Jawaharlal Nehru Technological University Hyderabad
Jawaharlal Nehru Technological University Hyderabad B.Tech II Year HYDRAULICS AND HYDRAULIC MACHINERY Previous Question Paper (May - 2019 - R15)
Part A is compulsory which carries 25 marks. Answer all questions in Part A. Part B consists of 5 Units. Answer any one full question from each unit. Each question carries 10 marks and may have a, b, c as sub questions.
Part A
List the applications of Hydraulic Jump.
Answer
- To dissipate excess energy of flowing water below spillways and sluice gates to prevent downstream erosion.
- To increase the depth of flow for irrigation or water distribution.
- To mix chemicals in water treatment plants.
- To increase the weight on an apron to reduce uplift pressure.
Differentiate critical, sub critical and super critical flow in a open channel.
Answer
| Flow Type | Froude Number (Fr) | Description |
|---|---|---|
| Sub-critical | Fr < 1 | Velocity is less than wave velocity; flow is tranquil. |
| Critical | Fr = 1 | Flow occurs at minimum specific energy. |
| Super-critical | Fr > 1 | Velocity is greater than wave velocity; flow is rapid. |
What are the different types of similarities?
Answer
Sign in to view the complete answer paper.
Distinguish the term model and prototype quoting with examples.
Answer
Sign in to view the complete answer paper.
Define and explain the term impact of jet.
Answer
Sign in to view the complete answer paper.
What is angular momentum principle? How it is useful in impact of jets?
Answer
Sign in to view the complete answer paper.
Write the classification of hydraulic turbine.
Answer
Sign in to view the complete answer paper.
Compare operating characteristics of impulse turbine with reaction turbine.
Answer
Sign in to view the complete answer paper.
What is utilization factor? How it is used in hydraulic power plants.
Answer
Sign in to view the complete answer paper.
Why cavitation occurs in C.P? Explain how it can be controlled.
Answer
Sign in to view the complete answer paper.
Part B
An open channel 3 m wide rectangular in shape carries the discharge at normal depth of 1.2 m. What should be the slope of channel if the Manning’s “n” is 0.014.
Answer
Sign in to view the complete answer paper.
A wide rectangular channel carries a flow of 2.75 m3/s per meter width, the depth of flow being 1.5 m. Calculate the rise of the floor level required to produce critical flow conditions. What is the corresponding fall in surface level?
Answer
Sign in to view the complete answer paper.
Determine approximate water surface slope (m per km) at a point in a rectangular channel in which the discharge is 0.84 m3/s, the bed width is 3 m, the depth of flow is 0.75 m and the bed slope is 0.15 m per km. Assume C in Chezy’s formula as 55 and take energy coefficient alpha equal to unity.
Answer
Sign in to view the complete answer paper.
What do you mean by dimensionally homogenous equation? Give few examples.
Answer
Sign in to view the complete answer paper.
What is meant by hydraulic similarity between a model and prototype?
Answer
Sign in to view the complete answer paper.
What is kinematic similarity? What is its significance?
Answer
Sign in to view the complete answer paper.
A turbine develops 1900 KW at 500 rpm under a net head of 22 m. Its diameter is 2.5m. A model of 1:5 is tested under a head of 4 m. Estimate the size, speed, discharge and power developed by the model. Assume an efficiency of 82%.
Answer
Sign in to view the complete answer paper.
Show that the force exerted by a jet of water on an inclined fixed plate in the direction of the jet is given by
Answer
Sign in to view the complete answer paper.
A jet of water of diameter 50mm moving with a velocity of 20m/sec strikes a fixed plate in such a way that the angle between the jet and the plate is 600. Find the force exerted by the jet on the plate i) In the direction normal to the plate ii) In the direction of the jet.
Answer
Sign in to view the complete answer paper.
A water jet 20 mm in diameter and having a velocity of 90 m/s strikes series of moving blades in a wheel. The direction of the jet makes 200 with the direction of movement of the blade. The blade angle at inlet is 350. If the jet should enter the blade without striking, what should be the blade velocity? If the outlet angle of the blade is 300, determine the force on the blade. Assume that there is no friction involved in the flow over the blade.
Answer
Sign in to view the complete answer paper.
A Pelton wheel has to be designed for the following data Power to be developed = 6000 kW. Net head available = 300 m; Speed = 550 r.p.m; Ratio of jet diameter to wheel diameter = 1/10; and overall efficiency = 85%. Find the number of jets; diameter of the jet; diameter of the wheel; and the quantity of water required.
Answer
Sign in to view the complete answer paper.
A pelton wheel develops 4500 kW under a net head of 125 m while running at a speed of 200 rpm. Assuming KV = 0.98, speed ration Ku = 0.46 and overall efficiency η0=88%, the ratio of nozzle diameter to pitch circle diameter (d/D) = 1/9. Determine: (a) discharge required (b) diameter of wheel (c) the diameter and number of jets required.
Answer
Sign in to view the complete answer paper.
Explain the significance of similarity parameters in centrifugal pump.
Answer
Sign in to view the complete answer paper.
A centrifugal pump with radial inflow delivers 0.06 cumecs of water against a total head of 35 m. If the outer diameter of the impeller is 40 cm and its width at the outer periphery is 1.3 cm, find the blade angle at exit. The speed of the pump is 1200 rpm and its efficiency is 75%.
Answer
Sign in to view the complete answer paper.
The diameter and width of a centrifugal pump impeller are 50 cm and 2.5 cm. The pump runs at 1200 rpm. The suction head is 6 m and the delivery head is 40 m. The frictional drop in suction is 2 m and in the delivery 8 m. The blade angle at out let is 300. The manometric efficiency is 80% and the overall efficiency is 75%. Determine the power required to drive the pump. Also calculate the pressures at the suction and delivery side of the pump.
Answer
Sign in to view the complete answer paper.