Ms. Kushwaha et P. Halevi, STOP BANDS FOR CUBIC ARRAYS OF SPHERICAL BALLOONS, The Journal of the Acoustical Society of America, 101(1), 1997, pp. 619-622
The acoustic band structures have been computed for cubic arrays of sp
herical hydrogen balloons in air. Stop bands are obtained for the face
-centered-cubic (fee) and body-centered-cubic (bcc) lattices, however,
there is no band gap for the simple cubic lattice. These gaps are lar
gest for a volume fraction of similar to 38% and, at low balloon press
ure (1.10 atm) and small latex wall thickness (10(-3) times the inner
radius), the corresponding gap/midgap ratios are about 0.2 for the fee
and 0.1 for the bcc structure. As the pressure or wall thickness incr
eases, the stop bands diminish and ultimately vanish. (C) 1997 Acousti
cal Society of America.