The roughness coefficient increases when the relativeroughness of the surface becomes larger under the same condition of discharge.
对于不同粗糙程度的壁面，在同一流量条件下的糙率系数会随着相对粗糙度的增大而增大。
2
The friction factor obtained from the experiments increases with the surface roughness increase when the relativeroughness is greater 1%.
实验结果表明当壁面粗糙度超过1%时摩擦系数随着壁面相对粗糙度的增加而增加。
3
Since if the frictional resistance coefficient is a function of relativeroughness, then the form resistance coefficient is independent of the Reynolds number.