The onset of bioconvection in a suspension of negatively geotactic microorganisms with high-frequency vertical vibration

The effect of vertical vibration on the stability of a dilute suspension of negatively geotactic microorganisms in a fluid layer of finite depth is investigated. For the case of high-frequency vibration, solutions of governing equations are decomposed into two components: one which varies slowly with time and a second which varies rapidly with time. An averaging method is utilized to derive the equations describing the mean flow. Linear stability analysis is used to investigate stability of the obtained averaged equations. (c) 2005 Elsevier Ltd. All rights reserved.