“…Equation ( 10) represents Newton's law of cooling, where q denotes the heat-flux density. The convective heat transfer coefficient was defined as shown in Equation (11), where Nu denotes the Nusselt number, k represents the thermal conductivity of the fluid (air), andL represents the characteristic length, which corresponded with the length of the film heater (152.4 mm). For free convection over a vertical plate, the Nusselt number follows Equation ( 12) [17].…”