1. 圓柱座標系統下τ rz 之物理意義? (5 分) 2. 何謂牛頓流體? (10 分) 3 ...

4. A fluid, ρ=1200 kg/m 3 , flows through a pump at 0.25 m 3 /s. The pump inlet is 0.3 m in diameter. Atthe inlet the pressure is 76 kPa. The pump outlet, 0.125 m in diameter, is 1.2 m above the inlet. Theoutlet pressure is 240 kPa.If the inlet and exit temperature are equal, how much power does thepump add to the fluid? (25 分 )

6. A 40-km-long pipeline delivers petroleum at a rate of 4000 barrels per day. The resulting pressuredrop is 3.45×10 6 Pa. If a parallel line of the same size is laid along the last 18 km of the line, what willbe the new capacity of this network? Flow in both case is laminar and the pressure drop remains 3.45×10 6 Pa. (20 分 ) (Hint: Using Hagen-Poiseuille equation)

Chapter 11. Dimensional Analysis‣ DimensionImportant Variables in Momentum TransferVariable Symbol DimensioniMass M MLength L LTime T TVelocity V L/tGravitational acceleration G L/t 2Force F ML/t 2Pressure P M/Lt 2Density ρ M/L 3Viscosityit μ M/LtSurface tension σ M/t 2Sonic velocity a L/t

Table 11.2 Common dimensionless i parameters in momentum transferName/SymbolDimensionless groupPhysical meaningReynolds number, Re Lvρ/μ Inertial force/Viscous forceEuler number, Eu P/ρv 2 Pressure Force/InertialforceCoefficient of skinfriction, CfFroude number, FrWeber number, WeMach number, M(F/A)/(ρv 2 /2)v 2 /gLρv 2 L/σv/CPressure Force/InertialforceInertial force/GravitationalforceInertial force/Surfacetension forceInertial/CompressibilityforceArea of applicationWidely applicable in ahost of fluid flowsituationsFlow involvingpressure differencesdue to frictionaleffectsFlows involving freeliquid surfaceFlows with significantsurface tension forceFlows with significantcompressibilityeffects