We study the feasibility of using crucible rotation with feedback control to suppress oscillatory flows in two prototypical vertical Bridgman crystal growth systems - a stabilizing configuration driven by a time-oscillatory furnace disturbance and a thermally destabilized configuration, which exhibits inherent time-varying flows. Proportional controllers are applied to the two systems, with volume-averaged flow speed chosen as the single controlled output and crucible rotation chosen as the manipulated input. Proportional control is able to significantly suppress oscillations in the stabilizing configuration. For the destabilized case, control is effective for small-amplitude flows but is generally ineffective, due to the exacerbating effect of crucible rotation on the time-dependent flows exhibited by this system.
|Original language||English (US)|
|Number of pages||8|
|Journal||Journal of Crystal Growth|
|State||Published - May 15 2004|
|Event||Proceedings of the Fourth International Workshop on Modeling - Kyushu, Japan|
Duration: Nov 4 2003 → Nov 7 2003
Bibliographical noteFunding Information:
This material is based upon work supported by the National Science Foundation under Grant No. 0201486. This work was also supported in part by the Minnesota Supercomputing Institute. PS expresses thanks to the University of Minnesota Graduate School for a Doctoral Dissertation Fellowship.
- A1. Control
- A1. Fluid Mechanics
- A1. Materials processing
- A1. Mathematical modelling
- A1. Nonlinear dynamics
- A2. Accelerated crucible rotation technique