密闭式电喷雾离子源中流场的分布特征

利用流体力学模拟软件Fluent构建了电喷雾离子源的二维模型，并基于所构建的模型探讨了离子源构型、辅助气引入方式、气体流速对源内流场分布的影响。结果表明，相比于其它两种结构，矩形结构的离子源能够提供较为稳定的流场。通入同轴辅助气和正交方向辅助气都能够起到聚集样品喷雾的效果，但作用效果却并不相同。提高同轴辅助气流速，能够增大喷口处混返区域，改变气流驻点位置。而增大正交方向辅助气流速，虽然同样能够提高源内各处气体流速，但并不会改变喷口处混返区域的大小。以Turbo V离子源为研究对象，考察了喷针位置、辅助气流速对溶液总离子流的影响，实验趋势与模拟结果基本吻合。

Numerical Simulation of Fluid Distribution in Closed Electrospray Ion Source

Two-dimensional axisymmetric simulations of electrospray ion source were built by Fluent software. The gas flow distribution was evaluated under comparable conditions, including configurations of ion source, ways to pump auxiliary gas and gas flow rates. The simulation results suggested that, rectangular ion source produced more stable flow distribution than other ion sources. Despite liquid flow was focused by both coaxial gas and orthogonal gas, the two pump ways had different effects on gas flow distribution. With the flow rate of coaxial gas increasing, backmixing region near the nozzle was enlarged and the stagnation point was changed, while the size of backmixing region was almost invariably with flow rate of orthogonal gas. The experimental validation was performed using Turbo V. The influences of spray needle position and gas flow rate on the detection of total ion current ( TIC) were investigated. The experimental results agreed well with numerical simulation results.