大多数河工模型都需要加糙才能满足河工模型的阻力相似，因此模型加糙效果的好坏直接关系着河工模型模拟的效果和精度。通过水槽试验对Y型加糙体阻力特性进行了深入研究。研究结果表明：其糙率具有一个较大的调整范围，且随着加糙间距的增加水力阻力减小，减小的幅度越来越小，最后基本不变；雷诺数在3 500左右水流进入阻力平方区，进入阻力平方区后，随着相对淹没度的增大水力阻力减小，最后达一定值。

Roughening in river models is a very important method to meet resistance similarity. A flume experimental study is conducted for the hydraulic resistance of roughening elements shaped as letter “Y”. The results show that this kind of roughening elements can possess a wide range of roughness, and the hydraulic resistance decreases with the increase of space between roughness elements, but reduces slowly to a constant, and that flow enters into the turbulently rough zone when Reynolds number reaches about 3 500, in which the hydraulic resistance decreases with increase of relative submergence degree, reducing slowly to a constant too.