Use of a Water Channel for Model Tests on Planing Hulls

A comparison has been made of the resistance characteristics of two of the DTMB series 62 planing hulls obtained from measurements made in a high-speed recirculating water channel and a towing tank. The results showed good agreement at the DTMB standard displacement ratio, provided a correction was applied for shallow water effects due to the restricted working section depth. The results suggest that, with the present size models, resistance measurements can be made for a displacement ratio (AP/V2/3} not less than 7.0. Further work is envisaged on the use of smaller models, in order to extend the range of displacement ratios that may be investigated. Nomenclature A P = projected planing bottom area, excluding spray strips BP = beam over chines, excluding spray strips BPA = mean breadth over chines ,AP/LP BPT = breadth over chines at transom, excluding spray strips BpX = maximum breadth over chines, excluding spray strips Fv = Froude number based on volume displacement,