中文摘要：

通过3体滑行艇不同滑行面形式的对比模型试验,研究了断阶对3体滑行艇阻力性能及运动姿态的影响,比较了3体和单体滑行艇在有无断阶时的阻力性能特点,并对船体2侧喷溅进行了观察.结果表明：无断阶3体滑行艇在第2个阻力峰出现以前阻力与航态的变化趋势同无断阶单体滑行艇一致.加入断阶后3体滑行艇阻力与航态的变化与单体滑行艇加入断阶后的变化不同,断阶3体滑行艇第2个阻力峰消失,阻力随速度的提高而增大,断阶数目越多阻力增长越快;航态变化趋势与无断阶类似,第2次航态出现较大变化的时间随断阶数目的增多而提前.试验中观察发现：无断阶方案的2侧槽道有使喷溅流整顺和形成气垫的作用,而有断阶方案的槽道内喷溅流混乱.

英文摘要：

The influence of different for steps on resistance performance and sailing state of trimaranplaning boat was studied. The characteristics of hydrodynamic performances of trimaran-planing boat and monomer planning boat with or without steps were compared, and their wave spraying was observed. The results show that the trend of resistance performance and sailing state of trimaran-planing boat without steps is the same as those of monomer planning boat before the second drag hump appears. The effects on hydrodynamic performance of adding bottom steps to trimaran-planing and monomer planning boats are different. The second drag hump of stepped trimaran-planing boat disappears and resistance increases with increasing speed. The greater the number of steps, the faster the drag increases. The trend of change on sailing state is similar to that of non-stepped trimaran-planing boat. The second greater change on sailing state appears earlier with increasing of number of step, and the observations in the tests showed that the channels under the non-stepped trimaran-planing boat benefit in regulating the spraying stream forming air-chamber like cushions, which may be the cause of drag reducing in this case, and the spraying stream in multi-stepped trimaran-planing boats appears turbulent.