Motivated by the long-term target settings for research and innovation in Europe and in North America, initial investigations of parallel hybrid electric power plant systems have indicated significant in-flight fuel reduction potentials for short range air transport. Based on this topology, a special variant, namely the cycle-integrated parallel hybrid (CIPH), has been investigated. In this special configuration, electric motors supplied by batteries are powering an array of compressor stages of a power plant that are mechanically decoupled from the turbine section. The potentials with regard to in-flight fuel reduction and efficiency improvement of this concept are derived for a 12-ton-helicopter accommodating 19 passengers on a 450 nm mission. For the presented CIPH concept, the axial compressor section of a baseline turboshaft (TS) delivering a maximum shaft power of 3300 kW is electrified with the help of linear electric motors (LEMs). The highest potential for this arrangement was identified in part load for moderate degrees of power hybridization—the share between installed electric power and total power—of around 20%. The first assessment has revealed that this additional degrees-of-freedom allows to almost double the overall efficiency, compared to a conventional power with same technology time horizon, and a reduction in power-specific fuel consumption (PSFC) of roughly 45%. The range capability of a hybrid-powered helicopter has been decreased by more than 50%, mainly driven by the battery mass. However, a fuel burn, and thus, in-flight CO2 reduction of more than 40% against the reference at decreased mission range have been found.

References

References
1.
ACARE
,
2012
, “
Strategic Research and Innovation Agenda—Volume 1
,”
Advisory Council for Aviation Research and innovation in Europe
,
Brussels, Belgium
.
2.
Stückl
,
S.
,
van Toor
,
J.
, and
Lobentanzer
,
H.
,
2012
, “
VOLTAIR—The All Electric Propulsion Concept Platform—A Vision for Atmospheric Friendly Flight
,”
28th International Congress of the Aeronautical Sciences
, Paper No. ICAS 2012-4.7.2.
3.
Isikveren
,
A. T.
,
Seitz
,
A.
,
Vratny
,
P. C.
,
Pornet
,
C.
,
Plötner
,
K. O.
, and
Hornung
,
M.
,
2012
, “
Conceptual Studies of Universally-Electric Systems Architectures Suitable for Transport Aircraft
,”
Deutscher Luft- und Raumfahrt Kongress 2012
, Berlin, Paper No. DLRK2012-281368.
4.
Bradley
,
M. K.
, and
Droney
,
C. K.
,
2011
, “
Subsonic Ultra Green Aircraft Research: Phase I Final Report
,” Huntington Beach, CA, Report No. NASA/CR -2011-216847.
5.
Isikveren
,
A. T.
,
Pornet
,
C.
,
Vratny
,
P. C.
, and
Schmidt
,
M.
,
2015
, “
Conceptual Studies of Future Hybrid-Electric Regional Aircraft
,”
ISABE 2015
, Paper No. ISABE-2015-20285.
6.
Pornet
,
C.
,
Gologan
,
C.
,
Vratny
,
P. C.
,
Seitz
,
A.
,
Schmitz
,
O.
,
Isikveren
,
A. T.
, and
Hornung
,
M.
,
2014
, “
Methodology for Sizing and Performance Assessment of Hybrid Energy Aircraft
,”
J. Aircr.
,
52
(
1
), pp.
1
12
.
7.
Brown
,
G. V.
,
2011
, “
Weights and Efficiencies of Electric Components of a Turboelectric Aircraft Propulsion System
,”
AIAA
Paper No. 2011-225-396.
8.
EASA
,
2012
, “
Certification Specifications for Large Rotorcraft CS-29
,”
European Aviation Safety Agency, Cologne
,
Germany
.
9.
Lorenz
,
L.
,
Seitz
,
A.
,
Kuhn
,
H.
, and
Sizmann
,
A.
,
2013
, “
Hybrid Power Trains for Future Mobility
,”
Deutscher Luft- und Raumfahrt Kongress 2013
, Paper No. DLRK2013-301316.
10.
Schmitz
,
O.
,
2012
, “
Fahrzeugtriebwerk, Fahrzeug mit diesem Fahrzeugtriebwerk und Verfahren zum Betrieb dieses Fahrzeugtriebswerkes
,” Patent No. DE102012015104.
11.
Vratny
,
P. C.
,
Kuhn
,
H.
, and
Hornung
,
M.
,
2015
, “
Influences of Voltage Variations on Electric Power Architectures for Hybrid Energy Aircraft
,”
Deutscher Luft- und Raumfahrtkongress 2015
, Paper No. DLRK2015-370198.
12.
Vratny
,
P. C.
,
Gologan
,
C.
,
Pornet
,
C.
,
Isikveren
,
A. T.
, and
Hornung
,
M.
,
2013
, “
Battery Pack Modeling Methods for Universally-Electric Aircraft
,”
CEAS 2013
, pp.
525
535
.
13.
Vratny
,
P. C.
,
2012
,
A Battery Powered Transport Aircraft
,
AV Akademikerverlag
,
Saarbrücken, Germany
.
14.
Shahat El
,
A.
,
Keyhani
,
A.
, and
Shewy El
,
H.
,
2010
, “
Sizing a High Speed PM Generator for Green Energy Applications
,”
J. Electr. Syst.
,
6
(
4
), pp.
501
516
.
15.
Eichenberg
,
D. J.
,
2006
, “
Development of a 32 Inch Diameter Levitated Ducted Fan Conceptual Design
,” Glenn Research Center, Cleveland, OH,
Technical Report No. NASA/TM-2006-214481
.
16.
Pyrhönen
,
J.
,
Jokinen
,
T.
, and
Hrabovocá
,
V.
,
2008
,
Design of Rotating Electrical Machines
,
Wiley
,
Chichester, UK
.
17.
Steiner
,
H.
,
Seitz
,
A.
,
Wieczorek
,
K.
,
Plötner
,
K.
,
Isikveren
,
A. T.
, and
Hornung
,
M.
,
2012
, “
Multi-Disciplinary Design and Feasibility Study of Distributed Propulsion Systems
,”
28th International Congress of the Aeronautical Sciences
, Paper No. ICAS 2012-1.7.5.
18.
Lanchester
,
F. W.
,
1941
, “
Contra-Props
,”
Flight
, pp.
418
419
.
19.
Stewart
,
W. L.
,
1955
, “
Investigation of Rotating Components of Counterrotating Two-Spool Engines
,” National Advisory Committee for Aeronautics, Washington,
Technical Report No. NACA-RM-E54J13
.
20.
Alexiou
,
A.
,
Roumeliotis
,
I.
,
Aretakis
,
N.
,
Tsalavoutas
,
A.
, and
Mathioudakis
,
K.
,
2012
, “
Modeling Contra-Rotating Turbomachinery Components for Engine Performance Simulations: The Geared Turbofan With Contra-Rotating Core Case
,”
ASME J. Eng. Gas Turbines Power
,
134
(
11
), p.
111701
.
21.
Lewis
,
R. I.
,
1996
,
Turbomachinery Performance Analysis
,
Elsevier Science and Technology Books
,
London
.
22.
Seitz
,
A.
,
2012
, “
Advanced Methods for Propulsion System Integration in Aircraft Conceptual Design
,”
Ph.D. thesis
, Technische Universität München, München, Germany.
23.
Kurzke
,
J.
,
2007
, “
GasTurb 11—Design and Off-Design Performance of Gas Turbines
,”
GasTurb GmbH
,
Germany
.
24.
Shamiyeh
,
M.
,
2015
, “
Conceptual Design of a Hybrid Electric Rotorcraft
,” Master thesis, Technische Universität München, München, Germany.
25.
Prouty
,
R.
,
1990
,
Helicopter Performance, Stability, and Control
,
2nd ed.
,
Krieger Publishing Company
,
Malabar, FL
.
26.
Freeman
,
C.
, and
Cumpsty
,
N. A.
,
1992
, “
Method for the Prediction of Supersonic Compressor Blade Performance
,”
J. Propul. Power
,
8
(
1
), pp.
199
208
.
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