A Dynamic and Fully Implicit Non‐Isothermal, Two‐Phase, Two‐Component Pore‐Network Model Coupled to Single‐Phase Free Flow for the Pore‐Scale Description of Evaporation Processes

Weishaupt, Kilian; Helmig, Rainer

doi:10.1029/2020wr028772

Cited by 12 publications

(30 citation statements)

References 64 publications

(95 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We extend the fully implicit, dynamic two-phase pore-network model described in [21], based on the work of [22] and [23]. Joekar-Niasar et al [22] developed a dynamic two-phase pore-network model which is accounting for the dynamics of phase displacement processes.…”

Section: Two-phase Pore-network Modelmentioning

confidence: 99%

“…Qin [23] describes an extension of this concept to account for vapor transport. Weishaupt et al [21] present a pore-network model coupled to a free flow domain which allows vapor transfer across the interface. We consider two-phase flow without component transport.…”

Section: Two-phase Pore-network Modelmentioning

confidence: 99%

“…Following [21], the volume flux Q ij from pore body i to a neighboring pore body j via the pore throat ij is approximated using a Hagen-Poiseuille-type flow for each phase α…”

Section: Momentum Balancementioning

confidence: 99%

“…The interface pores are chosen to be large enough to contain the maximum drop volume until the drop detachment. To be consistent with the pore-network model [21,22], we define the contact angle to be measured in the gas phase.…”

Section: Drop Formulation In the Channelmentioning

confidence: 99%

See 3 more Smart Citations

Two-phase flow dynamics at the interface between GDL and gas distributor channel using a pore-network model

Michalkowski¹,

Veyskarami²,

Bringedal³

et al. 2022

Preprint

View full text Add to dashboard Cite

For improved operating conditions of a polymer electrolyte membrane (PEM) fuel cell, a sophisticated water management is crucial. Therefore, it is necessary to understand the transport mechanisms of water throughout the cell constituents especially on the cathode side, where the excess water has to be removed. Pore-scale modeling of diffusion layers and gas distributor has been established as a favorable technique to investigate the ongoing processes. Investigating the interface between the cathode layers, a particular challenge is the combination and interaction of the multi-phase flow in the porous material of the gas diffusion layer (GDL) with the free flow in the gas distributor channels. The formation, growth and detachment of water droplets on the hydrophobic, porous surface of the GDL have a major influence on the mass, momentum and energy exchange between the layers. A dynamic pore-network model is used to describe the flow through the porous GDL on the pore-scale. To capture the droplet occurrence and its influence on the flow, this dynamic two-phase pore-network model is extended to capture droplet formation and growth at the surface of the GDL as well as droplet detachment due to the gas flow in the gas distributor channels. In this article, the developed model is applied to single-and multi-tube systems to investigate the general drop behavior. These rather simple test-cases are compared to experimental and numerical data available in the literature. Finally, the model is applied to a GDL unit cell to analyse the interaction between two-phase flow through the GDL and drop formation at the interface between GDL and gas distributor channel.

show abstract

Section: Two-phase Pore-network Modelmentioning

confidence: 99%

Section: Two-phase Pore-network Modelmentioning

confidence: 99%

“…Following [21], the volume flux Q ij from pore body i to a neighboring pore body j via the pore throat ij is approximated using a Hagen-Poiseuille-type flow for each phase α…”

Section: Momentum Balancementioning

confidence: 99%

Section: Drop Formulation In the Channelmentioning

confidence: 99%

See 2 more Smart Citations

Two-phase flow dynamics at the interface between GDL and gas distributor channel using a pore-network model

Michalkowski¹,

Veyskarami²,

Bringedal³

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

“…The hydrophobic domain (GDL in Fig. 1, domain I) is represented by a pore-network model following the approach developed by Weishaupt et al [25]. The model is extended enabling the modeling of hydrophobic-hydrophilic fluid interactions at the interface, which is shown by the red dashed line in Fig.…”

Section: Model Conceptsmentioning

confidence: 99%

Modeling of two phase flow in a hydrophobic porous medium interacting with a hydrophilic structure

Michalkowski¹,

Weishaupt²,

Schleper³

et al. 2022

Preprint

View full text Add to dashboard Cite

Fluid flow through layered materials with different wetting behavior is observed in a wide range of applications in biological, environmental and technical systems. Therefore, it is necessary to understand the occuring transport mechanisms of the fluids at the interface between the layered constituents. Of special interest is the water transport in polymer electrolyte membrane fuel cells (PEM FC). Here, it is necessary to understand the transport mechanisms of water throughout the cell constituents especially on the cathode side, where the excess water has to be removed. This is crucial to choose optimal operating conditions and improve the overall cell performance. Pore-scale modeling of gas diffusion layers (GDLs) and gas distributor has been established as a favorable technique to investigate the ongoing processes. Investigating the interface between the hydrophobic porous GDL and the hydrophilic gas distributor, a particular challenge is the combination and interaction of the different material structures and wetting properties at the interface and its influence on the flow. In this paper, a modeling approach is presented which captures the influence of a hydrophilic domain on the flow in a hydrophobic porous domain at the interface between the two domains. A pore-network model is used as the basis of the developed concept which is extended to allow the modeling of mixed-wet interactions at the interface. The functionality of the model is demonstrated using basic example configurations with one and several interface pores and it is applied to a realistic GDL representation in contact with a channel-land structured gas distributor.

show abstract

Two-phase Flow Dynamics at the Interface Between GDL and Gas Distributor Channel Using a Pore-Network Model

et al. 2022

View full text Add to dashboard Cite

For improved operating conditions of a polymer electrolyte membrane (PEM) fuel cell, a sophisticated water management is crucial. Therefore, it is necessary to understand the transport mechanisms of water throughout the cell constituents especially on the cathode side, where the excess water has to be removed. Pore-scale modeling of diffusion layers and gas distributor has been established as a favorable technique to investigate the ongoing processes. Investigating the interface between the cathode layers, a particular challenge is the combination and interaction of the multi-phase flow in the porous material of the gas diffusion layer (GDL) with the free flow in the gas distributor channels. The formation, growth and detachment of water droplets on the hydrophobic, porous surface of the GDL have a major influence on the mass, momentum and energy exchange between the layers. A dynamic pore-network model is used to describe the flow through the porous GDL on the pore-scale. To capture the droplet occurrence and its influence on the flow, this dynamic two-phase pore-network model is extended to capture droplet formation and growth at the surface of the GDL as well as droplet detachment due to the gas flow in the gas distributor channels. In this article, the developed model is applied to single- and multi-tube systems to investigate the general drop behavior. These rather simple test-cases are compared to experimental and numerical data available in the literature. Finally, the model is applied to a GDL unit cell to analyze the interaction between two-phase flow through the GDL and drop formation at the interface between GDL and gas distributor channel.

show abstract

A Dynamic and Fully Implicit Non‐Isothermal, Two‐Phase, Two‐Component Pore‐Network Model Coupled to Single‐Phase Free Flow for the Pore‐Scale Description of Evaporation Processes

Abstract: Coupled system of free flow above a permeable medium appear in a wide range of technical and environmental applications. Prominent examples including two-phase flow range from fuel-cell water manage-

Cited by 12 publications

References 64 publications

Two-phase flow dynamics at the interface between GDL and gas distributor channel using a pore-network model

Two-phase flow dynamics at the interface between GDL and gas distributor channel using a pore-network model

Modeling of two phase flow in a hydrophobic porous medium interacting with a hydrophilic structure

Two-phase Flow Dynamics at the Interface Between GDL and Gas Distributor Channel Using a Pore-Network Model

Contact Info

Product

Resources

About