Abstract:
It is known that suspensions of swimming microorganisms are susceptible to an instability that arises from the hydrodynamic stresses the microorganisms exert upon their fluid medium. These stresses are sometimes referred to as bacterial stresses. In this paper we examine the case where the nature of the swimming motion is such that these bacterial stresses are relatively weak and show that the form of the instability can be influenced by irrotational components of the flow fields generated by the swimmers.
