sport aviation of the future. possible concepts for future sport aircraft using different...
DESCRIPTION
Sport Aviation of the Future. Possible Concepts for Future Sport Aircraft Using Different Environmental Friendly Propulsion Concepts. Patrick Berry Fluid and Mechatronic Systems. Introduction. A new generation of sport aircraft will require radical changes to the propulsion system Why? - PowerPoint PPT PresentationTRANSCRIPT
Sport Aviation of the Future.Possible Concepts for Future Sport Aircraft Using
Different Environmental Friendly Propulsion Concepts
Patrick Berry
Fluid and Mechatronic Systems
Introduction
A new generation of sport aircraft will require radical changes to the propulsion system
Why? In the future fossile fuel will be scarce or at least limited and too
expensive Fossile fuel is bad for the environment and might also be
prohibited to use in the future because of its environmental impact
So what are the options?! 1) Use bio fuels 2) Go electric
ICAS 2010
Introduction
This study will focus on electric propulsion and what this means for the design and use of such aircraft
Different power sources like the sun, batteries and fuel cells will be covered
ICAS 2010
Solar powered aircraft
Sources of inspiration: Human powered aircraft
ICAS 2010
Gossamer Albatross
Daedalus (MIT)
Solar powered aircraft
Sources of inspiration: Solar powered aircraft
ICAS 2010
Powered configuration
Configured as a glider
Solair 2
Questions
Is it possible to design something like this which is commercially viable?
…. and to which category do we certify it? Is there a market? Will the market accept it?
ICAS 2010
Solar powered aircraft
The Sun peaks at 1000 W/m2 (in summertime, at noon on a clear day)
An average of 800 W/m2 can be expected (in southern Europe) This indicates flight times around 7 hrs on pure solar power But the aircraft won´t be able to take-off and climb on solar
power, so it needs to be a hybrid using batteries to assist Batteries are an additional dead weight which needs to be
minimised, so we are looking for a battery with high energy density (Wh/kg)
ICAS 2010
ICAS 2010
Battery trends in energy density
Quinetic Zephyr using Li-S (350 Wh/kg)Endurance: 2 weeks
ICAS 2010
Solar powered aircraft
Affordable solar cells are in the range of 15-20% in efficiency. We need to work with the most efficient ones in order to reduce size, weight and stay reasonable in cost
Essential to minimise losses in the overall power chain
ICAS 2010
Solar powered aircraft
How would you use such a plane? Due to its low power-to-weight ratio it´s more suitable as a
powered glider, i.e. a glider with self launch capability
ICAS 2010
Specification for a solar powered aircraft
Average solar radiation = 800 W/m2 Max. sink rate in glider configuration: less than 0.7 m/s Cruise speed in solar powered mode: 20% higher than stall
speed The aircraft shall be a hybrid, i.e. battery power for take-off and
climb, solar power for cruise Min. climb speed: 2m/s Single seater or two seater Pilot or passenger weight: 90 kg (+7 kg for parachute) Certification: CS 22, motorgliders
ICAS 2010
Typical sizing diagram for solar powered flight
ICAS 2010
Solar constraints
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 8000
Altitude (ft)
(W/S
)o (k
g/m
2)
Stall margin
Minimum sinkrate
Solar powered cruise
Initial cruise altitude
Design point solar powered a/c
Solar powered aircraft
Two configurations are presented:
1. Conventional layout
2. Canard configuration
ICAS 2010
ICAS 2010
ICAS 2010
23-04-22 Linköpings universitetSid 17
Conventional Single-seater Two seaterOverall length (m) 7.1 7.5
Span (m) 21.2 18.7 26.8 26.5A 23 23
S (m2) 19.6 15.3 31.2 30.4Empty weight (kg) 135 122 270 251Battery weight (kg) 36 (Li-ion) 25 (Li-S) 66 (Li-ion) 42 (Li-S)Pilot+parachute (kg) 90+7 194
MTOW (kg) 268 244 530 487Max shaft power (kW)(T-off, climb)
8 16
Solar shaft power (kW)(cruise)
2.2 2 4.1 4
Propeller dia. (m) 2 2
Cruise speed (km/h) 77 76 77(L/D)max 33 33
Endurance (h) 6.9 6.9
Climb rate (m/s) 1.8 2.1 1.7 1.9
ICAS 2010
ICAS 2010
ICAS 2010
Canard Single-seater Two seater
Overall length (m) 7.4 8
Span (m) 16.7 15.8 21.8 20.5A 18 18
S (m2) 15.4 13.9 26.5 23.4Empty weight (kg) 114 101 218 189
Battery weight (kg) 36 (Li-ion) 24 (Li-S) 66 (Li-ion) 39 (Li-S)
Pilot+parachute (kg) 90+7 194
MTOW (kg) 247 222 478 422Max shaft power (kW)(T-off, climb)
8 16
Solar shaft power (kW)(Cruise)
2.2 2 3.7 3.3
Propeller dia. (m) 2 2
Cruise speed (km/h) 80 76
(L/D)max 33 35
Endurance (h) 6.9 6.9
Climb rate (m/s) 2 2.2 1.8 2.1
ICAS 2010
Typical V-n diagram for a solar powered aircraft
ICAS 2010
Problem areas
Requires skilled pilot due to lack of excess power Solar cell integration on wing and stabilizer Solar cell integration requires stiff surfaces (brittle cells) Solar cells need to be embedded for low drag (without too
much energy losses) Aircraft limited in use as to where and when you can operate it Big question= Maintenance of solar cells!!
ICAS 2010
Problem areas
ICAS 2010
Battery powered aircraft
Source of inspiration:
PC Aero Electra OneICAS 2010
Battery powered aircraft
Battery powered aircraft are based on the sun powered configurations shown previously
Main difference: Wing loading can be increased since sun power is eliminated (saves weight)
Since battery weight will be even more dominant in this case, we need to decrease structure weight as much as possible (wing essentially)
No sun power means no need for non-tapered wings any more, i.e. weight potential
Aspect ratio can be reduced (weight saver), which means somewhat reduced soaring performance,
ICAS 2010
Specification for a battery powered aircraft
Maximize range/endurance Min. cruise speed : 20% higher than stall speed Min. climb speed: 2m/s Single seater or two seater Pilot or passenger weight: 90 kg (+7 kg for parachute) Certification: CS 22, motorgliders
23-04-22 Linköpings universitetSid 26 ICAS 2010
ICAS 2010
ICAS 2010
Conventional Single-seater Two seater
Overall length (m) 7.6 8
Span (m) 11.7 16.4
A 15 15
S (m2) 9.1 17.9
Empty weight (kg) 101 189
Battery weight (kg) 76 (Li-ion) 76 (Li-S) 155 (Li-ion) 155 (Li-S)
Pilot+parachute (kg) 90+7 194
MTOW (kg) 274 538
Max shaft power (kW) 12 25
Propeller dia. (m) 2 2
Min. cruise speed (km/h) 84 84
(L/D)max 26 27
Endurance (h) 2.7 4.5 2.7 4.4
Climb rate (m/s) 2 1.8
Max cruise speed (km/h) 160 160
23-04-22 Linköpings universitetSid 29 ICAS 2010
Canard Single-seater Two seater
Overall length (m) 7.6 8
Span (m) 10.8 15.2
A 13 13
S (m2) 9 17.7
Empty weight (kg) 97 183
Battery weight (kg) 76 (Li-ion) 76(Li-S) 155 (Li-ion) 155 (Li-S)
Pilot+parachute (kg) 90+7 194
MTOW (kg) 270 532
Max shaft power (kW) 12 25
Propeller dia. (m) 2 2
Min. cruise speed (km/h) 92 92
(L/D)max 28 30
Endurance (h) 2.9 4.5 2.9 4.4
Climb rate (m/s) 2.7 2.6
Max cruise speed (km/h) 160 160
23-04-22 Linköpings universitetSid 30 ICAS 2010
Pros and cons
Battery powered aircraft are probably the easiest way to replace current combustion engine types (except for bio fuels)
Battery powered aircraft have power to spare, thus easier to fly, require ”normal skilled pilots”
Might be more interesting for the market since range of speed is greater
Big pro = existing infrastructure! Limited use in terms of over the year useage Batteries don´t work that good in a cold environment
ICAS 2010
Fuel cell powered aircraft
Source of inspiration:
23-04-22 Linköpings universitetSid 32
DLR Antares
ICAS 2010
Fuel cell powered aircraft compared to battery powered
ICAS 2010
Fuel cell powered aircraft
The DLR Antares is a derivative of an existing aircraft. It carries two external wing pods. One is the hydrogen tank the other is the fuel cell
In a blank paper design you would probably try to integrate the tank and fuel cell more
One big problem is to house the large pressurised tank (45 MPa), needs to be placed close to the C of G
Suggestion: place it in the main spar!
ICAS 2010
Fuel cell powered aircraft
The fuel cell powered aircraft concepts are based on the battery powered concepts previously shown
Same specification Battery weight exchanged for fuel cell + tank weight Only differrence is in endurance
ICAS 2010
Conventional Single-seater Two seater
Overall length (m) 7.6 8
Span (m) 11.7 16.4
A 15 15
S (m2) 9.1 17.9
Empty weight (kg) 101 189
Battery weight (kg) 76 (Li-ion) (Fuel cell) 155 (Li-ion) (Fuel cell)
Pilot+parachute (kg) 90+7 194
MTOW (kg) 274 538
Max shaft power (kW) 12 25
Propeller dia. (m) 2 2
Min. cruise speed (km/h) 84 84
(L/D)max 26 27
Endurance (h) 2.7 3.5 2.7 3.2
Climb rate (m/s) 2 1.8
Max. cruise speed (km/h) 160 160
23-04-22 Linköpings universitetSid 36 ICAS 2010
Canard Single-seater Two seater
Overall length (m) 7.6 8
Span (m) 10.8 15.2
A 13 13
S (m2) 9 17.7
Empty weight (kg) 97 183
Battery weight (kg) 76 (Li-ion) (Fuel cell) 155 (Li-ion) (Fuel cell)
Pilot+parachute (kg) 90+7 194
MTOW (kg) 270 532
Max shaft power (kW) 12 25
Propeller dia. (m) 2 2
Min. cruise speed (km/h) 92 92
(L/D)max 28 30
Endurance (h) 2.9 3.5 2.9 3.2
Climb rate (m/s) 2.7 2.6
Max. cruise speed (km/h) 160 160
23-04-22 Linköpings universitetSid 37 ICAS 2010
Pros and cons
Technology seems promising Still in early development stage, not mature Lack of infrastructure!! Use is limited by the same reason as battery powered aircraft: Gas performance degrade with lower temperature
ICAS 2010
How we prepared the study
We used an in-house design program, which we rearranged The rearrangement included: Adding solar power model Adding electric motor model Adding battery model Adding fuel cell model Rearranged weight equations in weight module The electric motor model and weight equations were trimmed
against published Solair 2 data We benchmarked against existing aircraft in the category and
found good relevence
23-04-22 Linköpings universitetSid 39 ICAS 2010
Conclusions
This study has shown that it´s quite possible to design electric aircraft with different power sources, even using today´s technology
The ability to design light and with low drag is emphazised more than ever
”Green aircraft” won´t be any high speed machines Live ”green”= eat ”slow food” Fly ”green”= fly slowly Will the market accept slow flight? Personal view: the market might digest battery powered aircraft
in the very near future, but the other variants will probably have to wait for a while
ICAS 2010
Questions?
ICAS 2010