已知:[NPSH]r=3.5m,(Hf吸+u12/2g)=3J/N,Hg=3m,P0=90kPa,tH2O=20℃。求:是否汽蝕?
已知:n=1480r/min時,泵He=38.4-40.3qv2(He-m,qv-m3/min),ΔP/ρg=16.8m,Φ76×4mm,L=1360m,λ=0.03。求: (1)輸液量qv; (2)當n’=1700rpm時為qv’