Exploration of the Potential of Civil Unmanned Aerial Vehicles

121 Pages·2015·4.11 MB·English

Exploration of the Potential of Civil Unmanned Aerial

Vehicles Powered by Micro Gas Turbine Propulsion

System

Master Thesis

S.M.L. Beuselinck

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Exploration of the Potential of Civil
Unmanned Aerial Vehicles Powered by
Micro Gas Turbine Propulsion System
Master Thesis

By
S.M.L. BEUSELINCK

In partial fulfilment of the requirements for the degree of

Master of Science
in Aerospace Engineering

at the Faculty of Aerospace Engineering,
of the Delft University of Technology,

Kluyverweg 1
2629HS Delft
The Netherlands

Supervisors: Prof. dr. ir. P. Colonna
Dr. ir. M. Voskuijl
Ir. W.P.J. Visser

This thesis is confidential and cannot be made public until May 13, 2015.
An electronic version of this thesis is available at http://repository.tudelft.nl/.
Thesis Registration Number: 029#15#MT#FPP

DELFT UNIVERSITY OF TECHNOLOGY
DEPARTMENT OF
FLIGHT PERFORMANCE AND PROPULSION
The undersigned hereby certify that they have read and recommend to the Faculty of Aerospace Engineering
of the Delft University of Technology for acceptance a Master thesis entitled “Exploration of the Potential
of Civil Unmanned Aerial vehicles Powered by Micro Gas Turbine Propulsion System” by S.L.M.
Beuselinck in partial fulfilment of the requirements for the degree of Master of Science in Aerospace
Engineering.

Date: May 13, 2015

Head of department:
Prof. dr. ir. P. Colonna

Supervisor:
Dr. ir. M. Voskuijl

Supervisor:
Ir. W.P.J. Visser

Reader:
Dr. R. Pecnik

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Executive Summary

Civil Unmanned Aerial Vehicles (UAVs) are outnumbered compared to the military equivalents. They could
however be of great value to various organizations, companies and the general public. They currently seem
to be on the verge of a breakthrough. An interesting technology that could help increase the flight
performance of civil UAVs is the micro gas turbine technology. This is a promising propulsion system that is
being developed at the moment. It could become a solid competitor for other propulsion systems used to
power UAVs due to the higher power-to-weight ratio, lower complexity, higher energy density potential
and power density advantage. This could fuel the continuous expansion of civil UAVs even more. The
objective of this Master thesis is to investigate the difference in flight performance between a UAV
powered by a reciprocating engine and a micro gas turbine; to explore the potential of a UAV powered by
a micro gas turbine based propulsion system.
The exploration study first identifies the most promising application. Followed by nominating an existing
UAV design as a baseline, based on the closest requirement match with the selected application. The
Harfang EADS, powered by a Rotax 914 turbocharged reciprocating engine, acts as the baseline UAV. The
flight performance of this UAV is determined by a software package in which point performance is
integrated to obtain path performance of a typical mission profile. The aerodynamic model of the baseline
UAV is determined using a combination of a vortex lattice method and the thin plate approximation.
Weight estimation relationships are used to determine the components weight and the center of gravity
location. Fuel flow and thrust data of the reciprocating engine are derived from the operating manual of
the Rotax 914 engine, while thrust management tables from another Master thesis are used to model
different micro gas turbine sizes (86, 70 and 60 kW), each having a number of technology levels. The
influence of some of the assumed parameters is investigated by a sensitivity analysis. Minor modifications
to the UAV dimensions resulted in a none notable effect on the mission performance of the baseline UAV.
Increasing the critical Reynolds number on the other hand had a significant effect on the drag coefficient,
while the influence of the Oswald factor on the drag coefficient gradually increased as function of the angle
of attack. Changes to the drag coefficient and user-specified propeller propulsion efficiency of the baseline
UAV both had limited effect on the mission performance. Modifications to the specific fuel consumption of
the reciprocating engine resulted in a more pronounced effect.
The research indicates an increase in mission endurance of 4% for the 60 kW micro gas turbine with the
highest technology level compared to the reciprocating engine using the same UAV platform. A take-off
weight reduction of 18% can be obtained if the UAV platform is optimized for this micro gas turbine by a
redesign process; modifying the wing, fuselage and empennage design. The fuel weight is reduced by
12.5% compared to the reciprocating engine as a result of the increased mission endurance and redesign
process. The micro gas turbine can therefore perform the same mission as the reciprocating engine with
less fuel. This Master thesis therefore concluded that there is a performance gain possible if a reciprocating
engine is replaced by a micro gas turbine. This performance gain could also be transformed into a fuel
weight reduction, proving the potential of civil UAVs powered by a micro gas turbine based propulsion
system.

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Acknowledgements
I would like to express my gratitude towards my supervisors Mark Voskuijl, Wilfried Visser and
Piero Colonna for their guidance, advice and contributions towards this Master thesis. I would also
like to thank Rene Pecnik for being part of the examination committee, taking the time to asses my
thesis work.
Thanks to Anna Marcellan with whom I worked with during this Master thesis. It was a very
pleasant experience to exchange knowledge with her and discuss both work-related and off-topic
subjects.
I am grateful for all the friends I made at the faculty of Aerospace Engineering. I would not have
made it this far without you. Finally, many thanks go to my parents and family for always
supporting my efforts and believing in me.
Sander Beuselinck
Delft, May 2015

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