Related Experiment Video
Updated: Mar 2, 2026
11:19
Measuring Carbon-based Contaminant Mineralization Using Combined CO2 Flux and Radiocarbon Analyses
Published on: October 21, 2016
12.4K
A gas flow model for layered landfills with vertical extraction wells
Shi-Jin Feng1, Qi-Teng Zheng2, Hai-Jian Xie3
1Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China; Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092, China.
Waste Management (New York, N.Y.)
|May 13, 2017
Summary
This study models layered landfills with vertical wells, simplifying gas recovery by reducing 7 variables to 3 dimensionless ones. This advances landfill design and understanding of waste non-homogeneity effects on gas extraction.
Area of Science:
- Environmental Engineering
- Geotechnical Engineering
- Chemical Engineering
Background:
- Landfill gas recovery is crucial for renewable energy and environmental protection.
- Waste non-homogeneity (gas generation, permeability, temperature) complicates gas extraction modeling.
- Existing models often oversimplify complex landfill structures and well conditions.
Purpose of the Study:
- To develop a 2D axisymmetric analytical model for layered landfills with vertical wells.
- To investigate the impact of well boundary conditions and gas extraction on recovery efficiency.
- To simplify the analysis of double-layer landfill systems (waste and cover) by reducing independent variables.
Main Methods:
- Developed a two-dimensional axisymmetric analytical model for layered landfills.
- Utilized a horizontal layered structure to represent waste non-homogeneity.
- Transformed governing equations to dimensionless forms and solved using eigenfunction expansion.
- Investigated effects of boundary conditions and gas extraction parameters.
Main Results:
- A constant vacuum pressure boundary condition adequately represents perforated wells.
- Reduced 7 independent variables for a double-layer system into 3 dimensionless parameters.
- Demonstrated that different combinations of variables can yield similar gas recovery efficiencies.
- Quantitatively characterized the influence of these variables on gas recovery.
Conclusions:
- The simplified dimensionless parameters facilitate preliminary landfill design.
- The model effectively accounts for waste non-homogeneity in gas recovery analysis.
- This work represents an advance in modeling landfill gas extraction efficiency.
Related Concept Videos
01:23Plane Potential Flows
1.0K
Plane potential flows simplify fluid motion by assuming the fluid to be irrotational and incompressible. These characteristics allow these flows to be described by a velocity potential function, ϕ, representing the flow speed in a given direction, and a stream function, ψ, that visualizes the flow path, both governed by Laplace's equation. These parameters help in estimating flow patterns, velocity distributions, and pressure fields around various hydraulic structures.
Uniform...
Uniform...
1.0K
01:29Gradually Varying Flow
485
Gradually varying flow (GVF) in open channels describes situations where water depth changes slowly along the channel due to factors like non-uniform bed slope, channel shape variations, or obstructions. This flow type occurs when the depth adjusts gradually to balance gravitational forces, shear forces, and energy requirements, resulting in a low rate of depth change.Characteristics of Gradually Varying FlowGVF is commonly observed in natural streams, rivers, and canals, where flow depth...
485
01:17Steady, Laminar Flow Between Parallel Plates
925
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.
925
01:30Underflow Gates
462
Underflow gates are vital for controlling water flow in irrigation canals. The three main types of underflow gates — vertical, radial, and drum gates — serve different purposes while ensuring effective flow management. Vertical gates move up and down, generating a free-flowing water jet; radial gates pivot to regulate the flow; and drum gates rotate for precise adjustments. The flow through these gates is influenced by downstream conditions, resulting in free or drowned outflow.Free and...
462