Whirling Tubes - Physics Demonstrations - Whirling Tubes | Physics Undergraduate Labs

Ensure a minimum 3-meter radius clear zone around the demonstrator during operation. The tube extends 1-1.5 meters and rotates rapidly, creating a strike hazard. Keep students, equipment, projectors, and other objects well outside the rotation path. Check overhead clearance for light fixtures and ceiling-mounted equipment.

Purpose

Demonstrates harmonics of an open pipe. Spinning a corrugated tube faster excites successively higher harmonics, producing discrete pitch jumps rather than a continuous glissando — a vivid illustration of standing wave modes in bounded systems.

Four corrugated plastic tubes with flared ends in orange, red-white striped, pink-green striped, and light blue, laid out on a gray surface

Figure 1: Whirling tubes of different lengths and colors. The corrugations create turbulent airflow when rotated, exciting standing wave resonances at harmonic frequencies determined by tube length.

Safety Warnings

Warning: Clearance Zone Required

Purpose