DEVELOPING AN UNDERSTANDING OF WASHING MACHINE DYNAMICS

This report summarises the findings of one of the problems presented at the 2006 MISG. The problem, presented by Fisher and Paykel, was to develop a better un-derstanding of the dynamics of modern washing machines that use ‘balance rings’. Balance rings are toroidal chambers that are partially filled with fluid. The wash-ing machine is a complicated system so several simplified systems were examined instead of attempting to model the complete system. These approaches included 1 experimental work using a washing machine with transparent balance rings and a strobe-light to observe the fluid-flow in the balance rings, 2 developing a 2D model of a balance ring and examining the system behaviour, 3 developing a simplified 3D model of a washing machine, without balance rings or an out-of-balance mass, and examining the system behaviour, 4 developing a simplified model to describe waves that might occur in the fluid within the balance rings. 1