Kites and maritime applications
Kite basics
Airborne Wind Energy
Other applications
Robokite example
Kite basics
Forces on a kite
- Aerodynamic forces
- Tether forces
- Weight
L'aile d'eau, p54
Flight window
Lift to drag ratio
L/D = Lift/Drag = Vx/Vz
Vmax = L/D * Vwind
Text
For a falling glider:
For a kite:
Vmax kite
Vwind
Wind profile
u = u_r\bigg(\frac{z}{z_r} \bigg)^\alpha
u_z = \frac{u_*}{\kappa} \left[\ln \left(\frac{z-d}{z_0} \right) \right]
Airborne Wind Energy
Marine propulsion
Power production
1890
1980
"Crosswind kite power", Loyd
KiteGen foundation
2007
Makani power foundation
2006
Skysails foundation
2001
Transatlantic with 320m2 automated
2008
P = {2 \over 27} \rho_a A C_L({C_L \over C_D})^2 V^3
1990
Dyneema commercialization
2006
DJI foundation
2010
ARDrone
2009
Ardupilot/3DR robotics
UHMPE fibers
- Commonly named Dyneema (1990)
- 15g per m, per ton
- 2.4GPa
Electronics/Flight controllers
- Small and cheap components due to consumer electronics
- IMU "10dof" from around 15€
- Open hardware development (Arduino(2005)/APM)
Ship propulsion
Sailboat vs kiteboat
- Rigid mast
- Heeling moment
- Ballast keel or costly multihull
http://project.kiteboat.com
- No (or small) mast
- No (or small) heeling moment
- Potentially no hull!
http://project.kiteboat.com
From small to big
- Kitesurf
- Kiteboat
- Kitefoiler
- Fishing boat
- Cargo
- Container ship?
Flying wind turbines
- Cart on a rail
- Yoyo
- Turbine
- And much more...
Get rid of mast (50% of cost)!
Lighter or heavier than air?
Flygen or Groundgen?
High tech or low tech?
Onshore or Offshore?
Other applications
- Added visibility for rescue
- Increased range for sensors
