Airships at IIT Bombay
During 2003 – 2006, I worked with the Lighter-Than-Air lab, at the Aerospace department of IIT Bombay, primarily during my summer vacations. I was offered this opportunity as a result of the work I completed for a KVPY scholarship in the first year of engineering (Freshman year). Some details of the KVPY project here.
For two summers (internships) and for my final year undergraduate project, I worked with Prof Pant, who is spearheading the effort in India to develop airship technology from the grassroots level.
A brief summary of the work, chronologically:
Summer internships (2004, 2005):
- Designed and fabricated unique 2 m PTFE hull for an indoor airship. The hull shape was a lenticular airship, which is an axisymmetric shape (like a UFO). This shape was selected to allow a centrally placed thrust vectoring system, and enable zero-radius turns in tight indoor spots.
- I worked on parametric modeling of the hull, lift calculations to determine payload capacity (and give my two team mates their design margins for the thrust vectoring mechanism, and the wireless electronics).
- I learnt Fluent™ and Gambit, and performed preliminary drag analysis on 2-D axisymmetric FE models
- As a team, we researched and characterized materials available in the Indian market, performed 3D to 2D petal decomposition, and fabricated and tested the airship using Helium.
- Developed operating protocols for unpacking, inflation, flight and storage of RC airships
This work was selected for the 2nd place – National Level Design competition, National Institute of Technology, India. A poster paper on ‘Design, fabrication and testing of a Remotely Controlled Airship with Thrust Vectoring’ ranked 2nd at International seminar, Aeronautical Society of India
.Final year undergraduate project (2006):
This project took the work done in summer internships to the next level. The aim was to find and test some alternative materials in the Indian market, and fabricate a 3m airship with a conventional shape that Prof Pant can use to spread airship knowledge and awareness around the country.Some of the work done:
- Material search in markets in Mumbai & Pune. Identified alternate PTFE materials and a proprietary ‘Metallised Polyester’ (with a surface density of 57 gsm) capable of holding in Helium as well as Hydrogen.
- Determination of material properties using ASTM D882 test method
- Development of codes to analyze different hull shapes (from standard shapes like the GNV Rao shape, to non standard shapes) to determine competing functions of lift, envelope weight, available payload and drag.
- Gondola design for reconfigurable payloads (for wireless cameras etc); thrust vectoring mechanisms using servo motors, neodynamic motors and 4 channel wireless transmitter-receivers.
- Prototype model development to understand effects of temperature, sealing time, pressure on resulting welds. Design of end-shapes to ensure leak-free joints.