Three-dimensional (3D) unsteady features of turbulent nitrogen convection in an industrial hi.-h-pressure, liquid-encapsulated Czochralski (HPLEC) InP growth system have been studied using a 3D unsteady model based on the large eddy simulation (LES) approach. The conjugated simulation of the gas flow, the encapsulant motion and heat transfer in the crystal has been performed for varying gas pressure. A strong effect of gas convection on the temperature distribution in the crystal, and on the heat loss from the crystal and encapsulant surfaces has been revealed. Non-axisynimetric unsteady fluctuations of the temperature gradients in the crystal, produced by changes of the gas flow, have been observed, which can be responsible for dislocation generation in the growing crystal. (c) 2005 Elsevier B.V. All rights reserved.