First two units

Assignment 1 19MEB 201 Fluid Mechanics and Machineries 3rd Semester Mechanical Engineering “B” sec. Submit on 30th Oct 2023 Portion: Unit 1 and 2 Faculty i/c: C.SenthilKumar, ASP/Mech. Unit 1 1) Calculate the capillary effect in millimeters in a glass tu be of 4 mm diameter, when immersed in (i) water and (ii) mercury. The temperature of the liquid is 200 C and the values of the surface tension of water and the mercury at 200 C in contact with air are 0.073575 N/m and 0.51 N/m respectively. The angle of contact for water is zero and that for mercury is 1300. Take density of water at 200 C as equal to 998kg/m3. 2) A 30 cm diameter pipe, conveying water, branches into two pipes of diameters 20 cm and 15 cm respectively. If the average velocity in the 30 cm diameter pipe is 2.5 m/sec. Find the discharge in this pipe. Also determine the velocity in 1 5 cm pipe if the average velocity in 20 cm diameter pipe is 2 m/sec. 3) The dynamic viscosity of oil, used for lubrication between a shaft and sleeve is 8 poise. The shaft is of diameter 0.6 m and rotates at 195 r.p.m. Calculate the power lost in the bearing for a sleeve length of 95 mm. The thickness of the oil film is 2.5 mm. 4) Calculate the dynamic viscosity of an oil, which is used for lubrication between as square plate of size 0.8m×0.8m and an inclined plane with angle of inclination 30° as shown in fig. The weight of the square plate is 300N and it slides down the inclined plane with a uniform velocity of 0.3m/s. The thickness of oil film is 1.5mm. 5) The water is flowing through a taper pipe of length 100 mm having diameter 600 mm at the upper end and 300 mm at the lower end, at the rate of 50 lit/sec. The pipe has a slope of 1 in 30. Find the pressure at the lower end if the pressure at the higher level is 19.62 N/cm2. Unit 2 1. The velocity distribution in the boundary layer is given by u/U =y/δ, where u is the velocity at a distance y from the plate u=U at y =δ, δ being boundary layer thickness. Find the displacement thickness, momentum thickness and energy thickness. (16) [APR’10/13b] 2. The velocity of water in a pipe 200mm diameter is 5m/s. The length of the pipe is 50m. Find the loss of head due to friction, if f= 0.08. (4) [NOV/DEC ‘2005/14b(ii)] 3. The rate of flow of water through a horizontal pipe is 0.25 m3/sec.The diameter of the pipe which is 20 cm is suddenly enlarged to 40 cm. The pressure intensity in the smaller pipe is 772 N/cm2. Determine : Loss of head due to sudden enlargement, Pressure intensity in larger pipe, Power loss due to enlargement. (9) [JUNE ‘09/13a(i)] 4. An oil of sp.gravity 0.7 is flowing through a pipe of diameter 30 cm at the rate of 500 litres/sec. Find the head lost due to friction and power required to maintain the flow for a length of 1000 m. Take υ= 0.29 stokes. (8) [JUNE ‘09/13b(ii)]