[ ko is at T = 20oC ]
O'Connor and Dobbins (1958): ko = 3.93 V0.5 D-1.5
[0.3 m < D < 9 m; 0.15 m/s < V < 0.5 m/s]
Churchill et al. (1962): ko = 5.23 V D-1.67
[0.6 m < D < 3 m; 0.55 m/s < V < 1.5 m/s]
Owens et al. (1964): ko = 5.32 V0.67 D-1.85
[0.1 m < D < 3 m; 0.03 m/s < V < 1.5 m/s]
Tsivoglou and Wallace (1972): ko = 31,000 VS
[0.3 m < D < 0.9 m; 0.03 m3/s < Q < 0.3 m3/s]