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Experimental study of buoyant-thermocapillary convection in a rectangular cavity
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Braunsfurth, Manfred G. Homsy, George M. |
| Copyright Year | 1996 |
| Description | The problem of buoyant-thermocapillary convection in cavities is governed by a relatively large number of nondimensional parameters, and there is consequently a large number of different types of flow that can be found in this system. Previous results give disjoint glimpses of a wide variety of qualitatively and quantitatively different results in widely different parts of parameter space. In this study, we report experiments on the primary and secondary instabilities in a geometry with equal aspect ratios in the range from 1 to 8 in both the direction along and perpendicular to the applied temperature gradient. We thus complement previous work which mostly involved either fluid layers of large extent in both directions, or consisted of investigations of strictly two-dimensional disturbances. We observe the primary transition from an essentially two-dimensional flow to steady three-dimensional longitudinal rolls. The critical Marangoni number is found to depend on the aspect ratios of the system, and varies from 4.6 x 10(exp 5) at aspect ratio 2.0 to 5.5 x 10(exp 4) at aspect ratio 3.5. Further, we have investigated the stability of the three-dimensional flow at larger Marangoni numbers, and find a novel oscillatory flow at critical Marangoni numbers of the order of 6 x 10(exp 5). We suggest possible mechanisms which give rise to the oscillation, and find that it is expected to be a relaxation type oscillation. |
| File Size | 404069 |
| Page Count | 6 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19970000400 |
| Archival Resource Key | ark:/13960/t1gj4f146 |
| Language | English |
| Publisher Date | 1996-09-01 |
| Access Restriction | Open |
| Subject Keyword | Fluid Mechanics And Heat Transfer Oscillating Flow Cavities Three Dimensional Flow Temperature Gradients Buoyancy Convective Flow Capillary Flow Flow Geometry Aspect Ratio Marangoni Convection Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
