Porochemothermoelastic solutions considering fully coupled thermo-hydro-mechanical-chemical processes to analyze the stability of inclined boreholes in chemically active porous media

We present new random walk methods to solve flow and transport problems in saturated/unsaturated porous media, including coupled flow and transport processes in soils, heterogeneous systems modeled through random hydraulic conductivity and recharge fields, processes at the field and regional scales. The numerical schemes are based on global random walk algorithms (GRW) which approximate the solution by moving large numbers of computational particles on regular lattices according to specific random walk rules. To cope with the nonlinearity and the degeneracy of the Richards equation and of the coupled system, we implemented the GRW algorithms by employing linearization techniques similar to the L-scheme developed in finite element/volume approaches. The resulting GRW L-schemes converge with the number of iterations and provide numerical solutions that are first-order accurate in time and second-order in space. A remarkable property of the flow and transport GRW solutions is that they are practically free of numerical diffusion. The GRW solvers are validated by comparisons with mixed finite element and finite volume solvers in one- and two-dimensional benchmark problems. They include Richards' equation fully coupled with the advection-diffusion-reaction equation and capture the transition from unsaturated to saturated flow regimes. &#160;For completeness, we also consider decoupled flow and transport model problems for saturated aquifers.

Download Full-text

Thermo-Hydro-Mechanical-Chemical Processes in Fractured Porous Media: Modelling and Benchmarking

10.1007/978-3-319-68225-9 ◽

2018 ◽

Cited By ~ 5

Keyword(s):

Porous Media ◽

Chemical Processes ◽

Fractured Porous Media

Download Full-text

Experimental Analysis of Biogas Combustion With Different Foam Materials in a Porous Media Burner

Volume 2: Combustion, Fuels, and Emissions; Renewable Energy: Solar and Wind; Inlets and Exhausts; Emerging Technologies: Hybrid Electric Propulsion and Alternate Power Generation; GT Operation and Maintenance; Materials and Manufacturing (Including Coatings, Composites, CMCs, Additive Manufacturing); Analytics and Digital Solutions for Gas Turbines/Rotating Machinery ◽

10.1115/gtindia2019-2667 ◽

2019 ◽

Author(s):

Sangjukta Devi ◽

Niranjan Sahoo ◽

P. Muthukumar

Keyword(s):

Porous Media ◽

Energy Efficient ◽

Combustion Zone ◽

Load Range ◽

Preheat Zone ◽

Power Intensity ◽

Stable Operating ◽

Operating Limits ◽

The Stability ◽

Porous Media Burner

Abstract The existing biogas Conventional Burners (CBs) are less energy efficient and are designed for rich fuel combustion. Porous Media Burner (PMB), working on the principle of combustion in porous media offer several advantages including high thermal efficiency, low emissions, high power intensity, etc. In this work, a study on the effect of porous material on the thermal behaviour of a biogas operated PMB is presented. A state-of-the-art PMB working in the thermal load range of 5 to 10 kW has been developed, which can be used for both industrial and domestic purposes. It is a two section burner composed of a combustion zone and a preheat zone. Keeping the material of the preheat zone unchanged (Al2O3 ceramic), the burner is tested with two different materials in the combustion zone (SiC and ZrO2 foams). Experimental investigation has been done to analyze the stability criteria and study the temperature distribution in the PMB. This includes the identification of the stable operating limits (flashback and blow off) and measurement of temperature profiles in axial and radial direction. These assessments confirm that SiC is a better choice over ZrO2 for lean biogas combustion in PMB.

Download Full-text