Related Experiment Video
Updated: Jun 21, 2026
08:01
The Diffusion of Passive Tracers in Laminar Shear Flow
Published on: May 1, 2018
Variable-density flow in heterogeneous porous media--laboratory experiments and numerical simulations
1Department of Environmental Sciences, University of Basel, Institute of Geology, Applied and Environmental Geology, Switzerland. markus.konz@ifu.baug.ethz.ch
Journal of Contaminant Hydrology
|August 14, 2009
Summary
This study tested density-driven flow in heterogeneous porous media using lab experiments and numerical simulations. Results show dispersion depends on density, requiring reduced dispersivity for accurate modeling.
Area of Science:
- Environmental Science
- Geosciences
- Hydrology
Background:
- Previous work focused on density-driven flow in homogeneous porous media.
- Extending studies to heterogeneous media is crucial for realistic environmental modeling.
Purpose of the Study:
- To conduct and simulate laboratory experiments for density-driven flow in heterogeneous porous media.
- To validate numerical models under complex subsurface conditions.
Main Methods:
- Constructed a 2D heterogeneous porous medium tank with a central low-permeability zone.
- Employed high-resolution photometric and image analysis for concentration measurement.
- Utilized the Method of Lines (MOL) for advanced spatial and temporal discretization in numerical simulations.
Main Results:
- Density-dependent dispersion was observed in all simulated flow scenarios.
- Reduced dispersivity values were necessary to match experimental data accurately.
- High-quality experimental data provided reliable benchmark tests for variable-density flow codes.
Conclusions:
- The study successfully extended density-driven flow research to heterogeneous porous media.
- The findings highlight the importance of accounting for density effects on dispersion in complex environments.
- The validated numerical model and experimental data serve as valuable benchmarks for future research.
Related Concept Videos
01:17Steady, Laminar Flow Between Parallel Plates
Understanding steady, laminar flow between parallel plates is essential for analyzing and designing flow in narrow rectangular channels, commonly found in various water conveyance and drainage systems. The Navier-Stokes equations govern fluid motion and are generally challenging to solve due to their nonlinearity. However, simplifications are possible in certain cases, like the steady laminar flow between parallel plates. For this scenario, we assume steady, incompressible, laminar flow.
01:23Steady, Laminar Flow in Circular Tubes
Hagen-Poiseuille flow describes a viscous fluid's steady, incompressible flow through a cylindrical tube with a constant radius R. This flow profile is often applied to understand fluid transport in narrow channels, such as capillaries. It serves as a foundational example of laminar flow. In this model, cylindrical coordinates (r,θ,z) are used to describe the radial (r), angular (θ), and axial (z) dimensions within the tube. For Hagen-Poiseuille flow, the velocity profile is purely axial,...
01:27Uniform Depth Channel Flow
Uniform depth channel flow keeps fluid depth consistent along channels such as irrigation canals. In natural channels, such as rivers, approximate uniform flow is often assumed. This condition occurs when the channel’s bottom slope matches the energy slope, balancing potential energy lost from gravity with head loss due to shear stress. This balance prevents depth changes along the channel length, resulting in a steady, uniform flow.Uniform flow in open channels with a constant cross-section...
01:30Typical Model Studies
Fluid mechanics model studies often utilize scaled-down systems to predict fluid behavior in full-scale environments, such as river flows, dam spillways, and structures interacting with open surfaces. Maintaining Froude number similarity in river models is crucial, as it replicates surface flow features like wave patterns and velocities.
01:10Poiseuille's Law and Reynolds Number
Any fluid in a horizontal tube can flow due to pressure differences—fluid flows from high to low pressure. The flow rate (Q) is the ratio of pressure difference and resistance through a horizontal tube. The greater the pressure difference, the higher the flow rate. The flow resistance is expressed as:
01:22Couette Flow
Couette flow represents the flow of fluid between two parallel plates, with one plate fixed and the other moving with a constant velocity. This configuration allows for a simplified analysis using the Navier-Stokes equations, which govern fluid motion under conditions of viscosity and incompressibility. For Couette flow, the assumptions include a steady, laminar, incompressible flow with a zero-pressure gradient in the flow direction. This flow type is beneficial for understanding shear-driven...