Natural Convection from a Helical Heating Coil to the Surrounding Fluid.

An experimental study is reported on natural convection heat transfer from a helical heating coil to the surrounding fluid. The coil is heated electrically and the surrounding fluid is selected to be water. The range of parameters are: Rayleigh number, ۸۷۹ ?£ Ra ?£ ۷۸۰۱۶۸, Prandtl number, ۴.۲۲ ?£ Pr ?£ ۱۰.۰۲, dimensionless coil diameter,۷.۶۹ ?£ Dave /d ?£ ۱۰.۷۷, number of coil rings, ۲ ?£ N ?£ ۸, and the dimensionless coil pitch ۱/d= ۱. The results are correlated by means of a modified Nusselt number. The proposed correlation is a convenient tool for estimating heat transfer from helical coils.

کلیدواژه ها:

Natural convection ، Free Convection ، heat transfer ، Helical Coil