Modelling of a horizontal-axis domestic washing machine

This pap er examines the design of the horizontal-axis washing machine by means of parametric modelling and the description of the motion of articles, e.g. clothes, in it during the washing process. A series of dimensionless factors is determined that characterise the horizontal-axis washing machine. These parameters can be interlaced and correlated to machine performance, including soil-removal efficiency and effectiveness. In this way, it is possible to optimise the machine configuration, such as the drum diameter, angular speed, depth, etc. The motion of the wash load is also modelled by means of an imaginary fabric plug and by dividing the rotation of the wash load into three distinct steps. The resulting cycle provides a means of calculating the theoretical fabric-plug pressure drop, which is known to drive local hydrodynamic conditions, including fluid flow. Two methods of determining the fabric-plug impact velocity are also proposed, including one based on the 'added-mass' concept. The question of machine comparison and scalability is tackled by means of geometric, dynamic, and kinematic similarity.