Optimization of heat transfer and deformation control in aluminum plate heat treatment: effect of nozzle inclination angle

Abstract

The deformation behavior of an aluminum plate during heat treatment in an air-cushion furnace is numerically investigated, focusing on the effect of nozzle inclination angle. Validation of the numerical results was implemented with experimental data obtained from a specifically built experimental rig. The results reveal that at nozzle inclination angles of 30°, 45°, and 75°, the plate exhibits significant downward deflection in the central region, with the maximum deformation (60.3 mm) occurring at 45°. In contrast, a distinct wave-like deformation pattern with the minimal deformation (7.39 mm) arises at 60°, attributed to cross-flow interaction and the shear effect induced by plate motion. Consistency of the wave-like pattern is demonstrated at adjacent angles (57° and 62°). At an inclination angle of 60°, symmetric recirculating flows are reinforced, and the most uniform temperature distribution (average surface temperature of 463 K and temperature uniformity index of 0.757) is achieved. These findings highlight the critical role of nozzle inclination angle in reducing deformation and improving heat treatment quality, offering practical insights for industrial applications.