EML 3701 Fluid Mechanics I Final Exam A Spring 2022-2023 updated. 100% VERIFIED.

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I. (10 points, 1 point each question) Multiple Choice, No Partial Credit 1. The defining feature of fluids is: (answer C) (A) Fluids can fill a container of an arbitrary shape; (B) Fluids can defor... m without introducing any resistance; (C) Fluids cannot resist shear stress without continuously deforming; (D) Fluids can deform under pressure. 2. Consider a steady flow with velocity field u(y) shown in the figure. The dynamic viscosities of the three immiscible fluids are 1, 2 and 3. The velocity profile within each layer is linear. Choose one and only one correct answer for each question. The maximum shear stress appears at: (answer D) (A) Top. (B) Middle. (C) Bottom. (D) It is the same everywhere. 3. The physical meaning of Reynolds number is the ratio of: (answer A) (A) Inertia to viscous force. (B) Viscous force to inertia. (C) Body force to viscous force. (D) Viscous force to body force. 4. Which expression below has the unit of momentum? ∫ ⃗ (B) ∫ ⃗ ⃗ (C) ∫ ⃗ ⃗ (D) ∫ ⃗ 5. The formula /ρy 2 has the same unit as: (A) Force. (B) Pressure. (C) Time. (D) Frequency 6. The velocity profile for the steady laminar flow of water through a 0.4- m-diameter pipe is defined by m/s, where r is in meters. Determine the volumetric flor rate through the pipe. (answer A) (A) 0.188 m3 /s (B) 0.231 m3 /s (C) 0.315 m3 /s (D) 0.397 m3 /s 7. The manometer shown contains two liquids. The specific gravity of liquid A and liquid B are and , respectively . Calculate the deflection, h, when the applied pressure difference is . (answer D) (A) (B) (C) (D) y 1 2 3 U0 x EML 3701 Final Exam NAME___________________________________ page 5 8. The velocity distribution for laminar flow between two parallel plates is given by , where h is the distance separating the plates and the origin is placed midway between the plates. Consider a flow of water with viscosity . Determine the shear stress on the upper plate. (answer A) (A)- (B) - (C) (D)- 9. Consider the flow field given by ⃗ ̂ ̂ ̂, determine the acceleration of a fluid particle at point (x, y, z)=(1, 2, 3). (answer B) (A) ̂+ ̂+ ̂ (B) ̂+ ̂+ ̂ (C) ̂+ ̂+ ̂ (D) ̂+ ̂+ ̂ 10. A horizontal conveyor belt moving at speed receives sand from a hopper. The sand falls vertically from the hopper to the belt at a speed of and a flow rate of ̇ . The conveyor belt is initially empty but begins to fill with sand. If friction in the drive system and rollers is negligible, find the tension required to pull the belt while the conveyor is filling. (answer C) (A) ̇ (B) ̇ (C) ̇ (D) ̇ II. (8 point) A double-cone viscometer shown on the right is an instrument used to measure fluid viscosity. It consists of two identical cones with a very obtuse angle. The bottom cone is being held still, while the top cone rotates at constant angular velocity of . The liquid to be tested fills the narrow gap formed by the cones. 1. (4 pts) Prove that the deformation rate of the liquid is constant for the given cone angle and angular velocity. 2. (4 pts) Evaluate the torque required to hold the bottom cone still. (The given solution is for a similar problem, but not exactly the same. Revision is needed.) EML 3701 Final Exam NAME___________________________________ page 6 III. (6 point) The water flow rate through the siphon is 5 L/s, its temperature is 20 , and the pipe diameter is 25 mm. Compute the maximum allowable height, h, so that the pressure at point A is above the vapor pressure of the water .The density of water is 999 kg/m3 [Show More]

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