普通钢管长多少米? 管内壁糙,糙率n=0.012,管道摩阻S=10.3n^2/d^5.33=10.3*0.012^2/0.1^5.33=317.1压力0.16Mpa,相当于水头H=16m流量 Q=[H/(SL)]^(0.5)=[16/(317.1*25)]^(0.5) = 0.045 m^3/s = 162 m^3/h管道流速V=4Q/(3.1416d^2)=4*0.045/(3.1416*0.1^2)= 5.73 m/s