A regularization strategy for discontinuity when modelling coupled water and heat flow in freezing unsaturated soil

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60460709%3A41330%2F24%3A100795" target="_blank" >RIV/60460709:41330/24:100795 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1016/j.compfluid.2024.106299" target="_blank" >https://doi.org/10.1016/j.compfluid.2024.106299</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.compfluid.2024.106299" target="_blank" >10.1016/j.compfluid.2024.106299</a>

Jazyk výsledku

angličtina

Název v původním jazyce

A regularization strategy for discontinuity when modelling coupled water and heat flow in freezing unsaturated soil

Popis výsledku v původním jazyce

Freezing tightly couples the water and heat flow. In most porous media, the interface between liquid and frozen water is not sharp and a slushy zone is present. There are two distinct approaches for mathematical modelling of freezing. It is the equilibrium approach which allows an instant freezing under given conditions and non -equilibrium approach where a specific timing in the freezing process is considered. In this contribution, we specifically target the equilibrium approach . The key mathematical model for the equilibrium approach is the Clausius-Clapeyron equation, which allows the derivation of a soil freezing curve relating temperature to pressure head. Implementing freezing soil accurately is not a straight -forward. Using the Clausius-Clapeyron equation creates a discontinuity in the freezing rate and latent heat at the freezing point. Little attention has been paid to the adequate description of the numerical treatment of this phenomenon and to the computational challenges that it poses. Numerical approximation of this discontinuous system is prone to spurious oscillations. In this contribution, we show the application of regularization of the discontinuous term. This treatment successfully stabilizes the computation and can remove oscillations. To avoid over -regularization, we present here a minimax strategy to determine optimal regularization parameters. We further compare an over -regularized setup with the non -equilibrium approach , where we show that a successful regularization is equivalent to incorporating a minimal timing to the freezing process. Finally - for validating our implementation and computational approach - experimental laboratory data of the volumetric water content and temperature profiles from previously published soil freezing experiments were represented here with the optimally regulized equilibrium approach .

Název v anglickém jazyce

A regularization strategy for discontinuity when modelling coupled water and heat flow in freezing unsaturated soil

Popis výsledku anglicky

Freezing tightly couples the water and heat flow. In most porous media, the interface between liquid and frozen water is not sharp and a slushy zone is present. There are two distinct approaches for mathematical modelling of freezing. It is the equilibrium approach which allows an instant freezing under given conditions and non -equilibrium approach where a specific timing in the freezing process is considered. In this contribution, we specifically target the equilibrium approach . The key mathematical model for the equilibrium approach is the Clausius-Clapeyron equation, which allows the derivation of a soil freezing curve relating temperature to pressure head. Implementing freezing soil accurately is not a straight -forward. Using the Clausius-Clapeyron equation creates a discontinuity in the freezing rate and latent heat at the freezing point. Little attention has been paid to the adequate description of the numerical treatment of this phenomenon and to the computational challenges that it poses. Numerical approximation of this discontinuous system is prone to spurious oscillations. In this contribution, we show the application of regularization of the discontinuous term. This treatment successfully stabilizes the computation and can remove oscillations. To avoid over -regularization, we present here a minimax strategy to determine optimal regularization parameters. We further compare an over -regularized setup with the non -equilibrium approach , where we show that a successful regularization is equivalent to incorporating a minimal timing to the freezing process. Finally - for validating our implementation and computational approach - experimental laboratory data of the volumetric water content and temperature profiles from previously published soil freezing experiments were represented here with the optimally regulized equilibrium approach .

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10503 - Water resources

Projekt

<a href="/cs/project/LTE119008" target="_blank" >LTE119008: Vývoj inovativních klimatických (monitorovacích a varovných) systémů pro efektivní management živin a vody v půdě v rámci spolupráce EU-CELAC</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

COMPUTERS & FLUIDS

ISSN

0045-7930

e-ISSN

0045-7930

Svazek periodika

277

Číslo periodika v rámci svazku

106299

Stát vydavatele periodika

CZ - Česká republika

Počet stran výsledku

13

Strana od-do

1-13

Kód UT WoS článku

001243399800001

EID výsledku v databázi Scopus

2-s2.0-85193294753