Aerodynamics of cooling of blown film bubbles

Numerical simulation of turbulent flow of jet impinging at various angles on blown film bubbles has been performed. The air flow from various types of air rings has been studied. The streamline pattern for external cooling as well as heat transfer coefficients have been determined from the solution of the differential equations for the conservation of mass, momentum and energy of the air jets studied. The turbulent flow has been calculated using the renormalization group (RNG) k-ε model. Venturi effect (local creation of low pressure due to high speed flow at narrow passages) has been studied.