Figure 3.
Schematic of two tubes separated by a distance x. The sound field included within the cone having height x, vertex angle θ, and base 4πa2 is supposed to couple with the opposite tube.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.