Question

2 Pipe flow [6 points) A liquid with SG 0.96, H = 9.2 x 10-Nsm ?, and vapor pressure Pu 8000 Nm-2 (absolute) is drawn into the syringe as is indicated in figure 3. What is the maximum flowrate if cavitation is not to occur in the syringe? Assume the flow is laminar. Neglect minor losses. Assume that the velocity of the piston is negligible compared to the velocity in the needle. Atmospheric pressure is Patm 101 325 Nm-2. = I

Answer 1

solution: Pi Y=0.96, M2 9.2410" N sni?, Pu= 8000 Nswi? Patm = 101.325 Nsni² Applying energy equation between reservoir darum and piston of syrenge, +2i = f 2 + 1 2 + 2q + he 29 Howrates will be monimum lachen P2 = P2 = 8000 Nsui? he the minor But, heminar 20 (As per problem stalement) tevi? vi? + > the major al major z hl Dx 2g 644 EVID -4 - 64x9.2810 0.265 for daminer flowrate, of 64 :$ As per continuity equation, 0.96X1000XV X0.25X15 3 VI AIVIE A2 V2 ::02: Alyce v = (0:2) v VI A2 V2 = 0.000625 Vi ño

solving energy equation, we get 101325 - 8000 0.12 + 0.96X1000x9,81 0.24680 1 142 249.81X0.25 x103 XVI i. g.g) 20.12 + 5.015 vi :. Vi= 1.952 mis Flownali Q = Aiva = (0,2153153) *1.952 Q = 9.577x108 wils