Seminarium Zakładu Mechaniki i Fizyki Płynów Control of a thermocapillary instability prof. Gustav Amberg, Dept of Mechanics, KTH Stockholm czwartek, 8 maja 2003

Thermocapillary (Marangoni) convection is the fluid motion that is caused by a temperature gradient along a free surface. In pure liquids the surface tension typically decreases with increasing temperature, and the free surface is thus pulled towards cold regions. This is a common source of convection in processes such as crystal growth and welding. In some applications it is important to maintain a steady time independent flow, and thus to suppress instabilities leading to oscillatory or chaotic flow. In this talk I will review some typical thermocapillary instabilities related to crystal growth processes. I will also describe our recent efforts to introduce a feedback control to stabilize the flow.