Table 2.

Grid independence test for sheet and tube collector.

No	Nodes	Nu
1	482,154	83.58
2	812,010	70.92
3	1,565,841	67.44
4	2,245,615	58.82
5	2,945,462	56.61
6	3,132,341	56.39
7	3,571,657	56.28