* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

# Download AMEE 202 Midterm S14_1 Group 2

Survey

Document related concepts

Accretion disk wikipedia , lookup

Wind-turbine aerodynamics wikipedia , lookup

Airy wave theory wikipedia , lookup

Fluid thread breakup wikipedia , lookup

Lift (force) wikipedia , lookup

Hydraulic cylinder wikipedia , lookup

Flow measurement wikipedia , lookup

Compressible flow wikipedia , lookup

Computational fluid dynamics wikipedia , lookup

Hydraulic machinery wikipedia , lookup

Flow conditioning wikipedia , lookup

Navier–Stokes equations wikipedia , lookup

Derivation of the Navier–Stokes equations wikipedia , lookup

Coandă effect wikipedia , lookup

Aerodynamics wikipedia , lookup

Reynolds number wikipedia , lookup

Transcript

Department of Mechanical Engineering SUBJECT: AMEE 202 - FLUID MECHANICS I DATE: 8 April 14 TIME: 90 Minutes INSTRUCTIONS TO CANDIDATES: Answer all questions from Section A and two questions from Section B. All necessary work must be shown. Wherever needed: H 2O 1000 kg/m3 , H2O 1.15 10-3 Pa s, air 1.225 kg/m 3 , air 1.79 10 5 kg /(m s ) g=9.81 m/s2 , patm 1.01 105 N/m 2 , 1.0 in= 0.0254 m, 1 ft=12 in, R 286.9 J/(kg K) __________________________________________________________________ SECTION A QUESTION 1 [20 Marks] Fluid with mean velocity 5 m/s flows over a sphere to produce the flow pattern shown on the left figure. The same fluid flows over a sphere half the size of the original sphere and produces the same flow pattern (right figure). a. State whether the flow is laminar or turbulent and explain b. Determine the velocity of the fluid on the latter case. QUESTION 2 [20 Marks] The tank shown on the figure contains a liquid of density . State whether the following statements are true (T) or False (F), and give the correct answer if the latter. (Note: pg denotes gauge pressure). patm z g A z i. z h/ 2 v. ii. FR ( patm gh / 2)hb vi. iii. iv. pA pgA patm vii. pg is gauge pressure viii. The gauge pressure at the surface is patm pA gh patm The gauge pressure at the bottom is equal to gh The net force acing on the side is equal to gh 2b / 2 SECTION B QUESTION 3 [30 Marks] A hot air balloon weighs 230 kg , including the weight of the balloon, the basket and one person. If the density of the hot air inside the balloon is in 1.04 kg/ m 3 , determine the required volume of the balloon to support the weight. If the balloon had 4 a spherical shape V r 3 , what would be the required diameter? 3 in out 1.18 kg/ m 3 QUESTION 4 [30 Marks] A static thrust stand as sketched in the figure is to be designed for testing a jet engine. The following conditions are known for a typical test: i. Intake air velocity = 200 m/ s ii. Exhaust gas velocity = 500 m/ s iii. Intake cross-sectional area = 1 m 2 iv. Intake static pressure = 22.5 kP a v. Intake static temperature = 268 K vi. Exhaust density= 0.515 kg/ m 3 Estimate the mass flow rate and the volumertric flow rate at the exit. Note: the ideal gas equation of state is p R T where p is the absolute pressure. QUESTION 5 [30 Marks] The viscosity of liquids can be measured through the use of a rotating cylinder viscometer of the type illustrated in the figure. In this device the outer cylinder is fixed and the inner cylinder is rotated with an angular velocity, . The torque T required to develop is measured and the viscosity is calculated from these two measurements. If the liquid under testing is oil with 0.1 N s/m2 determine the torque developed if the inner cylinder rotates with 200 rpm, 15 cm, Ro 7 cm, Ri 6.5 cm . Neglect end effects and assume the velocity distribution in the gap is linear. a. Find the velocity of the surface of the inner cylinder b. Find the Shear Stress on the inner cylinder. c. Find the total force acting on the inner cylinder, and the Torque. T