Dynamic properties in beam formation of the Indo-Pacific humpback dolphin

¹ Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, College of Ocean and Earth Sciences, Xiamen University - Xiamen 361005, Fujian, China
² Biology Department, Woods Hole Oceanographic Institution - Woods Hole, MA 02543, USA
³ Department of Mechanical Engineering, Massachusetts Institute of Technology - Cambridge, 02139 MA, USA
⁴ Third Institute of Oceanography, State Oceanic Administration - Xiamen 361005, Fujian, China

^(a) yuzhang@xmu.edu.cn

Received: 30 August 2018
Accepted: 18 December 2018

Abstract

In this letter, a numerical head model is inspired from an Indo-Pacific humpback dolphin to investigate its acoustic field and beam patterns. The numerical solutions show a dynamic property of the beam patterns. The beam has a minimum width outside but close to the head. Then it widens before reaching a stable state in far distances. Sound pressure along the axis is the highest around the sound source. Afterwards, it decreases rapidly and fluctuates, reaching a local maximum before sounds spread into water, where the axial pressure amplitude decreases with the increase of distance.