Perturbative analysis of the magnetic field effect on the stability of the shear flow of a nematic polymer

Abstract

The effect was investigated of an applied magnetic field on the stability of the shear flow of a nematic polymer liquid crystal of the tumbling type with respect to the formation of transient bands. For a given Ericksen number of the flow, the critical field that suppresses the thermally generated and shear amplified perturbations is calculated. The boundary in the control parameter space between the homogeneous and the band formation regime is calculated using a numerical simulation of the flow based on a time‐dependent perturbative analysis. It is also found that the critical wavevector of the bands increases with the field and decreases with the Ericksen number of the flow and with the shear strain when a magnetic field is applied.

Keywords:

• perturbative analysis
• magnetic field effect
• shear flow
• nematic polymer

Acknowledgements

This work was supported in part by the Fundação para a Ciência e a Tecnologia of Portugal under Research Contract POCI/CTM/61293/2004.