1979 Volume 1979 Issue 146 Pages 18-26
Non-linear properties of wave making resistance of wide-beam ships are studied with the sound examination of their physical phenomena to show the working limit of “linear” and “low speed” wave making resistance theories.
Vast experiments on series models of wide beam ships are undertaken including wave pattern analyses, flow field analyses and momentum loss measurements. Calculations of wave resistance, wave profiles and disturbance velocity distributions are carried out. From the examination of these analyses following three conclusions are obtained.
1) Effect of beam and draft upon wave making resistance of wide beam ships does not subject to the law derived from any present wave resistance theories. It is mainly attributed to the existence of non-dispersive waves tentatively called “free surface shock wave” in reference 2) and 3).
2) Free surface shock waves contribute to wave making resistance as a significant portion of momentum loss measured behind the ships.
3) The low speed theory developed by Baba is not always effective for hull form design. Its application should be limited within certain dimensions of hulls even in low Froude number region.
