Example 19.2 pump work calculation Known:SS;Q=10%W;Incompressible water;g=9.81 m/s2 p2=I atm Determine:Wev T2=23℃ V2=50m/s 2=5m Energy rate balance for CV: 0=0。-成+刻+()+的-对 v=(0.1)Wev P=I atm T1=20C Power washer (Av)=0.1 liter/s ↓(ayi/A50m/s D1=2.5cm negative 1-h2) -+g + 0.9 2 Wev =-1.54 kW -5m m (AV)/v ≈U(20C) (0.1L/s)/1.0018×10-3m/kg) 10-3m3 P=p2=1 atm C= 4.18 kJ/kg K Table A-3 1 0.1 kg/s h=△u+p4+y-一 h1-h2=c(T-T2)+vP-) = (4.18kJ/kg·K)(-3K)=-12.54kJ/kg 上降文通大学 March 28,2019 8 SHANGHAI JIAO TONG UNIVERSITYMarch 28, 2019 8 Energy rate balance for CV: Example 19.2 pump work calculation + -5m 50m/s (AV)1/A Table A-3 negative Power washer Known: SS; Q = 10% W; Incompressible water; g = 9.81 m/s2 Determine: Wcv      h u p v 0  v p