Abstract.

This paper deals with the Lehmann rotation of banded cholesteric droplets subjected to a temperature gradient when they coexist with their own isotropic liquid. I show that their angular rotation velocity increases --in absolute value-- when they are subjected to an additional AC electric field in the conducting regime. This velocity increase is correlated with a prolate distortion of the droplets and the probable presence of electrohydrodynamical toroidal circulation flows inside and outside the droplets. I propose that the coupling between these flows and the director field is responsible for the increase of the angular velocity of the texture. The origin of these flows is discussed qualitatively in the framework of the leaky dielectric model by taking into account the generation of charges both in the bulk via a Carr-Helfrich mechanism (Tarasov, Krekhow and Kramer model) and at the surface of the droplet (Taylor-Melcher model).

Graphical abstract

中文翻译：

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振荡电场在胆甾型液滴的莱曼旋转中的作用。

摘要。

当带状胆甾型液滴与自身各向同性的液体共存时，本文研究了带状胆甾型液滴的Lehmann旋转。我显示出，当它们在导电状态下经受额外的交流电场时，它们的角旋转速度（绝对值）会增加。该速度的增加与液滴的明显变形以及液滴内部和外部可能存在的电动流体环形循环有关。我认为这些流与导向场之间的耦合是导致纹理角速度增加的原因。在渗漏电介质模型的框架内，通过考虑两个通道中的电荷的产生，定性地讨论了这些流的起源。 Carr-Helfrich机理（Tarasov，Krekhow和Kramer模型）和液滴表面（Taylor-Melcher模型）。

图形概要