engleski

Groundwater Flow Modeling in the Karst Aquifers: Coupling Laminar Matrix Flow and Turbulent Conduit Flow - Verification on Physical Model

Karst aquifers are characterized by the existence of the highly permeable conduit network embedded in less permeable rock matrix which makes them different from other aquifers. This duality in the permeability makes karst aquifers particular difficult to model. In this work we present novel numerical model for flow in karst aquifers. Slow laminar seepage flow in the karst matrix is described by equation for variably saturated porous medium flow. Flow in the conduits is usually turbulent and can be free surface or pressurized. Both flow conditions in the karst conduits are captured by 1D non-inertia wave equation. Iterative coupling of two flow domains is established through flux relation governed by pressure difference of two domains. Novel numerical approach based on Fup basis functions is used for spatial discretization of the governing equations. Due to similarity with the Isogeometric Analysis concept (IGA), we label it as Control Volume Isogeometric Analysis method (CV-IGA). Particular difficulty with complex 3D karst flow models lies in its verification due to lack of input data such as parameters of aquifer as well as position, shape and dimensions of conduit network. Therefore, this work shows possibility to verify karst flow models under the laboratory controlled conditions on the 3D physical model.

karst aquifers, control volume formulation, coupled 3D-1D numerical model, physical karst flow model

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