抄録
The knowledge of forced convection transient heat transfer at various periods of exponential increase of heat input to a heater is important as a database for understanding the transient heat transfer process in a high temperature gas cooled reactor (HTGR) due to an accident in excess reactivity. The transient heat transfer coefficients for forced convection flow of helium gas over a horizontal cylinder were measured using a forced convection test loop. The platinum heaters with diameters of 0.7mm, 1.0mm, 2.0mm are heated by electric current with an exponential increase of Q_0exp(t/π). It was clarified that the heat transfer coefficient decreases when the diameter of test heater becomes larger, and it increases when the diameter of test heater becomes smaller. Semi-empirical correlations for quasi-steadystate and transient heat transfer were developed based on the experimental data.
