grashof numbers can be subdivided into a forced-flow regime, a free-flow regime, and a mixed-free- and -force-convection regime.
Date: July 1953
Creator: Eckert, E. R. G.; Diaguila, Anthony J. & Curren, Arthur N.
Partner: UNT Libraries Government Documents Department

Secondary flows and boundary-layer accumulations in turbine nozzles

Description: An investigation of secondary-flow loss patterns originating in three sets of turbine nozzle blade passages was conducted by means of flow-visualization studies and detailed flow measurements. For all cases, high loss values were measured in the fluid downstream of the corners formed by the suction surfaces of the blades and the shrouds, and these losses were accompanied by discharge-angle deviations from design values. Despite the size of the loss regions and angle gradients, over-all mass-average blade efficiencies were of the order of 0.99 and 0.98 and, therefore, are not a good index of blade performance.
Date: April 30, 1953
Creator: Rohlik, Harold E.; Kofskey, Milton G.; Allen, Hubert W. & Herzig, Howard Z.
Partner: UNT Libraries Government Documents Department

Further experiments on the flow and heat transfer in a heated turbulent air jet

Description: "Measurements have been made of the mean-total-head and mean-temperature fields in a round turbulent jet with various initial temperatures. The results show that the jet spreads more rapidly as its density becomes lower than that of the receiving medium, even when the difference is not sufficiently great to cause dynamic-pressure function. Rough analytical considerations have given the same relative spread. The effective "turbulent Prandtl number" for a section of the fully developed jet was found to be equal to the true (laminar) Prandtl number within the accuracy measurement" (p. 859).
Date: August 18, 1947
Creator: Corrsin, Stanley & Uberoi, Mahinder S.
Partner: UNT Libraries Government Documents Department

Impingement of water droplets on wedges and diamond airfoils at supersonic speeds

Description: "An analytical solution has been obtained for the equations of motion of water droplets impinging on a wedge in a two-dimensional supersonic flow field with a shock wave attached to the wedge. The closed-form solution yields analytical expressions for the equation of the droplet trajectory, the local rate of impingement and the impingement velocity at any point on the wedge surface, and the total rate of impingement. The analytical expressions are utilized to determine the impingement on the forward surfaces of diamond airfoils in supersonic flow fields with attached shock waves" (p. 1).
Date: July 1953
Creator: Serafini, John S.
Partner: UNT Libraries Government Documents Department

Investigation of flow through an intercooler set at various angles to the supply duct

Description: Report presenting an investigation to determine the flow losses that occur as a result of locating the axis of an intercooler at various angles with respect to the supply-duct axis and also to determine the flow pattern throughout the intercooler. The flow losses were found to be small for angles of inclination up to about 70 degrees. The distribution of flow through the intercooler also appeared to be fairly uniform up to about this angle.
Date: April 1942
Creator: Nichols, Mark R.
Partner: UNT Libraries Government Documents Department

Flow and Force Equations for a Body Revolving in a Fluid

Description: A general method for finding the steady flow velocity relative to a body in plane curvilinear motion, whence the pressure is found by Bernoulli's energy principle is described. Integration of the pressure supplies basic formulas for the zonal forces and moments on the revolving body. The application of the steady flow method for calculating the velocity and pressure at all points of the flow inside and outside an ellipsoid and some of its limiting forms is presented and graphs those quantities for the latter forms.
Date: December 1979
Creator: Zahm, A. F.
Partner: UNT Libraries Government Documents Department

A theory for stability and buzz pulsation amplitude in ram jets and an experimental investigation including scale effects

Description: From Summary: "From a theory developed on a quasi-one-dimensional-flow basis, it was found that the stability of the ram jet is dependent upon the instantaneous values of mass flow and total pressure recovery of the supersonic diffuser and immediate neighboring subsonic diffuser. Conditions for stable and unstable flow were presented. The theory developed in the report was in agreement with the experimental data of the reports both of Sterbentz and Evvard and of Ferri and Nucci."
Date: October 15, 1953
Creator: Trimpi, Robert L.
Partner: UNT Libraries Government Documents Department

Correction of the lifting-line theory for the effect of the chord

Description: "It is shown that a simple correction for the chord of a finite wing can be deduced from the three-dimensional potential flow around an elliptic plate. When this flow is compared with the flow around a section of an endless plate, it is found that the edge velocity is reduced by the factor 1/E, where E is the ratio of the semiperimeter to the span. Applying this correction to the circulation brings the theoretical lift into closer agreement with experiments" (p. 1).
Date: July 1941
Creator: Jones, Robert T.
Partner: UNT Libraries Government Documents Department

A graphical method of determining pressure distribution in two-dimensional flow

Description: By a generalization of the Joukowski method, a procedure is developed for effecting localized modifications of airfoil shapes and for determining graphically the resultant changes in the pressure distribution. The application of the procedure to the determination of the pressure distribution over airfoils of original design is demonstrated. Formulas for the lift, the moment, and the aerodynamic center are also given.
Date: November 12, 1940
Creator: Jones, Robert T. & Cohen, Doris
Partner: UNT Libraries Government Documents Department

Preliminary analysis of axial-flow compressors having supersonic velocity at the entrance of the stator

Description: Report presenting a supersonic compressor design with supersonic velocity at the entrance of the stator on the assumption of two-dimensional flow. The rotor and stator losses assumed in the analysis are based on the results of preliminary supersonic cascade tests. The starting conditions and stability of the flow in rotor and stator are discussed, and the desirability of the variable-geometry stators and adjustable guide vanes is indicated.
Date: September 12, 1949
Creator: Ferri, Antonio
Partner: UNT Libraries Government Documents Department

Observations in flight of the region of stalled flow over the blades of an autogiro rotor

Description: From Summary: "The flow over the inner halves of the rotor blades on a Kellet YG-1B autogiro was investigated in flight by making camera records of the motion of silk streamers attached to the upper surfaces of the blades. These records were analyzed to determine the boundaries of the region within which the flow over the blade sections was stalled for various tip-speed ratios. For the sake of comparison, corresponding theoretical boundaries were obtained. Both the size of the stalled area and its rate of growth with increasing tip-speed ratio were found to be larger than the theory predicted, although experiment agreed with theory with regard to shape and general location of the stalled area."
Date: December 1939
Creator: Bailey, F. J., Jr. & Gustafon, F. B.
Partner: UNT Libraries Government Documents Department

Theories of flow similitude

Description: The laws of comparison of dynamically similar fluid motions are derived by three different methods based on the same principle and yielding the same or equivalent formulas. This report outlines the three current methods of comparing dynamically similar motions, more especially of fluids, initiated respectively by Newton, Stokes (or Helmholtz), and Rayleigh. These three methods, viz., the integral, the differential, and the dimensional, are enough alike to be studied profitably together. They are treated in succession then compared. (author).
Date: May 7, 1928
Creator: Zahm, A. F.
Partner: UNT Libraries Government Documents Department

Drag measurements of two thin wing sections at different index values

Description: It is stated that the index value 6000, as found in normal tests of wing sections with a 20 cm chord, falls in the same region where the transition of laminar to turbulent flow takes place on thin flat plates. It is to be expected that slightly cambered, thin wing sections will behave similarly. The following test of two such wing sections were made for the purpose of verifying this supposition.
Date: June 1927
Creator: Ackeret, J.
Partner: UNT Libraries Government Documents Department

Experiments on transonic flow around wedges

Description: Report presenting a study of several aspects of transonic flow around the forward portions of wedge profiles by means of interferometry. Measurements were made of the two kinds of flow pattern that occur at the leading edge of a wedge at an angle of attack. Results regarding the flow at leading edge, flow around the corner, method of characteristics, drag coefficient of the wedge at 14.5 degree semiangle, and conditions at bases of shock waves are provided.
Date: November 1952
Creator: Wood, George P.
Partner: UNT Libraries Government Documents Department

The Influence of the Diameter Ratio on the Characteristics Diagram of the Axial Compressor

Description: With the further development of axial blowers into highly loaded flow machines, the influence of the diameter ratio upon air output and efficiency gains in significance. Clarification of this matter is important for single-stage axial compressors, and is of still greater importance for multistage ones, and particularly for aircraft power plants. Tests with a single-stage axial blower gave a decrease in the attainable maximum pressure coefficient and optimum efficiency as the diameter ratio increased. The decrease must be ascribed chiefly to the guide surface of the hub and housing between the blades increasing with the diameter ratio.
Date: April 1948
Creator: Eckert, B.; Pflüger, F. & Weinig, F.
Partner: UNT Libraries Government Documents Department

Two-dimensional transonic investigation of flows and forces on a 9-percent-thick airfoil with 30-percent-chord flap

Description: Report presenting an investigation to measure the pressures on and observe by schileren photography the flow about an NACA 65A009 airfoil with a 30-percent-chord trailing-edge flap in transonic flow. The results indicate that the flows over the flap are subject to changes from subsonic to supersonic values, which are dependent on combinations and variations in Mach number, angle of attack, and flap deflection.
Date: February 19, 1957
Creator: Lindsey, Walter F. & Pitts, Robert G.
Partner: UNT Libraries Government Documents Department

An analysis of once-per-revolution oscillating aerodynamic thrust loads on single-rotation propellers on tractor airplanes at zero yaw

Description: A simplified procedure is shown for calculating the once-per-revolution oscillating aerodynamic thrust loads on propellers of tractor airplanes at zero yaw. The only flow field information required for the application of the procedure is a knowledge of the upflow angles at the horizontal center line of the propeller disk. Methods are presented whereby these angles may be computed without recourse to experimental survey of the flow field. The loads computed by the simplified procedure are compared with those computed by a more rigorous method and the procedure is applied to several airplane configurations which are believed typical of current designs. The results are generally satisfactory.
Date: March 21, 1955
Creator: Rogallo, Vernon L.; Yaggy, Paul F. & McCloud, John L., III
Partner: UNT Libraries Government Documents Department

Investigation of unsteady flow past four NACA 6-percent-thick airfoil sections

Description: Report presenting an investigation of the intensity of root-mean-square pressure pulsations and root-mean-square normal-force-coefficient fluctuations conducted on two high-lift airfoils and two 6-series airfoils. Results regarding the factors affecting comparison of data from various test facilities, root-mean-square pressure pulsations, and root-mean-square force fluctuations are provided.
Date: July 26, 1956
Creator: Lindsey, Walter F. & Ladson, Charles L.
Partner: UNT Libraries Government Documents Department

Intermittent-flow coefficients of a poppet valve

Description: "Flow coefficients were determined for the inlet valve of a modern air-cooled cylinder during operation of the valve. The cylinder head with valves was mounted on a large tank that could be evacuated. Operating the valve with a rotating cam allowed air to flow through the valve into the evacuated tank. The change of pressure in the tank was a measure of the amount of air flowing though the valve in a given number of cycles. The flow coefficients were determined from the pressure across the valve, the quantity of air flowing, and the valve-lift curve" (p. 1).
Date: April 1939
Creator: Waldron, C. D.
Partner: UNT Libraries Government Documents Department