Abstract

In this paper, we present an approach for teaching turbojet engine performance that combines mathematical analysis with the use of performance software to provide students with a comprehensive and in-depth understanding of engine performance and how it is affected by design parameter choices. In the first part, we present the derivation of a universally valid analytical model for turbojet engine cycle design, which is the basis of the propulsion courses at RWTH Aachen University. The analytical model allows for the calculation of specific thrust as well as thermal and propulsive efficiencies as a function of pressure ratios and burner exit temperature. These are all expressed as differentiable functions. Their mathematical extremes form a basis for examining the intricate relationships in turbojet engine design. In the second part, we move from theory to practice. We utilize the GasTurb software, computing turbojet engine cycles for a wide range of cycle design parameters. The analytically derived trends are validated and errors introduced by simplifications are assessed. Differences between the analytical approach and software-based performance simulations of real engines, like temperature-dependent gas properties and secondary air systems, are emphasized and discussed, thus providing a bridge to real-world applications. In summary, this paper describes a two-step approach to teaching turbojet engine design using analytics and performance software. Each approach alone can be used to enrich and extend existing performance courses. Combining the approaches has significant benefits, improving understanding and inspiring students to pursue further research in the field of propulsion.

References

1.
Reissner
,
H.
,
1947
, “
Systematic Analysis of Thermal Turbojet Propulsion
,”
J. Aeronaut. Sci.
,
14
(
4
), pp.
197
210
.10.2514/8.1321
2.
Zucrow
,
M. J.
,
1948
,
Principles of Jet Propulsion and Gas Turbines
,
Wiley
,
New York
.
3.
Hughes
,
R. F.
,
1951
, “
Analytical Performance Study of Turbojet Cycle With Nearly Ideal Component Efficiencies
,”
Engineer’s thesis
,
California Institute of Technology, Pasadena, CA
.https://thesis.library.caltech.edu/1031/
4.
Oates
,
G. C.
,
1997
,
Aerothermodynamics of Gas Turbine and Rocket Propulsion (AIAA Education Series)
, 3rd ed.,
AIAA
, Reston, VA.
5.
Kerrebrock
,
J. L.
,
1992
,
Aircraft Engines and Gas Turbines
, 2nd ed.,
MIT Press
, Cambridge, MA.
6.
Mattingly
,
J. D.
,
1996
,
Elements of Gas Turbine Propulsion
, Vol.
1
,
McGraw-Hill
,
New York
.
7.
GasTurb GmbH,
2023
, “
GasTurb 14—Gas Turbine Performance Software
,”
GasTurb GmbH
,
Aachen, Germany
, accessed Dec. 4, 2023, www.gasturb.com
8.
Aus der Wiesche
,
S.
,
2014
, “
Development of a Course on Gas and Steam Turbines Supported by Cost-Efficient Turbomachinery Experiments
,”
ASME
Paper No. GT2014-25076.10.1115/GT2014-25076
9.
Byerley
,
A. R.
,
Rouser
,
K. P.
, and
O’Dowd
,
D. O.
,
2017
, “
Exploring GasTurb 12 for Supplementary Use on an Introductory Propulsion Design Project
,”
ASME
Paper No. GT2017-63465.10.1115/GT2017-63465
10.
Piqueras
,
P.
,
De la Morena
,
J.
,
Bares
,
P.
, and
Sanchis
,
E. J.
,
2021
, “
Case Study-Based Learning Using a Computational Tool to Improve the Understanding of the Jet Engine Cycle for Aerospace Engineering Degree Students
,”
Comput. Appl. Eng. Educ.
,
29
(
6
), pp.
1857
1870
.10.1002/cae.22427
11.
NLR—Royal Netherlands Aerospace Centre
,
2023
, “
GSP Gas Turbine Simulation Program
,” NLR—Royal Netherlands Aerospace Centre, Amsterdam, The Netherlands, accessed Dec. 8, 2023, www.gspteam.com
12.
EA International
,
2023
, “
EcosimPro—PROOSIS—Modelling and Simulation Toolkits and Services
,” EA International, Madrid, Spain, accessed Dec. 8, 2023, www.ecosimpro.com
13.
Southwest Research Institute
,
2023
, “
Numerical Propulsion System Simulation (NPSS)
,” Southwest Research Institute, San Antonio, TX, accessed Dec. 8, 2023, www.swri.org/consortia/numerical-propulsion-system-simulation-npss
14.
Hendricks
,
E. S.
, and
Gray
,
J. S.
,
2019
, “
pyCycle: A Tool for Efficient Optimization of Gas Turbine Engine Cycles
,”
Aerospace
,
6
(
8
), p.
87
.10.3390/aerospace6080087
15.
GasTurb GmbH
,
2023
, “
GasTurb 14: Design and Off-Design Performance of Gas Turbines
,” User Manual,
GasTurb GmbH
,
Aachen, Germany
.
16.
Gordon
,
S.
, and
McBride
,
B. J.
,
1994
, “
Computer Program for Calculation of Complex Chemical Equilibrium Compositions and Applications. Part 1: Analysis
,” NASA Lewis Research Center, Cleveland, OH, Report No.
NASA RP 1311
.https://ntrs.nasa.gov/citations/19950013764
17.
Kurzke
,
J.
,
2007
, “
About Simplifications in Gas Turbine Performance Calculations
,”
ASME
Paper No. GT2007-27620.10.1115/GT2007-27620
You do not currently have access to this content.