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On the drag of model dendrite fragments at low reynolds number
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Degroh II, H. C. Weidman, P. D. Zakhem, R. |
| Copyright Year | 1993 |
| Description | An experimental study of low Reynolds number drag on laboratory models of dendrite fragments has been conducted. The terminal velocities of the dendrites undergoing free fall along their axis of symmetry were measured in a large Stokes flow facility. Corrections for wall interference give nearly linear drag vs Reynolds number curves. Corrections for both wall interference and inertia effects show that the dendrite Stokes settling velocities are always less than that of a sphere of equal mass and volume. In the Stokes limit, the settling speed ratio is found to correlate well with primary dendrite arm aspect ratio and a second dimensionless shape paremeter which serves as a measure of the fractal-like nature of the dendrite models. These results can be used to estimate equiaxed grain velocities and distance of travel in metal castings. The drag measurements may be used in numerical codes to calculate the movement of grains in a convecting melt in an effort to determine macrosegregation patterns caused by the sink/float mechanism. |
| File Size | 1400629 |
| Page Count | 38 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19930010785 |
| Archival Resource Key | ark:/13960/t8md3v894 |
| Language | English |
| Publisher Date | 1993-02-01 |
| Access Restriction | Open |
| Subject Keyword | Metallic Materials Low Reynolds Number Drag Dendritic Crystals Precipitation Chemistry Melts Crystal Growth Castings Microstructure Cast Alloys Solidification Stokes Flow Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
