Equation Number | Author [Reference] | Explicit Models | Applicable Range of Re and ε/D | Classification |
2 | Romeo, Royo and Monzon [9] |
| 3 × 103 ≤ Re ≤ 1.5 × 108 0 ≤ ε/D ≤ 5 × 10−2 | Extremely accurate |
3 | Serghides [15] | , , , | Not specified | Extremely accurate |
4 | Chen [11] |
| 4 × 103 ≤ Re ≤ 4 × 108 10−7 ≤ ε/D ≤ 5 × 10−2 | Very accurate |
5 | Buzzelli [16] | ; where, | 3 × 103 ≤ Re ≤ 3 × 108 0 ≤ ε/D ≤ 5 × 10−2 | Extremely accurate |
6 | Zigrang and Sylvester [14] |
| 4 × 103 ≤ Re ≤ 108 4 × 10−5 ≤ ε/D ≤ 5 × 10−2 | Extremely accurate |
7 | Barr [19] |
| Not specified | Very accurate |
8 | Fang, Xu, Zhou [13] |
| 3 × 103 ≤ Re ≤ 1.5 × 108 0 ≤ ε/D ≤ 5 × 10−2 | Very accurate |
9 | Shacham [20] |
| 4 × 103 ≤ Re ≤ 4 × 108 | Moderately accurate |
10 | Sonnad and Goudar [21] | ; where | 4 × 103 ≤ Re ≤ 108 10−6 ≤ ε/D ≤ 5 × 10−2 | Moderately accurate |
11 | Manadilli [23] |
| 5.235 × 103 ≤ Re ≤ 108 0 ≤ ε/D ≤ 5 × 10−2 | Less accurate |
12 | Ghanbari, Farshad and Rieke [17] |
| 2.1 × 103 ≤ Re ≤ 108 0 ≤ ε/D ≤ 5 × 10−2 | Less accurate |
13 | Churchill [24] | ; where, | Re > 0 0 ≤ ε/D ≤ 5 × 10−2 | Less accurate |