Related Experiment Video
Updated: Jan 30, 2026

Laboratory Scale Slow Cook-Off Testing of Rocket Propellants: The Combustion Rate Analysis of a Slowly Heated Propellant CRASH-P Test
Published on: February 6, 2021
Bifurcation in the angular velocity of a circular disk propelled by symmetrically distributed camphor pills
Yuki Koyano1, Hiroyuki Kitahata1, Marian Gryciuk2
1Department of Physics, Chiba University, Chiba 263-8522, Japan.
Abstract:
We studied rotation of a disk propelled by a number of camphor pills symmetrically distributed at its edge. The disk was put on a water surface so that it could rotate around a vertical axis located at the disk center. In such a system, the driving torque originates from surface tension difference resulting from inhomogeneous surface concentration of camphor molecules released from the pills. Here, we investigated the dependence of the stationary angular velocity on the disk radius and on the number of pills. The work extends our previous study on a linear rotor propelled by two camphor pills [Y. Koyano et al., Phys. Rev. E 96, 012609 (2017)]. It was observed that the angular velocity dropped to zero after a critical number of pills was exceeded. Such behavior was confirmed by a numerical model of time evolution of the rotor. The model predicts that, for a fixed friction coefficient, the speed of pills can be accurately represented by a function of the linear number density of pills. We also present bifurcation analysis of the conditions at which the transition between a standing and a rotating disk appears.
Related Concept Videos
Angular Velocity and Displacement
Angular Velocity and Acceleration
Circular Orbits and Critical Velocity for Satellites
Nicolaus Copernicus (1473-1543) first suggested that the Earth and all other planets orbit the Sun in...
Symmetric Member in Bending
Deformations in a Symmetric Member in Bending
When the member is segmented into tiny cubic elements, it is observed that the primary stress...
Faraday Disk Dynamo

