SPPU Question Papers
Class: TE Mechanical (2015 Course)
Subject: Turbo Machines
Unit I: Introduction to Turbo Machinery
March 2015
Q.
1. a) A 6 mm diameter jet of water having a velocity of 30 m/s strikes a flat
plate, the normal from which is inclined at 33° to the axis of the jet. Find
the force exerted by jet on plate in the direction of motion of plate when (i)
the plate is stationary and (ii) the plate is moving with a velocity of 18m/s
away from the jet. Determine the power and efficiency of the jet when the plate
is moving. [6 marks]
May 2015
Q.
1. a) A jet of water moving with ‘V’ m/s strikes at center of a curved vane
which is moving with ‘u’ m/s. If the outgoing jet makes an angle θ with the
incoming jet, prove that: [6 marks]
i)
Maximum efficiency = ηmax
=
(1 + cosθ)
ii) Blade speed u = V/3
December 2015
None question asked.
March 2016
Q.
2. a) A jet of water having a velocity of 40 m/s strikes a curved vane, which
is moving with a velocity of 20 m/s. The jet makes an angle of 30° with the
direction of vane at inlet and leaves at an angle of 90° to the direction of
vane at outlet. Determine vane angles at inlet and outlet so that water enters
& leaves the vane without shock. [6
marks]
May 2016
None question asked.
December 2016
Q. 1. b) Show that the
efficiency of a free jet striking normally on a series of flat plates mounted
on the periphery of a wheel can never exceed 50 %. [4 marks]
March 2017
Q. 1. a) Derive the
relation for force exerted by jet of water on inclined fixed plate in the
direction of jet. [4 marks]
OR
Q. 2. a) Define turbo machine. Explain salient
features of turbo machines. [4 marks]
Q. 2. b) A 7.5 cm
diameter of jet having velocity of 30 m/s strikes a flat plate, the normal of
which is inclined at 45° to axis of jet. Find the normal force exerted on the
plate, work done and efficiency of the system. [6 marks]
May 2017 (2012 Pattern)
Q. 1. a) Prove that the
force exerted by jet of water on semi-circular curve plate is two times the
force exerted by jet of water on flat vertical plate. [4 marks]
August 2017 (2015 Pattern – Insem.)
Q. 1. a) A 7.5 cm
diameter jet having velocity of 12 m/s impinges in a smooth plate at an angle
of 60° to the normal to the plate. What will be the force when: [6 marks]
i) The plate is
stationary
ii) The plate is moving
in the direction of jet at 6 m/s
iii) Work done per
second in each case
Q. 1. b) Derive the
expression for the force exerted by a jet of water on an inclined fixed plate in
the direction of jet. [4 marks]
OR
Q. 2. a) Derive the
expression of work done per second for symmetrical moving curved vane with
tangential entry of jet. [4 marks]
Q. 2. b) A circular jet
of water having velocity of 60 m/s impinges tangentially on a series of curved
vanes moving uniformly at 25 m/s. The jet makes an angle of 30° with the
direction of motion of the vanes. Relative to a vane, the jet turns through an
angle of 100° as it flows over the vane. The flow speed along the vane drops by
15 % due to frictional loss. Draw neat inlet and outlet velocity triangles
showing all the relevant details and determine: [6 marks]
i) Vane tip angles at
inlet and outlet for the smooth flow
ii) Absolute velocity
of water leaving the vanes
December 2017 (2015 Pattern)
Q. 1. a) Show that the
ratio of flow rate, Q1/Q2 = (1+cosθ)/ (1-cosθ) for the impact of jet on
stationary flat plate inclined at θ° to the direction of the horizontal jet,
where Q1 = upward directed flow rate and Q2 = downward directed flow rate. [6 marks]
December 2017 (2012 Pattern)
Q. 2. b) A 7.5 cm
diameter jet having velocity of 12 m/s impinges in a smooth plate at an angle of
60° to the normal to the plate. What will be the force when: [6 marks]
i) The plate is
stationary
ii) The plate is moving
in the direction of jet at 6 m/s
iii) Work done per
second in each case
May 2018
Q. 1. a) Derive an
expression for the force exerted by the jet of water on the fixed curved plate,
jet strikes at center of the curved plate at normally. [4 marks]
August 2018
Q.
1. a) A 2.5 cm diameter jet strikes without shock on a series of vanes. The jet
velocity is 60 m/s and the vanes move with velocity of 14 m/s in the same
direction as the jet. The jet is deflected through an angle of 150° and the
relative velocity reduces by 10 % as water flows across the vanes. Calculate
the power developed and efficiency. [6
marks]
Q. 1. b) Classify turbo
machines based on any four criteria with examples. [4 marks]
OR
Q.
2. a) A square plate weighing 115 N and of uniform thickness and 30 cm edge is
hung so that a horizontal jet 2 cm diameter and having a velocity of 15 m/s
impinges on the plate. The centerline of the jet is 15 cm below the upper edge
of the plate and when the plate is vertical and 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 the plate vertical. If the plate is allowed to swing
freely, find the inclination to the vertical. [6 marks]
Q. 2. b) Write a note
on any four types of losses in turbo machines. [4 marks]
December 2018
Q. 1. a) A jet has a direct
impact on a series of flat plate vanes mounted over the periphery of a large
wheel. Determine the force of impact and the work done per second. [4 marks]
May 2019
Q. 1. a) Derive the
expression for the force exerted by a jet of water on a hinged plate in the
direction of jet. [4 marks]
No comments:
Post a Comment
Post Your Opinion / Feedback / Query