Experimental and numerical analysis of natural convection for Al–5.5% Cu alloy

Numerical and experimental investigations have been made for aluminum–5.5% copper (Al–5.5% Cu) binary alloy. During these investigations the effect of natural convection on the solidification process and the alloy structure are studied. No slip condition (stationary liquid metal) is proved to be the applicable condition at top boundaries of liquid metals exposed directly to the ambient (room temperature). Experimental and numerical results show good agreement. The results present, as the temperature increases the temperature gradient increases and so the natural convection currents. Natural convection flow is quantified and proved to work as a stirrer for temperatures higher or equal to 1100 K, i.e., eddy currents of the metal flow are strong enough to break the weak nuclei. So coarse grains are obtained in the solidified structure.