Download GTU B.Tech 2020 Winter 5th Sem 3150102 Fundamentals Of Turbomachines Question Paper

Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Winter 5th Sem 3150102 Fundamentals Of Turbomachines Previous Question Paper

Seat No.: ________
Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE- SEMESTER?V (NEW) EXAMINATION ? WINTER 2020
Subject Code:3150102 Date:29/01/2021
Subject Name:Fundamentals of Turbomachines
Time:10:30 AM TO 12:30 PM Total Marks: 56
Instructions:
1. Attempt any FOUR questions out of EIGHT questions.

2. Make suitable assumptions wherever necessary.

3. Figures to the right indicate full marks.


MARKS
Q.1 (a) What's is mean by turbo machine
03

(b) Discuss choking in turbo machines
04

(c) Derive Euler's energy equation for turbo machine
07
Q.2 (a) Define Degree of reaction, flow coefficient and loading
03
coefficient

(b) Explain over expansion and under expansion
04

(c) Draw velocity triangle for an axial turbine stage
07

Q.3 (a) What do you understand by The bypass ratio of a turbofan
03
engine

(b) Draw the pressure and velocity variation along the length of
04
axial turbine

(c) Explain Surge and stall in compressor. Also draw surge line by
07
drawing neat sketch

Q.4 (a) Why diameter of compressor is decreasing along the length
03

(b) List the losses in centrifugal compressor
04

(c) A single stage gas turbine operates at its design condition with
07
an axial absolute flow at entry and exit from the stage. The
absolute flow angle at the nozzle exit is 70o . At stage entry, the
total pressure and temperature are 311 kPa and 850oC
respectively. The exhaust static pressure is 100 kPa, the total to
static efficiency is 0.87 and mean blade speed is 500 m/s.
Assuming constant axial velocity through the stage, determine
(a) the specific work done (b) the Mach number leaving the
nozzle (c) the axial velocity (d) total to total efficiency (e) stage
reaction

Q.5 (a) Explain difference in multi spool and multi stage
03

(b) Why centrifugal compressors have volute diffuser?
04

(c) Draw velocity triangles for forward, backward and radial tipped
07
centrifugal compressor.

Q.6 (a) Difference between rotor blade and stator blade.
03

(b) Why multistage of centrifugal compressor is difficult
04

(c) Air at a temperature of 290K enters a ten stage axial flow
07
compressor at the rate of 3kg/s. the pressure ratio is 6.5 and the
efficiency is 90%, the compression process being adiabatic, the
compressor has symmetrical blades. The axial velocity of
110m/s is uniform across the stage and the mean blade speed of
each stage is 180m/s. determine the direction of the air at entry
1

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to and exit from the rotor and the stator blades and also the
power given to the ai

Q.7 (a) Enlist the cooling technique used for gas turbine blades
03

(b) Write a short note on stall propagation in a compressor blade
04
row

(c) Draw h-s diagram for an axial turbine stage.
07
Q.8 (a) Enlist classification of turbo machines.
03
(b) Write difference between fan, blower and compressor
04
(c) Draw stodola's model of flow with slip and Write an equation of
07
Balje's formula
2

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