The effect of gravitational modulation on convection in vertical Bridgman growthDuring vertical directional solidification of a binary alloy at constant velocity, buoyancy driven solutal convection may occur due to the solute gradient associated with the solidification process. This problem is further complicated if time periodic forcing is considered, which is relevant to materials processing in a microgravity environment or as a means of dynamic control of flow instabilities. The effect of time periodic modulation is studied by introducing a gravitational acceleration which is a sinusoidal function of time. The onset of solutal convection is treated by a stability analysis of the linearized governing equations and boundary conditions. Solutions are obtained numerically by employing two distinct computational implementations of Floquet theory. Results for materials with large Schmidt number are presented, and an analysis for large frequency and large Schmidt number yields a more complete description of the behavior in this relevant limit.
Document ID
19940005723
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Murray, Bruce T. (National Inst. of Standards and Technology Gaithersburg, MD, United States)
Coriell, S. R. (National Inst. of Standards and Technology Gaithersburg, MD, United States)
Mcfadden, G. B. (National Inst. of Standards and Technology Gaithersburg, MD, United States)
Wheeler, A. A. (Bristol Univ. United Kingdom)
Date Acquired
September 6, 2013
Publication Date
August 1, 1992
Publication Information
Publication: ESA, Proceedings of the 8th European Symposium on Materials and Fluid Sciences in Microgravity, Volume 2