Heat Transfer Rates

Figure 4.37 shows a plot of the local Nusselt number on the vertical face of the copper block determined using the boundary- layer thickness. The average values of the Nusselt number on the vertical face and Nusselt number at the midpoint of the chip corresponding to the three Rayleigh numbers are given in Table 6. Except for a block temperature of these are larger than the corresponding average for the entire heater. At the boundary- layer thickness at the leading edge is nonzero, resulting in a low Nusselt number over the vertical face of the copper block.

Figure 4.37: Local Nusselt number as a function of distance along the copper block.

Table 6: Average and Midpoint Nusselt Numbers an the Vertical Face of the Copper Block

	60	80.2	101
	2477	3349	3894
	13.5	30.8	28.6
	10.5	23.0	19.0