BH40A0801 Turbomachinery
Lecture 1
Jari Backman
Contents of the course
1.
2.
3.
Recap of thermodynamics with focus on turbomachinery
Gas turbines
Jet Engines
This course uses Moodle, where you can fin
BH40A0081Turbomachinery
Tips for the lesson 1 exercises
Exercise 1
a) The relation of the total temperature and the static temperature
b) Dynamic pressure
Ideal gas law
pv = RT
Exercise 2
a) Compressi
BH40A0081Turbomachinery
TDSection
Solutions for lesson 1 exercises
Exercise 1:
absolute velocity of the flow [m/s]
c
Now
temperature
specific heat capacity at a mean temperature [J/kgK]
and . Because
BH40A0081Turbomachinery
TDSection
Exercise 1.
In the inlet of a radial compressor the velocity of air c1 is 70 m/s and the measured total
temperature is 20 C, and the pressure in the room is 101 kPa.
BH40A0081Turbomachinery
SectionTD
Exercise 1
a) Compressor
p1 = 100 kPa
pressure before the compressor
T1 = 25 C = 298, 15 K
temperature before the compressor
p = 0,90
polytropic efficiency for the co
BH40A0081Turbomachinery
SectionTD
Exercise 1
a) Dry air coming to a radial compressor has a pressure of p1 = 100 kPa and a
temperature of T1 = 25 C. The polytropic efficiency of the compressor is 0,90
BH40A0801 Turbomachinery
Section GT
Lesson
Jari Backman
GT Lesson objectives

I know the differences with various gas turbine cycles
I know what kind of a gas turbine is suited for each use
I know th
BH40A0081 Turbomachinery
Section JE
Exercise 11
The needed values can be calculated with the polytropic equation and the power
equation. You just must remember, that the bypass ratio means high pressu
BH40A0081 Turbomachinery
Section JE
Exercise 11
An airplane is staying still on sea level (ambient pressure pt1 = 1,0 bar and
ambient temperature is Tt1 = 288 K.) The fan of the engine is rotated by l
BH40A0080 Turbomachinery
Lesson 3
Exercise 1
Calculate the thrust generated by a jet engine. The altitude is 1000 m and the velocity of the
plane is 270 m/s. We know the following of the jet engine:
P
BH40A0081 Turbomachinery
Section JE
Exercise 11
Lets calculate the engine by using the notation in the picture
Fan
High pressure compressor
High pressure turbine
High pressure turbine rotates the high
BH40A0080 Turbomachinery
Lesson 3
Exercise 1
Lets check the pressure and temperature at the altitude of 1000 m
pa = 89,85 kPa
Ta = 281,65 K
Lets calculate the total temperature and pressure after the
BH40A0080 Turbomachinery
Lesson 1
Solutions for lesson 2 exercises
Exercise 7
Total temperatures:
before compressor Tt1 = 20 C = 293 K
after compressor Tt2 = 427 C = 700 K
before turbine Tt3 = 1227 C
BH40A0080 Turbomachinery
Lesson 1
Tips for lesson 2 exercises
Exercise 7:
The purpose of this exercise in
a) is to calculate the enthalpy with the heat capacity and the temperature differences, not
by
BH40A0080 Turbomachinery
Lesson 1
Exercise 1
Total temperatures:
Before the compressor
Tt1 = 15 C = 288 K
Before the turbine
Tt3 = 1227 C = 1500 K
Pressure ratio in the compressor and in the turbine
p
BH40A0080 Turbomachinery
Lesson 1
Exercise 7
We have an open cycle gas turbine process without a recuperator. The pressure ratio of the
compressor is 20,0. The total temperature after the compressor i
BH40A0080 Turbomachinery
Lesson 1
Exercise 1
Open gas turbine cycle without recuperator. The pressure ratio of the compressor and the
turbine is 16. Total temperature before the turbine is 1227 C, the