The longest known insect migration: Fusing Biology with Aerospace Engineering for innovative solutions
March 17 @ 11:00 AM - 1:00 PM
The intriguing annual migration of the dragonfly species, Pantala flavescens, was reported a century ago.
The multi-generational, transoceanic migration circuit spanning 14000-18000 kms, from India to Africa is an
astonishing feat for an insect few cms in size. Wind, precipitation, fuel, breeding, and the life cycle affect
the migration, yet understanding of their collective role in the migration remains elusive. We identify the
transoceanic migration route by imposing a time constraint emerging from energetics on Dijkstra’s
path-planning algorithm. Energetics calculations reveal Pantala flavescens can endure 90 hours of steady
flight at 4.5m/s. We incorporate active wind compensation in Dijkstra’s algorithm to compute the migration
route from years 2002 to 2007. The prevailing winds play a pivotal role; a direct crossing of the Indian Ocean
from Africa to India is feasible with the Somali Jet, whereas the return requires stopovers in Maldives and Seychelles.
The migration timing, identified using monthly-successful trajectories, life cycle, and precipitation data,
corroborates reported observations. While working on this problem my mind ventured into many different
applications of engineering, which are all connected to the transoceanic migration of dragonflies.
The applications range from designing airfoils/wings, sports aerodynamics and wind turbines to developing
novel spectral accuracy algorithms for numerical simulations. Hence the ideas vary from simple mimicking
of dragonflies to more complex abstractions arising from the need to understand their flying behaviour.
Speaker: Dr Sandeep Saha
Biography :
Dr Sandeep Saha is an Associate Professor in the Department of Aerospace Engineering, IIT Kharagpur.
He obtained his bachelors and masters degrees in Mechanical Engineering from IIT Kharagpur.
He completed his PhD in Mechanical Engineering from Imperial College London. He thereafter worked as a
Marie-Curie Experienced Researcher, CNRS (Laboratoire FAST), Orsay, France. Thereafter he worked as
an Aerodynamics Engineer, ALSTOM Power (now GE), Rugby, UK; then as Research Scientist (Fluids),
Schlumberger Gould Research, Cambridge, UK; and then as Academic Staff member, Mechanical Engineering,
University of Duisburg-Essen, Germany (in collaboration with SIEMENS AG). He has worked on a range of
problems in fluid mechanics and in recent years has focused on Low Reynolds number Aerodynamics
ranging a broad spectrum of problems like insect flight, extraterrestrial flight, respiratory flows and
waste heat recovery and sports aerodynamics.