参考答案和解析
正确答案:
D1=250mm=0.25m,D2=200mm=0.2m,pZ=0.04MPa,pY=0.33MPa,
Δh=0.3m,QV=0.14m3/s
V1=4QV/(πD21)=4×0.14/(3.14×0.252)=2.85(m/s)
V2=4QV/(πD22)=4×0.14/(3.14×0.22)=4.45(m/s)
H=pY/γ+pZ/γ+(V22-V21)/2g+Δh
=0.33×100+0.04×100+(4.452-2.852)/(2×9.81)+0.3=37.9(m)