On the transition from conduction to convection regime in a cubical enclosure with a partially heated wall

Transient thermal characteristics of airborne electronic equipment with discrete hot bands in square cavities

“…The results in steady-state regime obtained in the present study are close to those of Frederick et al [22] who looked at the case of a discrete isothermal square source, with a side s, disposed on the vertical wall of a right cavity (a = 0°), the rest of the plate being adiabatic as well as the channel of the enclosure. The cold wall is facing the hot one as in the cavity under consideration here.…”

“…Its extrapolation to Ra = 1.07 Â 10 7 leads to Nu ¼ 14:12. The difference with the values of the present study is 6.2%, which reduces further if the results in [22] are extrapolated for values of s/H > 0.7 that are closer to our values. With a still equals 0, the comparison is now conducted with the work of Tou et al [23], which considers a geometry close to the one treated in the present study but with 3 Â 3 active elements on the hot wall.…”

“…The cold wall is facing the hot one as in the cavity under consideration here. In order to compare, we have taken from [22] the case for which the ratio between the surface area of the discrete source and the total area of the hot wall (s/H) 2 is closer to the present study, that is 3/5. This gives a ratio s/H % 0.77.…”

“…This gives a ratio s/H % 0.77. The closest value of this ratio proposed in [22] is s/H = 0.7, for which a correlation of Nu ¼ 0:1121Ra 0:2988 , valid for 10 5 6 Ra 6 10 7 , is recommended in the steady-state regime. Its extrapolation to Ra = 1.07 Â 10 7 leads to Nu ¼ 14:12.…”

Numerical and experimental study of natural convection in tilted parallelepipedic cavities for large Rayleigh numbers

“…This has been observed in other studies for particular thermal and geometric configurations. Frederick et al [26] showed for example that 3D effects can significantly influence the flows since, for some combinations, the peak value of the w component can exceed the 61% of the peak value of u and more than a 37% of the peak value of the v component.…”