利用强迫流示踪反演地下岩溶的空间维度

Estimation of the spatial dimension of underground karst cave basing on forced flow tracer experiment method

利用Fluent有限差分数值模拟软件,模拟饱水空间强迫流示踪中搅拌桨转速对示踪曲线的影响。试验结果表明:封闭岩溶洞穴流场中投源点处示踪剂浓度历时曲线转折点的出现时间随水动力条件的提升而提前,在一维岩溶洞穴中,与转折点对应的示踪剂浓度随水动力条件的提升而降低,二、三维岩溶洞穴中则会出现转折点对应的示踪剂浓度随水动力条件的提升而升高;在二、三维岩溶洞穴中,当水动力强度较小时,示踪剂运移的速率与水动力条件关系不大,且随其提升而稳定提升,当水动力强度较大时,示踪剂运移的速率则随水动力条件的提升呈非线性提升。故通过对强迫流示踪曲线形状的分析可以推断出地下岩溶洞穴的大致空间维度。

This paper discuss the numerical simulation of impeller rotational speed＇s impact to force flow trace experiment. Final tracer concentration duration curves indicate that the in the flow field of karst caves,the time inflection points appear on tracer concentration duration curve are brought forward as the hydrodynamic condition is promoted,and in 1D karst caves,tracer concentrate correspond to inflection points reduce along with the ascension of the hydrodynamic condition,in 2,3D karst caves,it may rise the phenomenon that tracer concentrate correspond to inflection points rise along with the ascension of the hydrodynamic. In 2,3D karst carves,when hydrodynamic intensity is small,the tracer＇s migration has little to do with the hydrodynamic conditions and increase steadily as the hydrodynamic conditions promote,when hydrodynamic intensity is large,tracer migration rate rise in nonlinear as the hydrodynamic conditions promote. Therefore,through the analysis of the force flow tracer curve＇s shape can roughly deduce the underground karst cave＇s spatial dimension.