流体流动基本规律

Vs=u A4d2u=u=4 Vs d2或 d=4Vs us=u A4d2u=0.0997m=99.7mmd=4 uVVs流体本身具有的 能量系统与外界交换的能量流体的能量)(212Jmu)/(212kgJpvugzU0Z112Z2=U1+gZ1+2u12+p1v1+Qe+We=U2+gZ2+2u22+p2v2U1+gZ1+2u12+p1v1+Qe+We=U2+gZ2+2u22+p2v2=Q e-12p dU12p d换热器提供给流体的热量Qe能量损失h f:流体在1-1与2-2截面流动时，克服流动阻力消耗的机械能Qe-12pd=We -gZ+u22+pfhp12pd+p=12dpp12dp=We -gZ+u22+fhp12d pp-=p=p12d ppp2p1=We -gZ+u22+fhpu122gZ1+p1u222gZ2+p2=+We(J/kg)fh+u122gZ1+p1u222gZ2+p2=mu122mgZ1+p1=+Wefhmmu222mgZ2+p2+mmmu122gZ1+p1u222gZ2+p2=+We(J/kg)fh+u122gZ1+p1=+Wefhggu222gZ2+p2+ggu122gZ1+p1=+fgu222gZ2+p2+gHeHu122gZ1+p1u222gZ2+p2=+Wefh+u122gZ1+p1u222gZ2+p2=gZ1+p1gZ2+p2=u122gZ1+p1u222gZ2+p2=+Wefh+u122gZ1+p1u222gZ2+p2=u122+p1u222+p2=u22Rg1d2d1（）4-=0-()u2d224Vs=2Rg1d2d1()4-0-()=d2242Rg1d2d1)4-0-()d2=42(2222121122PugZPugZ 2.14905220.1333522221uu(a)137332122uu2211AuAu22112dduu2102.008.0u(b)1612uu smu/34.7112143600udVh34.708.0436002hm/8.1323u122gZ1+p1u222gZ2+p2=+Wefh+u122gh +u222=fh+29.81u12u22=fh+h2-gg=1+209.81=2.09(m)u122gZ1+p1u222gZ2+p2=+Wefh+u122+p1u222+p2=u2=VsA2=0.536004d22=0.536000.0032=19.6m/s4u1=VsA1=0.536004d21=0.5360040.022=0.44m/su122p1u22+p2=-=215820+1000(0.442-19.62)2=23837 Pa u2=VsA204 d2=4(68-42)102-6 3600=1.97(m/s)VsWe=p2gZ2+u22+2hf+2=159.81+1.972+120+(-26670)1200