Table 9: Average Nusselt Number as a Function of Fourier Number
 |
 |
6.34 |
11.5 |
35.7 |
91.3 |
|
2.21 |
3.42 |
3.65 |
3.45 |
|
2.06 |
3.11 |
2.45 |
3.68 |
|
2.13 |
3.26 |
3.06 |
3.56 |
 |
|
9.14 |
13.7 |
20.3 |
60.94 |
|
2.24 |
2.52 |
4.53 |
4.89 |
|
2.64 |
2.79 |
3.77 |
3.81 |
|
2.44 |
2.66 |
4.15 |
4.35 |
 |
|
8.93 |
31.9 |
47.4 |
65.7 |
|
2.87 |
4.47 |
4.54 |
5.89 |
|
3.33 |
4.49 |
4.31 |
4.26 |
|
3.1 |
4.48 |
4.42 |
5.07 |
The increase in Nusselt number is however not found to be monotonic. The thermal field is seen to be symmetric with respect to the vertical axis dividing the cavity only at the lowest Rayleigh number (Ra=8.79 x 103). It is not symmetric at higher Rayleigh numbers, both during the transient as well as steady state. This is also seen in the average Nusselt numbers obtained for each half of the cavity. Hence, analyses that assume symmetry are likely to yield incorrect results.
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