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Principles involved in the cooling of a finned and baffled cylinder

Description: An analysis of the cooling problems for a finned cylinder is made on the basis of the known fundamental principles of heat transfer from pipes. Experimental results that support the analysis are presented. The results of previous investigations on the problem are evaluated on the basis of the analysis and the results. An illustration of the application of these principles to a specific problem is included.
Date: June 1938
Creator: Brevoort, M. J.
Partner: UNT Libraries Government Documents Department

Effect of nozzle secondary flows on turbine performance as indicated by exit surveys of a rotor

Description: Report presenting detailed circumferential and radial surveys of total pressure and total temperature made downstream of the turbine rotor of a high-speed, high-specific-mass-flow turbine at design operating conditions. The purpose of this testing was to determine the sources and magnitudes of losses in turbines. Results regarding total pressure ratio, total-temperature-drop ratio, contours of efficiency, and location of the losses are provided.
Date: April 5, 1954
Creator: Whitney, Warren J.; Buckner, Howard A., Jr. & Monroe, Daniel E.
Partner: UNT Libraries Government Documents Department

Intercooler cooling-air weight flow and pressure drop for minimum drag loss

Description: Report presenting an analysis of the power losses in airplane flight of cross-flow plate and tubular intercoolers to determine the cooling-air weight flow and pressure drop that give minimum total power loss for any given cooling effectiveness. The investigation covers a range of flight conditions of altitude, airspeed, lift-drag ratio, supercharger-pressure ratio, and adiabatic efficiency.
Date: April 1944
Creator: Reuter, J. George & Valerino, Michael F.
Partner: UNT Libraries Government Documents Department

Pressure losses of titanium and magnesium slurries in pipes and pipeline transitions

Description: Report presenting comparisons of experimental and calculated pressure losses for Newtonian non-Newtonian materials. The transition loss coefficients obtained for the Newtonian and non-Newtonian materials and those reported in the literature for Newtonian fluids agree within the errors of experiment.
Date: January 1957
Creator: Weltmann, Ruth N. & Keller, Thomas A.
Partner: UNT Libraries Government Documents Department

An evaluation of non-Newtonian flow in pipe lines

Description: Report presenting an analysis of a method for determining pressure losses due to the flow of non-Newtonian materials in pipe lines by using basic flow data obtained from measurements of flow curves, which are rate-of-shear-shear-stress curves. Reported flow and pressure data are analyzed. The validity of the generalized friction diagram for describing flow of Bingham plastics in pipe lines is shown by an evaluation of experimental data of two independent investigators.
Date: February 1955
Creator: Weltmann, Ruth N.
Partner: UNT Libraries Government Documents Department

Correlation of turbine-blade-element losses based on wake momentum thickness with diffusion parameter for a series of subsonic turbine blades in two-dimensional cascade and for four transonic turbine rotors

Description: Report presenting an analysis of losses occurring in a series of subsonic turbine blades in a low-speed two-dimensional cascade and in a related series of four transonic rotors. Results regarding the two-dimensional cascade loss correlations, transonic turbine loss correlations, effect of unsteady flows, and mixing of stator wakes are provided.
Date: April 21, 1955
Creator: Wong, Robert Y. & Stewart, Warner L.
Partner: UNT Libraries Government Documents Department

Wind-tunnel tests of four- and six-blade single- and dual-rotating tractor propellers

Description: Test of 10-foot diameter, four and six blade single-rotating and dual-rotating propellers were conducted in the NACA propeller-research tunnel. The propellers were mounted at the front end of a streamline body incorporating spinners to house the hub portions. The effect of a symmetrical wing mounted in the slipstream ranged from 20 degrees to 65 degrees setting corresponds to airplane speeds greater than 500 miles per hour. The results indicate that dual-rotating propellers were from 0 to 6 percent more efficient than single-rotating ones; but, when the propellers operated in the presence of a wing, the gain was reduced by about one-half. Other advantages of dual-rotating propellers were found to include greater power absorption and greater efficiency at the low V/nD operating range of high-pitch propellers.
Date: 1942
Creator: Biermann, David & Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department

Approximate effect of leading-edge thickness, incidence angle, and inlet mach number on inlet losses for high-solidity cascades of low cambered blades

Description: Report presenting an approximate, theoretical analysis of the inlet or induction losses due to subsonic flow into a high-solidity cascade of finite thickness blades at incidence angle. Results indicated that the losses can become considerable for large deviations from the design incidence such as compressor off-design operating conditions. Results regarding the computational results, significance of assumptions and limitations, comparison of theoretical approximation with actual compressor results, and applicability of the results are provided.
Date: December 1954
Creator: Wright, Linwood C.
Partner: UNT Libraries Government Documents Department

Prediction of losses induced by angle of attack in cascades of sharp-nosed blades for incompressible and subsonic compressible flow

Description: Report presenting a method of computing the losses in total pressure caused by a non-zero angle of attack at the inlet to a row of sharp-nosed blades for both incompressible and subsonic compressible flow. The method is based on momentum considerations across a row of zero-thickness flat plates and assumes that the blade force is normal to the plate surface.
Date: January 1955
Creator: Kramer, James J. & Stanitz, John D.
Partner: UNT Libraries Government Documents Department

Flow-turning losses associated with zero-drag external-compression supersonic inlets

Description: Note presenting an analysis based on momentum and continuity considerations in order to evaluate the total-pressure recovery of zero-wave-drag external-compression supersonic air inlets for a range of Mach numbers. The geometry of the inlets can cause a significant loss in inlet total-pressure recovery that arises in the process of turning the flow back to the axial direction after supersonic compression.
Date: October 1957
Creator: Meyer, Rudolph C.
Partner: UNT Libraries Government Documents Department

TRANSMISSION-LINE MISSILE ANTENNAS

Description: Protruding rocket antennas of low silhouette are examined using transmission-line concepts. The theory was developed specifically for nondissipative terminations and line sections; however, the formulas are readily generalized to include ohmic losses in the lines and terminations. Adaptive computations may be made for conductors other than circular and the theory may be used to analyze antennas of other missiles. (J.R.D.)
Date: November 20, 1958
Creator: King, R.W.P.; Harrison, C.W. Jr. & Denton, D.H. Jr.
Partner: UNT Libraries Government Documents Department

Effect of reduced stator-blade trailing-edge thickness on over-all performance of a transonic turbine

Description: A transonic turbine with a stator trailing-edge thickness reduced from 0.030 to 0.010 inch has been investigated experimentally. The performance results indicated an increase in efficiency of 0.6 of a point at design operation, and as much as 2.4 points at off-design conditions, as a result of reducing the trailing-edge thickness. This improvement could only be partially accounted for by the theoretical change in mixing loss for the two stator-blade rows, and it was felt that the improvement was largely due to a reduced amount of low-velocity fluids entering the rotor and the interference effect of these fluids whth the mainstream flow.
Date: November 1, 1955
Creator: Whitney, Warren J.; Stewart, Warner L. & Wong, Robert Y.
Partner: UNT Libraries Government Documents Department

Losses of Vitamin C Content During the Cooking of Summer Squash

Description: The general food supply is usually the source of vitamin C for many people, and since squash is a common food in the popular diets of Texans and is so generally grown over the state, this study has a two-fold purpose: (1) to ascertain the amount of vitamin C in the two varieties of squash most commonly used as food in Texas, and (2) to determine the effect of various methods of cooking upon the vitamin C content of these two varieties of squash.
Date: 1941
Creator: Woodruff, Reba N.
Partner: UNT Libraries

Icing Characteristics and Anti-Icing Heat Requirements for Hollow and Ternally Modified Gas-Heated Inlet Guide Vanes

Description: "A two-dimensional inlet-guide-vane cascade was investigated to determine the effects of ice formations on the pressure losses across the guide vanes and to evaluate the heated gas flow and temperature required to prevent Icing at various conditions. A gas flow of approximately 0.4 percent of the inlet-air flow was necessary for anti-icing a hollow guide-vane stage at an inlet-gas temperature of 500 F under the following icing conditions: air velocity, 280 miles per hour; water content, 0.9 gram per cubic meter; and Inlet-air static temperature, 00 F. Also presented are the anti-icing gas flows required with modifications of the hollow Internal gas passage, which show heat input savings greater than 50 percent" (p. 1).
Date: December 5, 1950
Creator: Gray, Vernon H. & Bowden, Dean T.
Partner: UNT Libraries Government Documents Department

Investigation of the pressure-loss characteristics of a turbojet inlet screen

Description: Report presenting the results of an investigation to determine the static-pressure losses and total-pressure distributions of a turbojet inlet screen. The screen was tested in two configurations: one with the vane leading edges square and rough and the other with the vane leading edges rounded. Results regarding the static-pressure-loss coefficient, corrected static-pressure loss, and total-pressure distributions are provided.
Date: September 1947
Creator: Lankford, John L.
Partner: UNT Libraries Government Documents Department

Comparison of pressure-loss characteristics of several tail-cone air-induction systems for air-cooled gas-turbine rotors

Description: Report presenting testing of three scale models and a full-scale configuration of systems for ducting cooling air through a turbojet engine tail cone to a cooled turbine rotor in order to determine pressure-loss characteristics.
Date: January 12, 1953
Creator: Smith, Gordon T. & Curren, Arthur N.
Partner: UNT Libraries Government Documents Department

Dynamics of beam halo in mismatched beams

Description: High-power proton linacs for nuclear materials transmutation and production, and new accelerator-driven neutron spallation sources must be designed to control beam-halo formation, which leads to beam loss. The study of particle-core models is leading to a better understanding of the causes and characteristics of beam halo produced by space-charge forces in rms mismatched beams. Detailed studies of the models have resulted in predictions of the dependence of the maximum amplitude of halo particles on a mismatch parameter and on the space-charge tune-depression ratio. Scaling formulas have been derived which will provide guidance for choosing the aperture radius to contain the halo without loss.
Date: September 1, 1996
Creator: Wangler, T.P.; Garnett, R.W.; Gray, E.R.; Ryne, R.D. & Wang, T.S.
Partner: UNT Libraries Government Documents Department

Description of a spectral atmospheric radiation monitoring network

Description: A modest network of four radiometers is described which will be used to make spectral infrared atmospheric emission measurements on a continuous basis starting in the summer of 1978. A commercial infrared radiometer (Barnes model 12-880) forms the basis of the field instrument package. This radiometer is equipped with an eight position filter wheel, an external chopper, and a pyroelectric detector. The detector and filter wheel are located in a cavity behind a germanium lens, which has a 2/sup 0/ field of view, and the cavity is maintained at a reference temperature of 45/sup 0/C.
Date: June 1, 1978
Creator: Martin, M. & Berdahl, P.
Partner: UNT Libraries Government Documents Department

Calculation of wake power losses in a two-level array: a simple case study

Description: One method of adding capacity is to install another array of turbines whose hub height is above the existing array. This report estimates the wake interference that could be expected in a two-level array. Interference is estimated for a typical situation that may be encountered by a wind farm developer. A modified Lissaman array model is used to make the wake interference calculations. The model calculations show that the wake interference between the two levels is small for the turbine characteristics and turbine layouts considered. (The windwise spacings are about 5.4 and 10.8D for the lower and upper levels of turbines, respectively.) Power losses are about 5% or less at rated speed. Thus, two-level arrays may be a viable way of increasing the generating capacity of existing wind farms.
Date: December 1, 1985
Creator: Barnard, J.C.
Partner: UNT Libraries Government Documents Department

As-operated heat loss coefficients of residential buildings in the Pacific Northwest: An analysis of empirical space-heating energy data

Description: Previous research of residential electrical space-heating data has revealed that the heat loss coefficients obtained from empirical data ( as-operated'' UAs) are, on average, about 25% below the UA calculated from the shell construction of each building. This as-operated UA is obtained from a linear regression of the measured space-heating energy consumption versus the inside-outside temperature difference. This finding indicates that simple steady-state calculation techniques for heating energy consumption utilizing only UAs may be inaccurate in estimating annual consumption. The purpose of this research was to study how climate, construction, and occupant variables may affect the as-operated UA and, therefore, the annual heating energy consumption. Specifically, the goal is to gain a greater understanding of how and why the as-operated UA differs from the construction-based nameplate UA. Multiple seasons of daily heating data from 131 occupied single-family residential sues were analyzed. A multiple linear regression was used to generate a model that utilizes the construction-based UAs and other characteristics of individual residences to predict an as-operated UA that better estimates annual heating energy.
Date: January 1, 1992
Creator: Lucas, R.G. & Pratt, R.G.
Partner: UNT Libraries Government Documents Department