2000 Volume 40 Issue Suppl Pages S115-S119
As a part of investigation on the scrap-base steel making, a computer model, which could simulate the transport phenomena in heating of a steel cylinder in a graphite vessel, was developed. The model describes the numerical modeling of two-dimensional coupled turbulent flow and heat transfer in a graphite vessel. The model uses generalized transport equations, which are applicable to the gas and solid region. The governing transport equations are solved simultaneously by the ANSYS package. This model allows calculation of the temperature distribution inside the gas and solid phase, as well as convective and radiative heat transfer coefficients. Launder and Spalding's default values have been used with satisfactory results. The effect of various factors, such as steel cylinder surface conditions, gas flow rate, on the heating rate has been discussed. The values of emissivity for different surface condition have been determined. Best fitting was obtained with an emissivity's value of 0.9 for black surface and 0.2 for the polished one. The radiative heat transfer coefficients obtained were 560 (for polished surface) and 640 W/m2K (for black surface), respectively. The convective heat transfer coefficients were in the range of 13 to 33.64 W/m2K, depending on the gas flow rate. The convective Nusselt number in dependence on the Reynolds and Prandtl numbers yielded to the following relation: Nu=0.75Re0.446Pr0.33.