Indian Institute of Technology Kanpur
Abstract :
We are interested in a certain class of bifacial Indian drums,
such as dholak, pakhawaj, and mrdangam, which consist of
composite circular membranes stretched over an enclosed air
cavity on both sides of an axisymmetric wooden shell. There
is a large variety of such drums in Indian music which differ
from each other in shapes and sizes of the shell and in the
nature of the composite membranes. These drums produce
sounds which have a definite pitch and hence can be
qualified as musical in nature. Whereas, the effect of the
composite nature of the membrane is well studied in the
context of the monofacial Indian drum tabla, the acoustical
implications of the coupling between two composite
membranes (of different material and geometric properties)
through an air cavity remains unexplored. The purpose of
this work is to study this acoustical problem using a finite
element method based numerical methodology. The aim is to
solve the coupled structural acoustic boundary-value-problem
for the enclosed air pressure and the membrane vibration. In
our detailed investigation, we will study the effect of cavity
size and shape, as well as the properties of the composite
membranes, on the acoustics of the bifacial drums.