... ()3 1, 1 , , 1 1, 1 4 1, , 1, 22 ()(2 2 ) ( ) ,i j ij ij i jij ij ijru r t u u ruru r u ru t uββ−+ + ++−+∞−+++Δ − =+− + +Δ (4 .10 ) ()33 1, 1 1, 1, , 1 1, 1 4 1, , 1, 22 ()( ... ()3 1, 1 , , 1 1, 1 4 1, , 1, 22 () ()(2 2 ) ( ) ( ) ,ij ij ij ijij ij ijru r t u t u ruru r u ru t u t uβαβα−+ + ++−+∞∞−+++Δ +Δ − =+− + +Δ +Δ (4 .13 ) ()33 1, 1 1, 1, , 1 1, 1 4 1, ... present present 10 3 1. 0 710 1. 0700 1. 0 712 1. 0 71 1042.0537 2.0542 2.0564 2.078 10 54.3329 4.33 71 4.3432 4. 510 10 68.6678 8.6407 8.6792 9.032Table 2. Natural convection of air and water in a...