Page 108 - Theory and Design of Air Cushion Craft
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92 Steady drag forces
0.4 0.5 0.6 0.7 0.8 0.9 1.0
Fig. 3.7 Cushion wave-making drag ratio as a function of equivalent Froude Number. [22]
3.5
1: d/a=°° b/a=0.5
3.0 h 2:d/a=l.O
3: d/a=0.5
4: d/a=0.25
a: cushion length
2.0 b: cushion beam
d\ water depth
1.0
Fig. 3.8 Influence of water depth on cushion wave-making drag.
without special difficulty. Figure 3.10 shows the trial results of a full-scale craft
SES-IOOB. It was found that the drag decreased as the craft accelerated. The drag
over both shallow and deep water is presented in Fig. 3.11.
