Wind Tunnel Study of the Forces Due to Drafting in Dolphin Mother-Calf pairs

TL;DR

This study uses wind tunnel models to quantify the hydrodynamic drafting forces in dolphin mother-calf pairs, revealing configurations where forces are sufficient to assist calf movement.

Contribution

It provides the first quantitative measurements of drafting forces in dolphin pairs using wind tunnel experiments, advancing understanding of cetacean hydrodynamics.

Findings

Drafting forces can be large enough to support calf movement.

Certain configurations significantly enhance drafting efficiency.

Quantitative force data supports hydrodynamical explanations of calf-mother swimming behavior.

Abstract

Cetacean Calves keep up with their mothers while rapidly swimming, by a hydrodynamical effect called drafting. This has been observed in the wild and enclosed areas, and has been mathematically analyzed in the past, but no quantitative measures of the actual forces involved have been made. We built wind tunnel models of Mother-Calf pairs and present force measures for various geometries and relative placements.We show that under certain configurations, the drafting forces are large enough to carry the calf along effortlessly.