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- Fluid Mechanics and Hydraulic Machines - FMHM
- 2018
- PYQ
**Biju Patnaik University of Technology BPUT - BPUT**- Mechanical Engineering
- B.Tech
**6516 Views**- 289 Offline Downloads
- Uploaded 6 months ago

Registration No : Total Number of Pages : 03 B.Tech. PME4G001 4th Semester Regular / Back Examination 2017-18 FLUID MECHANICS & HYDRAULICS MACHINES BRANCH : MECH Time : 3 Hours Max Marks : 100 Q.CODE : C1164 Answer Part-A which is compulsory and any four from Part-B. The figures in the right hand margin indicate marks. Answer all parts of a question at a place. Part – A (Answer all the questions) Answer the following questions : multiple type or dash fill up type : Q1 a) b) c) d) e) f) g) h) i) j) Q2 Fluids which don’t follow the linear relationship between shear stress and rate of deformation are termed as………………fluids ……….is a phenomenon by which a liquid rises into a thin glass tube above or below its general level. The manometers are suitable for comparatively……….pressure. The point of application of the total pressure on the surface is…….. The magnitude of the buoyant force can be determined by…….principle. The path followed by fluid particle in motion is called a……………. The co-efficient of discharge of an orifice meter is…………….that of a venturimeter. Darcy-Weisbach equation is used to find the loss of head due to……. A Kaplan turbine is……..type of turbine. In a centrifugal pump, the regulating valve is provided on……. d) e) f) Answer the following questions : Short answer type : What is the relation between kinematic viscosity and dynamic viscosity? What are their units? What is the relation between gauge pressure, vacuum pressure and absolute pressure? What are the condition of equilibrium of a floating body and sub-merged body? Differentiate between stream function and velocity potential function. What is the difference between pitot tube and pitot static tube? What is cavitation and when does it occur? g) h) i) Write Bernoulli’s equation for real fluid. Define negative slip and percentage of slip of a reciprocating pump. What do you mean by governing of a turbine? j) Define indicater diagram. Draw the diagram after consideration of the effect of the acceleration and friction in suction and delivery pipes. a) b) c) (2 x 10) (2 x 10)

Part – B (Answer any four questions) Q3 Q4 Q5 Q6 a) Two large plane surfaces are 2.4 cm apart. The space between the surfaces is filled with glycerine. What force is required to drag a very thin plate of surface area 0.5 square meter between the two large plane surfaces at a speed of 0.6 m/s, if: (i) the thin plate is in the middle of the two plane surfaces, and (ii) the thin plate is at a distance of 0.8 cm from one of the plane surfaces? Take the dyanamic viscosity of glycerine = 8.10x10-1N s/m2. (10) b) State and prove the Pascal’s Law. (5) a) A cubical tank has sides of 1.5 m. It contains water for the lower 0.6 m depth. The upper remaining part is filled with oil of specific gravity 0.9.Calculate for one vertical side of the tank: Total pressure, and Position of centre of pressure. (10) b) A rectangular pontoon 8.0 m long, 7 m broad and 3.0 deep weighs 588.6 kN. It carries on its upper deck an empty boiler of 4.0 m diameter weighing 392.4 kN. The centre of gravity of the boiler and the pontoon are at their respective centres along a vertical line. Find the metacentric height. Weight density of sea water is 10104 N/m3. (5) a) Find the convective acceleration at the middle of a pipe which converges uniformly from 0.6 m diameter to 0.3 m diameter over 3 m length. The rate of flow is 40 lit/s. If the rate of flow changes uniformly from 40 lit/s to 80 lit/s in 40 seconds, find the total acceleration at the middle of the pipe at 20th second. (10) b) In a two-dimensional incompressible flow, the fluid velocity components are given by u = x-4y and v = -y-4x, Show that velocity potential exists and determine its form. Find also the stream function. (5) a) A horizontal pipe line 40 m long is connected to a water tank at one end and discharges freely into the atmosphere at the other end. For the first 25 m of its length from the tank, the pipe is 150 mm diameter and its diameter is suddenly enlarged to 300 mm. The height of water level in the tank is 8 m above the center of the pipe. Considering all losses of head which occur, determine the rate of flow. Take f = 0.01 for both sections of the pipe and also draw Hydraulic gradient line (H.G.L) and Total energy line(T.E.L). (10) b) Find the discharge of water flowing through a pipe 30 cm diameter placed in an inclined position where a venturimeter is inserted, having a throat diameter of 15 cm. The difference of pressure between the main and throat is measured by a liquid of specific gravity 0.6 in an inverted U-tube which gives a reading of 30 cm. The loss of head between the main and throat is 0.2 times the kinetic head of the pipe. (5)

Q7 Q8 Q9 a) A Pelton wheel is working under a gross head of 400 m. The water is supplied through penstock of diameter 1m and length 4km from reservoir to the Pelton wheel. The co-efficient of friction for the penstock is given as 0.008. The jet of water of diameter 150 mm strikes the buckets of the wheel and gets deflected through an angle of 1650.The relative velocity of water at outlet is reduced by 15% due to friction between inside surface of the bucket and water. If the velocity of the bucket is 0.45 times the jet velocity at inlet and mechanical efficiency as 85% determine: (i) Power given to the runner, (ii) Shaft Power (iii) Hydraulic efficiency (iv) Overall efficiency (10) b) Obtain an expression for the work done per second by water on the runner of a Pelton wheel. And also derive an expression for maximum efficiency of the Pelton wheel giving the relationship between the jet speed and bucket speed. (5) a) An inward flow reaction turbine has an external diameter of 1 m and its breadth at an inlet is 200 mm. If the velocity of flow at inlet is 1.5 m/s, find the mass of water passing through the turbine per second. Assume 15% of the area of flow is blocked by blade thickness. If the speed of the runner is 200 r.p.m. and guide blades make an angle of 150 to the wheel tangent, draw the inlet velocity triangle diagram and find: (i) The runner vane angle at inlet, (ii) Velocity of wheel at inlet, (iii) The absolute velocity of water leaving the guide vanes, (iv) Relative velocity of water entering the runner blade and (v) Hydraulic efficiency. (10) b) Define the specific speed of a turbine. Derive an expression for specific speed. What is the significance of the specific speed? (5) a) A single acting reciprocating pump has a plunger of 100 mm diameter and a stroke length 200 mm. The centre of pump is 3 m above the water level in the sump and 20 m below the water level in a tank to which water is delivered by the pump. The diameter and length of suction pipe are 50 mm and 5 m while of the delivery pipe are 40mm and 30 m respectively. Determine the maximum speed at which the pump may be run without separation, if separation occurs at 7.3575 N/cm2 below the atmospheric pressure. Take atmospheric pressure head = 10.3 m of water. (10) b) Draw and discuss the Main characteristic curves and the operating characteristic curves of a centrifugal pump? (5)

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