Axisymmetric calculations of inert gas flow in a floating zone puller are carried out using an open source software package OpenFOAM. Transient axisymmetric melt flow in liquid silicon and quasi-stationary shape of silicon phase boundaries are calculated using a specialized program Hone. Additional heat losses at silicon surfaces caused by the gas flow are taken into account for argon and helium, while maintaining the height of molten zone by adjusting inductor current. Cooling causes an increase of electromagnetic force, heat sources and more intense melt now, while crystallization interface deflection decreases. The shear stress of gas now is found to be an order of magnitude weaker than electromagnetic and Marangoni forces. (C) 2014 Elsevier B.V. All rights reserved.