A one-dimensional model for ion transport in a flame with two absorbing surfaces
A one-dimensional model for ion transport in a flame with two absorbing surfaces
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DOI：
10.1080/13647830.2020.1826581
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发表时间：
2020-09
影响因子：
1.3
通讯作者：
Christopher R. Martin;A. Untaroiu;Kemu Xu
中科院分区：
文献类型：
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作者：
Christopher R. Martin;A. Untaroiu;Kemu Xu
本文提出了使用一维离子传输模型的火焰电流-电压特性的数值和渐近解析解，其边界条件包括对鞘层形成的详细处理。给出了具有均匀速度、电迁移率和扩散率的一维流场中的自由电子、水合氢离子和电势的无维守恒方程，但考虑了非平衡电子温度。在这项研究中，改变了离子形成区域的大小和位置以及电雷诺数，并研究了它们的影响。该模型预测了域两端带电鞘层的形成，这导致了实验中可靠观察到的饱和事件。模型中可以出现新的饱和状态，但实验中没有出现该饱和状态被认为会对实验中吸收表面附近的传输产生影响。例如，电流-电压特性收敛到实验中观察到的形状和大小的雷诺数意味着鞘层在实际流动的低速区域形成，从而降低了表观雷诺数。
This paper presents numerical and asymptotic analytical solutions for the current–voltage characteristic of a flame using a one-dimensional ion transport model with boundary conditions that include detailed treatment of sheath formation. Non-dimensional conservation equations are presented for the free electron, the hydronium ion, and the electrical potential in a one-dimensional flow field with uniform velocity, electrical mobility, and diffusivity, but allowances are made for non-equilibrium electron temperature. In this study, the size and location of the ion formation region and the electric Reynolds numbers are changed, and their impacts are studied. The model predicts the formation of charged sheaths at both ends of the domain, which are responsible for saturation events that are reliably observed in experiments. A new saturation regime can be made to appear in the model, but its absence from the experiment is argued to have implications on transport near absorbing surfaces in the experiment. For example, the Reynolds numbers at which the current–voltage characteristic converges to the shape and magnitude observed in the experiment implies that the sheaths form in the low-velocity region in the real flow that reduces the apparent Reynolds number.