WASHINGTON - In a new research, scientists have determined that some dolphins’ fins generate lift in the same way as delta wing aircraft.
The research was conducted by Laurens Howle and Paul Weber from Duke University, who teamed up with Mark Murray from the United States Naval Academy and Frank Fish from West Chester University, to find out more about the hydrodynamics of whale and dolphin flippers.
Using Computer tomography scanning of the fins of seven different species ranging from the slow swimming Amazon River dolphin and pygmy sperm whale to the super-fast striped dolphin, the team made scaled models of the flippers of each species.
Then, they measured the lift and drag experienced by the flipper at inclinations ranging from -45degrees to +45degrees in a flow tunnel running at a speed that would have been the equivalent of 2m/s for the full scale fin.
Comparing the lift and drag coefficients that the team calculated for each flipper at different inclination angles, they found that the flippers behave like modern engineered aerofoils.
Defining the flippers’ shapes as triangular, swept pointed or swept rounded, the team used computer simulations of the fluid flows around the flippers and found that sweptback flippers generate lift like modern delta wing aircraft.
Calculating the flippers’ efficiencies, the team found that the bottle nose dolphin’s triangular flippers are the most efficient while the harbour porpoise and Atlantic white-sided dolphin’s fins were the least efficient.
Howle and his colleagues will try to find out more about the link between the flippers’ performances and the environment that whales and dolphins negotiate on a daily basis. (ANI)