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Characterization of Open-Cycle Coal-Fired MHD Generators. Quarterly Technical Summary Report No. 2, October 1--December 31, 1976. [Negative Ion Formation, Electron/Slag Interaction, and Alkali/Slag Interaction]

Description: A study on how nonfuel components of coal will affect the electron and alkali seed chemistry in a high temperature coal combustion system like those envisioned for direct fired MHD generators is described. Three specific problems are being considered. The first problem area is to characterize the formation of negative ions due to electron attachment processes in the combustion flow. While some stable negative ions may be formed from hydrocarbon combustion species (OH, HCO/sup -//sub 3/), the bu… more
Date: January 15, 1977
Creator: Kolb, C. E.; Yousefian, V.; Wormhoudt, J.; Martinez-Sanchez, M. & Kerrebrock, J. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Motion of particles in a thermal boundary layer

Description: In the course of using laser Doppler velocimetry to study combustion in a thermal boundary layer, the particle count rate was found to decrease abruptly to zero inside the boundary layer. Experimental and theoretical investigation of this phenomenon was carried out. The motion of the particles may be due to the combined effects of thermophoresis and radiative heating.
Date: June 15, 1978
Creator: Schefer, R.W.; Agrawal, Y.; Cheng, R.K.; Robben, F. & Talbot, L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Boundary Layer Cloudiness Parameterizations Using ARM Observations

Description: This study used DOE ARM data and facilities to: (1) study macroscopic properties of continental stratus clouds at SGP and the factors controlling these properties, (2) develop a scientific basis for understanding the processes responsible for the formation of boundary layer clouds using ARM observations in conjunction with simple parametric models and LES, and (3) evaluate cumulus cloud characteristics retrieved from the MMCR operating at TWP-Nauru. In addition we have used high resolution 94 G… more
Date: September 15, 2004
Creator: Albrecht, Bruce
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Exact solutions of laminar-boundary-layer equations with constant property values for porous wall with variable temperature

Description: From Summary: "Exact solution of the laminar-boundary-layer equations for wedge-type flow with constant property values are presented for transpiration-cooled surfaces with variable wall temperatures. The difference between wall and stream temperature is assumed proportional to a power of the distance from the leading edge. Solutions are given for a Prandtl number of 0.7 and ranges of pressure-gradient, cooling-air-flow, and wall-temperature-gradient parameters. Boundary-layer profiles, dimensi… more
Date: July 15, 1954
Creator: Donoughe, Patrick L. & Livingood, John N. B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Similar Solutions for the Compressible Laminar Boundary Layer with Heat Transfer and Pressure Gradient

Description: "Stewartson's transformation is applied to the laminar compressible boundary-layer equations and the requirement of similarity is introduced, resulting in a set of ordinary nonlinear differential equations previously quoted by Stewartson, but unsolved. The requirements of the system are Prandtl number of 1.0, linear viscosity-temperature relation across the boundary layer, an isothermal surface, and the particular distributions of free-stream velocity consistent with similar solutions. This sys… more
Date: October 15, 1954
Creator: Cohen, Clarence B. & Reshotko, Eli
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Experimental Investigation of Laminar-Boundary-Layer Control on an Airfoil Section Equipped With Suction Slots Located at Discontinuities in the Surface Pressure Distribution

Description: Memorandum presenting an experimental investigation of a two-dimensional, 6.6-percent-thick, 6-foot-chord airfoil section equipped with suction slots for laminar-boundary-layer control. The section was designed to have favorable pressure gradients between the suction slots. The laminar boundary layer on the airfoil had the same extreme sensitivity to minute details of the model surface condition as has been found in other investigations.
Date: December 15, 1953
Creator: Loftin, Laurence K., Jr. & Horton, Elmer A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Some Features of Artificially Thickened Fully Developed Turbulent Boundary Layers with Zero Pressure Gradient

Description: Report gives an account of an investigation conducted to determine the feasibility of artificially thickening a turbulent boundary layer on a flat plate. A description is given of several methods used to thicken artificially the boundary layer. It is shown that it is possible to do substantial thickening and obtain a fully developed turbulent boundary layer, which is free from any distortions introduced by the thickening process, and, as such, is a suitable medium for fundamental research.
Date: September 15, 1950
Creator: Klebanoff, P. S. & Diehl, Z. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Influences on the Height of the Stable Boundary Layer as seen in LES

Description: Climate models, numerical weather prediction (NWP) models, and atmospheric dispersion models often rely on parameterizations of planetary boundary layer height. In the case of a stable boundary layer, errors in boundary layer height estimation can result in gross errors in boundary-layer evolution and in prediction of turbulent mixing within the boundary layer.
Date: June 15, 2004
Creator: Kosovic, B & Lundquist, J
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Surface Layer Turbulence During a Frontal Passage

Description: Some recent investigations have begun to quantify turbulence and dissipation in frontal zones to address the question of what physical mechanism counteracts the intensification of temperature and velocity gradients across a developing front. Frank (1994) examines the turbulence structure of two fronts that passed a 200m instrumented tower near Karlsruhe, Germany. In addition to showing the mean vertical structure of the fronts as they pass the tower, Frank demonstrates that there is an order of… more
Date: June 15, 2004
Creator: Piper, M & Lundquist, J K
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Turbulences in boundary plasmas

Description: We simulate boundary plasma turbulence using a 3D turbulence code BOUT and a linearized electromagnetic instability shooting code BAL. The code BOUT solves fluid equations for plasma vorticity,density, ion temperature and parallel momentum (along the magnetic field), electron temperature, and parallel momentum. A realistic DIII-D X point magnetic geometry is used. The focus is on the possible local linear instability drivers and turbulence suppression mechanisms from L to H mode. Comparison is … more
Date: May 15, 1998
Creator: Xu, X. Q., LLNL
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A procedure for the automatic estimation of mixed layer height.

Description: The daytime mixed layer results from mechanical and thermal turbulence processes driven by differences in air-surface temperature and moisture. As such, the height of the mixed layer (z{sub i}) is a measure of the effectiveness of energy transfer from the sun to the earth's surface and, in turn, to the lower atmosphere (Stun, 1989). Maximum daytime values for z{sub i} in the region of the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) vary from less than 100 m in cloudy, moist, … more
Date: April 15, 1998
Creator: Coulter, R. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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