Li Gaojin, Archer Lynden A, Koch Donald L
Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, USA.
Phys Rev Lett. 2019 Mar 29;122(12):124501. doi: 10.1103/PhysRevLett.122.124501.
Direct numerical simulations of a liquid electrolyte with polymer additives demonstrate that viscoelasticity promotes an earlier transition from steady to unsteady electroconvective flow. Viscoelasticity also decreases the overlimiting current resulting from convection by up to 40%. Both of these effects would reduce the time-averaged spatial variability of ion flux suggesting that polymeric fluids may inhibit dendrite growth. Polymer relaxation near a surface destabilizes the flow structures and decreases the time duration of high current fluxes. This mechanism of polymer-induced flux reduction is general to wall bounded flows with transfer of mass, heat or momentum.
对含有聚合物添加剂的液体电解质进行的直接数值模拟表明，粘弹性促进了从稳定到非稳定电对流的更早转变。粘弹性还使由对流产生的过极限电流降低了40%。这两种效应都会降低离子通量的时间平均空间变异性，表明聚合物流体可能抑制枝晶生长。表面附近的聚合物松弛会使流动结构失稳，并缩短高电流通量的持续时间。聚合物引起通量降低的这种机制对于有质量、热量或动量传递的壁面边界流动是普遍适用的。
