基于多单元均衡法的地下水流与水质联合数值研究

Combined numerical simulation of groundwater flow and quality based on multi-element balance

针对地下渗流与污染物迁移数值模拟中计算程序复杂、效率偏低等不足,开展了地下水流与水质联合数值研究。首先基于多单元均衡法,建立了渗流与污染物迁移的联合模型,采用Matlab语言编制了联合程序,使之能够求解单一地下水渗流、初始流场稳定的地下水污染和初始流场不稳定的地下水污染等多种情况。然后计算了一维对流弥散问题,并与多种计算方法进行对比分析。最后对某地地下水污染物的扩散分布进行了模拟。结果表明:通过控制自定义特征数,实现了对不同水文地质特征问题的求解;采用上游加权法解决大Peclet数污染物迁移问题时,并无明显数值弥散现象,又能抑制数值解的振动;本程序具有较高的计算效率,并能够显著提高后处理的可视化程度。

Aimed at the shortcomings of complexity and low efficiency of calculation program in numerical simulation of groundwater flow and contaminant transport, the paper studied a combined numerical simulation of groundwater flow and quality. Based on MEB, it firstly built a coupled model of groundwater flow and contaminant transport and programmed a coupled program by using Matlab so as to solve single flow, contaminant transport with steady flow and contaminant transport with unsteady flow. Then it studied one dimensional solute transport by using the program and compared the method with other ones. Finally, the paper simulated the diffusion distribution of groundwater pollutant in a certain place. Results show that by controlling the custom feature numbers, the paper solved the problem of different hydro - geological characteristics; when using upstream weighted method to resolve the problem of big Peeler number pollution dispersion, there no obvious numerical dispersion phenomenon and. the method can solve the vibration of numerical solutions;the program has higher computing efficiency and can significantly improve the visibil- ity of postproeessing.