Research On Hydrogeological Parameter Inversion Method Based On Fluid-solid Coupling

Various hydrogeological parameters in the aquifer are widely used in the numerical simulation of groundwater,pollutant migration,dynamic monitoring,environmental evolution,water resources evaluation and other research.The solution of hydrogeological parameters has generally tended to be intelligent,and various improved optimization algorithms have also been widely used,which makes the calculation of hydrogeological parameters at the two-dimensional level reach a highly intelligent level.Although the two-dimensional aquifer model can quickly solve hydrogeological parameters,it cannot accurately describe the structural characteristics of aquifers,resulting in poor solution accuracy.Therefore,the focus and difficulty of the current hydrogeological parameter calculation is to establish a three-dimensional aquifer model that can accurately describe the complex rather than idealized real aquifer conditions,and find the corresponding solution method.In this thesis,the research methods of inversion theory analysis and numerical simulation are combined.In the aquifer with certain geological structure characteristics,the fluid-solid coupling method is used to invert two kinds of hydrogeological parameters.The research shows that the inversion method based on fluid-solid coupling can better solve the multi-solution problem of inversion,and finally obtain more accurate and higher resolution hydrogeological parameter inversion results.Specific research work and results are as follows :(1)Considering the interaction between fluid and solid structure in the process of water flow in porous media aquifer,the fluid-solid coupling control equation is deduced according to the groundwater flow control equation and solid mechanics equation.Based on the spatial distribution information of aquifer,the fluid-solid coupling aquifer model is established by using COMSOL numerical simulation software.(2)Taking the three-dimensional phreatic aquifer Newman model as an example,the intelligent optimization wiring method for the standard curve as the curve family is studied.The standard curve is divided into group A curve and group B curve according to the concave and concave.The group A curve or group B curve is first matched to obtain the β value of the target optimal curve,and then the other group of curves is matched with the curve with the same β value.In order to shorten the time of drawing the standard curve family,the numerical solution of the standard curve of the Newman well function is obtained by using the complex Simpson formula.(3)The co-simulation platform of COMSOL and MATLAB is constructed.Firstly,the three-dimensional fluid-solid coupling aquifer model is constructed based on COMSOL,then the model is imported into MATLAB to realize the three-dimensional intelligent optimization algorithm of aquifer parameters.Based on this platform,SAPSO algorithm,Rand WPSO algorithm,Simu PSO algorithm and BOBYQA algorithm are solved.The results show that the accuracy,stability and convergence of Simu PSO algorithm and SAPSO algorithm based on MATLAB are better than BOBYQA algorithm.