Thermal and solutal Marangoni convection in In-Ga-Sb system

In order to clarify the velocity feature of surface-tension-driven-flow caused by temperature differences (thermal Marangoni convection) and concentration differences (solutal Marangoni convection), the rectangular double-crucible system was developed. Measurements of surface velocities of thermal and solutal Marangoni convection in In-Ga-Sb melt were performed using the system. For solutal Marangoni convection, we solved the model in which the additional material spreads on the initial material, using a similarity parameter and a dimensionless stream function. As a result, the analytical result was in agreement with the experimental one. Moreover, we found that the typical surface velocity of solutal Marangoni convection is about 3-5 times higher than that of thermal Marangoni convection, and the results of both thermal and solutal convection could be discussed using dimensionless Reynolds (Re), Marangoni (Ma) and Prandtl (Pr) numbers. The relationship between the difference in surface tension and the surface velocity is that Re is proportional to Ma Pr-1/2 to the power of 2/3. (C) 1999 Elsevier Science B.V. All rights reserved.