Hornbostel - Sachs
Stopped side-blown flutes without fingerholes
The air itself is the vibrator in the primary sense. The standing waves are significantly confined within the instrument itself. The player blows against the sharp rim of a hole in the side of a tube. The distal end of the tube has a fixed stopper. The instrument has no fingerholes. Apparently non-existent.
Stopped side-blown flutes without fingerholes, with fixed stopped lower end