Convection in horizontal flat channels of the vacuum vessel of the international thermonuclear experimental reactor (ITER)

The results are given of the experimental investigation of the intensity of heat transfer from the flat horizontal surfaces of a model of the vacuum vessel channel of the international thermonuclear experimental reactor (ITER). The channel height is varied from $12$ to $50$ mm, as well as its heated length ($1.02$ and $2.48$ m). The water flow velocities of $0.0066$ to $0.15$ m/s correspond to the values of $\mathrm{Re}=560-16600$. The specific heat flux on the heat-transfer surfaces is $1.3$–$24.4$ kW/m$^2$. The examined range of parameters is characterized by a significant temperature stratification of water over the channel height. Generalizing relationships are suggested based on the experimental results.