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A person drops 3 aluminum balls of diameters 2 mm, 4 mm and 10 mm into a tank filled with glycerin at
60.4 mm/s, respectively. The measurements are to be compared with theory using Stokes law for drag force acting on a spherical object of diameter D expressed as
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Fluid Mechanics: Fundamentals and Applications
- Engine oil at 40 C flows over a 5-m-long flat plate with a free-stream velocity of 2 m/s. Determine the drag force acting on the top side of the plate per unit width. The density and kinematic viscosity of oil at 40 C are 876 kg/m^3 and 2.458 x 10 m^-4/s respectively.arrow_forwardConsider a large dirigible (like the Goodyear blimp) with length L = 240 m, and average diameter D = 40 m moving at a speed U = 135 km/hr at high altitude where the air density is p = 0.9 kg/m³ and the dynamic viscosity is u = 1.8 x 10-5 N – s/m². Because of the large size of the blimp and its large radius of curvature the primary forces acting on it are due to shear stresses at the surface, and the entire surface area can be approximated by its layout as a flat plate. Determine the drag force acting on the dirigible due to shear stresses, and the power required for the engine.arrow_forwardWhat is the most important criterion for use of the modified pressure P′ rather than the thermodynamic pressure P in a solution of the Navier–Stokes equation?arrow_forward
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- Q9arrow_forwardCarrow_forwardA long circular cylinder rotates at a constant angular velocity of 100 rad/s while subjected to a uniform cross flow of air at a velocity of 15 m/s as shown. If the density of the air is 1.20 kg/m², find the lift per unit length of cylinder. y U= 15 m/s @ = 100 rad/s R = 0.25 m airarrow_forward
- i have fluid mechanics exam tomorrow but i couldnt understand first 3 part of that question. thank you so much who can solve this for me .arrow_forward1. The Stokes-Oseen formula for drag force Fon a sphere of diameter D in a fluid stream of low velocity V, density p, and viscosity u is: 9T F = 3TuDV + 16PD? Is this formula dimensionally homogenous? 2. The efficiency n of a pump is defined as the (dimensionless) ratio of the power required to drive a pump: QAp input power Where Q is the volume rate of flow and Ap is the pressure rise produced by the pump. Suppose that a certain pump develops a pressure of Ibf/in? (1ft = 12 in) when its flow rate is 40 L/s (1L =0.001 m). If the input power is 16hp (1hp = 760 W), what is the efficiency?arrow_forwardA jet airplane weighs 160,000 N and has a zero-lift drag coefficient of 0.008 and a wing area of 42 m^2. At 100 m/s at sea level, the rate of climb is 11.5 m/s. The thrust developed by the engines is equal to 27,000 N. Determine the maximum rate of climb and the corresponding flight speed at sea level .arrow_forward
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