Concept and Applications:
A balloon-kite hybrid aerial platform which combines the properties and thus advantages of both a balloon and a kite is under development. A balloon is affixed with a kite at the bottom and this assembly is secured to the ground using a tether. To counter the phenomenon of lowering of height with increase in wind speed which is a major problem with tethered simple balloons and even aerodynamic balloons, better known as Aerostats, the kite part of the hybrid system, helps by providing a surface area so as to produce dynamic lift which goes on increasing with the increase in wind speed. This lift tries to push the system upwards thus, utilizing the wind to gain height instead of decreasing it. This is how the dynamic plus static lift and tether combination helps the hybrid system in maintaining the altitude of deployment. A twin barrel winch is used to secure the tether to the ground. This system on a whole (balloon+kite+tether), is lighter than air. A keel is attached perpendicular to the bottom surface of the kite. This keel aids in aligning the entire system in the wind direction.
The Balloon-Kite Hybrid System, on account of its dynamic lift, is a compact and relatively stable aerial platform which can find applications in the fields of agriculture, civilian surveillance, defense surveillance and weather analysis.
In agricultural applications, mounting visual and infrared cameras on this system, can help detect water stress on the crops at an early stage. Water stress is the deficiency of water in the crops either due to improper irrigation or over perspiration. This leads to subtle and gradual increase in crop temperature just like increase in temperature in us humans just before and during a disease. This technique makes the farmer aware of any impending crop health issues quite early and also assists in irrigation planning.
This system can also be used in cases of natural disasters to get an overview of the area under distress. Night lighting and Advertisement are also some of the domains where these systems can find applications in.
A small scale mock model of the system was made out of a gym ball and a specially designed and stitched kite to explore and understand various balloon- kite securing methods. An appropriate method was finalized to be adopted for the first 1:1 scale prototype, which was, as seen below, fabricated and tested for two weeks for leaks and trying out the feasibility of various balloon-kite attachment schemes. This prototype was designed to carry a payload of 3 kg. On account of few problems with the balloon kite attachment with this prototype a new and improved prototype is under development.
Design and Development: Chetan Dusane and Amit Wani
Guide: Prof. Debraj Chakraborty
Co.Guide: Prof. B.K. Chakravarthy, Prof. Rajkumar S. Pant
Supported by DIC