Fluid flow and heat transfer in gas jet quenching of a cylinder

Heat treatment by quenching of individual metallic parts with multiple impinging gas jets is an environmentally friendly alternative to conventional surface hardening and quenching in liquids. In the present investigation the gas flow field and simultaneous heat transfer process in gas quenching is studied by numerical simulation for surface treatment of a cylindrical sample geometry. Aim of the investigation is the evaluation of optimized flow conditions and nozzle arrangements to achieve: a maximum overall heat release (high integral heat transfer rates) to maximize the quenching efficiency; a local smooth distribution of the cooling process (spatially homogeneous heat transfer) for avoidance of spatial hardness variations. These aims are achieved by derivation of an optimized nozzle arrangement and appropriate operation conditions of the gas jet array with respect to the three dimensional sample geometry of a cylinder to be quenched.