In this study, the electrokinetic energy conversion efficiency is investigated theoretically in high pressure-driven flow with the pressure-viscosity effect. Calculations of the electrokinetic flow in a straight nanochannel are based on the Poisson-Boltzmann equation and modified fluid momentum equation. Once the viscosity of fluid is dependent on the pressure, the strongly non-linear governing equation should be solved simultaneously due to the unknown fluid viscosity. Thus, the domain perturbation method is used to solve the distributions of flow velocity and pressure. Based on obtained velocity and pressure, the maximum conversion efficiency is calculated by thermodynamic analysis. Results show the maximum efficiency increases with the decrease of salt concentration and the peak efficiency can be obtained at sufficiently low salt concentration. For a given salt concentration, the maximum efficiency decreases monotonously with the increase of pressure-viscosity coefficient. Besides, the maximum energy conversion efficiency of ignoring the pressure-viscosity effect is larger than that of considering the pressure-viscosity effect.

在这项研究中，在具有压力 - 粘度效应的高压驱动流中，电动能量转换效率在理论上进行了研究。直纳米通道中电动流动的计算基于泊松-玻尔兹曼方程和修正的流体动量方程。一旦流体的粘度取决于压力，由于未知的流体粘度，强非线性控制方程应同时求解。因此，域摄动法用于求解流速和压力的分布。基于获得的速度和压力，通过热力学分析计算最大转换效率。结果表明，最大效率随着盐浓度的降低而增加，并且在足够低的盐浓度下可以获得峰值效率。对于给定的盐浓度，最大效率随着压力-粘度系数的增加而单调下降。此外，忽略压力-粘度效应的最大能量转换效率大于考虑压力-粘度效应的最大能量转换效率。