Building a `bladeless' fan from `spare parts'
by
Michael Page
Monash University

A well known British company released a `new' type of domestic fan onto the market late last year, with much `fanfare' and an apparently large marketing budget.

It is a novel design so, after a quick surf around their website, I began to think about the fluid mechanics behind the concept. They talk about `inducement' and `entrainment' of air into the flow and show some nice CFD simulations, but the theoretical basis seems to be quite simple and able to be explained using a several bits of simple theory that are usually left around in your average undergraduate fluid mechanics course. Some of the finer details can get a bit technical but they provide a nice opportunity to revise some of the advances in high-Reynolds-number flows over the last 50 years - so I will touch upon them briefly as well.

Date received: December 18, 2009