JNTU PAPERS

JNTU, B.Tech,I-Semester

Hydraulics And Hydraulic Machinery

November 2008

(Electrical & Electronic Engineering)

SET-2

1. (a) Obtain an expression for excess pressure in a free jet.

(b) A body weighing 440 N with a surface area of 0.09m2 slides down lubricated

inclined plane making 300 with horizontal. For dynamic viscosity of 0.1Ns/m2 and body velocity of 3 m/s, determine the lubricant film thickness.

2. (a) Briefly explain the classification of flows.

(b) What type of acceleration is to be expected if

i. Streamlines are parallel and equidistant

ii. Streamlines are straight and converging

iii. Streamlines are curved but equispaced

iv. Streamlines are curved and converging.

3. 0.07m3/s of water flows through a pipe of 15 cm diameter which suddenly enlarges

to 30 cm, and the larger diameter is at the lower end. The pressure gauge at a point 50 cm above the section of enlargement shows a pressure of 196.2kN/m2. Determine the pressure at another point 50 cm, below the section of enlargement, if the flow is downward and the pipe is vertical.

4. In a smooth pipe of diameter 0.5m and length 1000m, water is flowing at the rate of 0.05m3/s. Assuming the Kinematic viscosity of water as 0.02 stokes, find:

(a) Head lost due to friction

(b) Wall shear stress and

(c) Centre -line velocity.

5. (a) Explain the working principle of a pitot-static tube with a neat sketch?

(b) Bring out clearly the differences between venturi meter and orifice meter.

6. A square plate weighing 115N and of uniform thickness and 30 cm edge is hung so

that horizontal jet 2 cm diameter and having a velocity of 15 m/s impinges on the plate. The center line of the jet is 15 cm below the upper edge of the plate, and when the plate is vertical the jet strikes the plate normally and at its center. Find what force must be applied at the lower edge of the plate in order to keep plate vertical.If the plate is allowed to swing freely, find the inclination to vertical which the plate will assume under the action of jet.

7. A Reaction turbine works at 450 RPM under a head of 120m. Its diameter at

inlet is 120 cm and the flow area is 0.4 m2. The angles made by the absolute and relative velocities at inlet are 200 and 600 respectively with the tangential velocity.

Determine:

(a) The volume flow rate,

(b) The power developed and

(c) The efficiency. Assume whirl at outlet to be zero.

8. (a) Define Specific speed of a Centrifugal pump and obtain the equation for it.

(b) Explain the main characteristic curves of a Centrifugal pump.