Example (3.2) A fluid (p = 960 kg/m³) is flowing steadily through tube. The section diameters are d, = 100mm and d,= 80 mm. The gauge pressure at 1 is p, =200 kPa. The velocity at 1 is u,= 5 m/s. The tube is horizontal (z=z). What is the gauge pressure at %3D section 2?

In Fig. 1.7, if the fluid is glycerin at 20 ° C and the widthbetween plates is 6 mm, what shear stress (in Pa) isrequired to move the upper plate at 5.5 m/s? What is theReynolds number if L is taken to be the distance betweenplates?

A hydraulic pump is shown in the following Figure, flow rate is 25 L/min, the diameter of suction pipe is 25mm, and the suction port of pump is higher than the oil surface of tank, the height is h, Kinematic viscosity of oil is 30×10“m²/s, density of oil is 900kg/m³. Only the pressure loss along the straight suction pipe with length h is 75 considered, if the vacuum degree at the inlet of pump is not bigger than 4500P ( 2 = R. a = 2, g=9.8) (1) Calculate the flow velocity in the suction pipe; (2) Judge the flow state in suction pipe; (3) Calculate the pressure loss along the straight suction pipe; (4) Calculate the oil absorption height h.