NASA Scientific and Technical Aerospace Reports

experimental dataset provides essential flow-field information for the validation of near-field inputs to noise prediction tools.
Author
Unsteady Flow; Particle Image Velocimetry; Leading Edge Slats; Wind Tunnel Models; Aerodynamics; Characterization
20040073477 QSS Group, Inc., Cleveland, OH, USA
TopMaker: A Technique for Automatic Multi-Block Topology Generation Using the Medial Axis
Heidmann, James D., Technical Monitor; Rigby, David L.; April 2004; 16 pp.; In English; Fourth Joint Fluids Engineering
Conference, 6-10 Jul. 2003, Honolulu, HI, USA
Contract(s)/Grant(s): NAS3-00145; WBS 22-714-09-11
Report No.(s): NASA/CR-2004-213044; FEDSM2003-45527; E-14481; No Copyright; Avail: CASI; A03, Hardcopy
A two-dimensional multi-block topology generation technique has been developed. Very general configurations are
addressable by the technique. A configuration is defined by a collection of non-intersecting closed curves, which will be
referred to as loops. More than a single loop implies that holes exist in the domain, which poses no problem. This technique
requires only the medial vertices and the touch points that define each vertex. From the information about the medial vertices,
the connectivity between medial vertices is generated. The physical shape of the medial edge is not required. By applying a
few simple rules to each medial edge, the multiblock topology is generated with no user intervention required. The resulting
topologies contain only the level of complexity dictated by the configurations. Grid lines remain attached to the boundary
except at sharp concave turns where a change in index family is introduced as would be desired. Keeping grid lines attached
to the boundary is especially important in the area of computational fluid dynamics where highly clustered grids are used near
no-slip boundaries. This technique is simple and robust and can easily be incorporated into the overall grid generation process.
Author
Grid Generation (Mathematics); Multiblock Grids; Topology; Computational Fluid Dynamics; Two Dimensional Models
20040073486 NASA Glenn Research Center, Cleveland, OH, USA
Predictions for the Effects of Free Stream Turbulence on Turbine Blade Heat Transfer
Boyle, Robert J.; Giel, Paul W.; Ames, Forrest E.; May 2004; 23 pp.; In English; Turbo Expo 2004, 14-17 Jun. 2004, Vienna,
Austria
Contract(s)/Grant(s): WBS 22-714-30-10
Report No.(s): NASA/TM-2004-213079; GT2004-54332; E-14555; No Copyright; Avail: CASI; A03, Hardcopy
An approach to predicting the effects of free stream turbulence on turbine vane and blade heat transfer is described. Four
models for predicting the effects of free stream turbulence were in incorporated into a Navier-Stokes CFD analysis. Predictions
were compared with experimental data in order to identify an appropriate model for use across a wide range of flow conditions.
The analyses were compared with data from five vane geometries and from four rotor geometries. Each of these nine
geometries had data for different Reynolds numbers. Comparisons were made for twenty four cases. Steady state calculations
were done because all experimental data were obtained in steady state tests. High turbulence levels often result in suction
surface transition upstream of the throat, while at low to moderate Reynolds numbers the pressure surface remains laminar.
A two-dimensional analysis was used because the flow is predominately two-dimensional in the regions where free stream
turbulence significantly augments surface heat transfer. Because the evaluation of models for predicting turbulence effects can
be affected by other factors, the paper discusses modeling for transition, relaminarization, and near wall damping. Quantitative
comparisons are given between the predictions and data.
Author
Computational Fluid Dynamics; Heat Transfer; Turbine Blades; Free Flow; Mathematical Models; Turbulence; Rotor
Dynamics
20040073495 NASA Marshall Space Flight Center, Huntsville, AL, USA
An Overview of the Materials Science Research at the Marshall Space Flight Center Electrostatic Levitator Facility
and Recent CDDF Efforts
Biological and Physical Space Research Laboratory 2002 Science Review; December 2003, pp. 17; In English; See also
20040073490; No Copyright; Abstract Only; Available from CASI only as part of the entire parent document
Containerless processing is an important tool for materials research. The freedom from a crucible allows processing of
liquid materials in a metastable undercooled state, as well as allowing processing of high temperature and highly reactive
melts. Electrostatic levitation (ESL) is a containerless method which provides a number of unique advantages, including the
ability to process non-conducting materials, the ability to operate in ultra-high vacuum or at moderate gas pressure (approx.
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