Charge transport measurement during turbulent electroconvection

We report measurements of the energy dissipation during electroconvection of a nematic liquid crystal in the fully turbulent regime. The energy dissipation is quantified by measuring the electric current at constant potential difference. In certain cases, we observe the surprising result that the dimensionless energy dissipation ceases to increase with increasing potential difference. In some circumstances, a power-law scaling relationship between the dimensionless excess energy dissipation and the reduced voltage is observed, but the exponent in this relationship varies dramatically with both the time scale of the driving electric field and the separation between the electrodes.