Ultrafast cooling of a hot steel plate using Cu-Al layered double hydroxide nanofluid jet

The current work contains a detailed experimental investigation on the alteration of heat transfer characteristics during jet impingement cooling of a hot steel plate using Copper-Aluminium layered double hydroxide (Cu-Al LDH) nanoparticle as an additive. The experiments have been performed on steel plate having initial surface temperature well above the Leidenfrost point. A new breed of nanoparticle named Cu-Al LDH has been prepared via co-precipitation method and the effect of its concentrations on surface tension, thermal conductivity and viscosity have been studied. The results show that the cooling rate increases with the increasing concentration of nanoparticle in coolant upto an optimum level beyond which it declines. A maximum cooling rate of 154 °C/s has been achieved at a nanoparticle concentration of 120 ppm which is 41% higher than that obtained with pure water. The study reveals that ultrafast cooling rate can be achieved by Cu-Al LDH nanofluid jet which is essential for the production of high strength steel for various industrial applications.