Rr220303-mechanics Of Fluids 2-2 Rr

RR

Code No: RR220303

II B.Tech. II Semester(RR) Supplementary Examinations, April/May 2009 MECHANICS OF FLUIDS (Mechanical Engineering)

Time: 3 hours

Max Marks: 80 Answer any FIVE questions All questions carry equal marks ?????

1. (a) What is meant by Newtonian and Non Newtonian fluids. Explain with the help of examples. (b) A circular gate in a vertical wall has a diameter of 4m. The water surface on the upstream side is 8m above the top of the gate and on the down stream side 1m above the top of the gate. Find the forces acting on the two sides of the gate and the resultant force acting on the gate and its location. 2. (a) Define equipotential line and a line of constant stream function, show that these lines intersect orthogonally. (b) Given that U=x2 -y2 and V= -2xy. Check whether stream function exists. If so determine the stream function and potential function for the flow. 3. (a) Derive Euler’s equation of motion for a fluid flow. (b) A jet of water issues from 20mm dia fire hose at the end of which a 5.0 mm diameter nozzle is fixed. If pressure at inlet of the nozzle is 200 KN/m2 , determine force exerted by nozzle on the flow 4. (a) Give four examples in every day life where separation takes place. Draw flow pattern in each case. (b) A jet plane, which weighs 30KW and has a wing area of 20m2 flies at a velocity of 1000 Km/hr when the engine delivers 7350KW, 65% of the power is used to overcome the drag resistance of the wing. Calculate the coefficient of lift and drag for the wing. The mass density of air is 1.2Kg/m3 . 5. (a) What is the relation between pressure and density of a compressible fluid for i. Isothermal ii. Adiabatic process. (b) Air, thermodynamic state of which given by pressure P=230KN/m2 and temperature=300K is moving at a velocity V= 250m/s. Calculate the stagnation pressure if i. Compressibility is neglected. ii. Compressibility account for. 6. (a) Obtain an expression for the head loss in laminar flow in a circular pipe. Also write down the equation for head loss due to laminar flow between parallel plates and for flow down an inclined plane. Give Reynolds numbers upto which these equations are valid. (b) An oil of specific gravity 0.9 flow at a rate of 0.2m3 /s through a horizontal pipe of 7.5cm diameter. The pressure drop is 400KN/m2 over 300m length of pipe. Find the viscosity of the oil. 7. (a) What is syphon? On what principle it works? Under what conditions it would stop functioning. (b) A horizontal pipe of diameter 50cm is suddenly contracted to a diameter of 25cm. The pressure intensities in the large and smaller pipe are given as 13.74 N/cm2 and 11.77 N/cm2 respectively. If the rate of flow of water is 300lit/sec, find the value of coefficient of contraction. 8. (a) Explain venturimeter in detail with diagram. Also derive as expression for finding out the actual discharge from a given venturimeter. (b) What is the purpose of hot wire Anenometer? Explain the working procedure. ?????