Descrizione del progetto
Modellare il flusso dell’acqua attraverso la neve
La capacità dell’acqua di muoversi attraverso la neve influisce sulle inondazioni stagionali e sull’idrologia dei ghiacciai, ma può variare notevolmente a seconda della microstruttura della neve. Finanziato dal programma di azioni Marie Skłodowska-Curie, il progetto SnowMagnet ci aiuterà a comprendere meglio queste variazioni conducendo i primi studi sulla neve bagnata su scala dei pori mediante risonanza magnetica nucleare, insieme a modelli reticolari di Boltzmann e modelli reticolari a pori. I ricercatori otterranno informazioni sulle probabilità di spostamento dell’acqua liquida e le misure di diffusione. Studieranno la fusione e l’infiltrazione della neve utilizzando repliche porose delle geometrie della neve stampate in 3D e produrranno serie di dati sul flusso insaturo in funzione del numero di capillarità in mezzi modello e nella neve. L’obiettivo è fornire nuovi modelli che risolvano il trasporto dell’acqua nella neve.
Obiettivo
The effective hydraulic conductivity of snow is highly impacted by its microstructure, introducing a variability of at least three orders of magnitude, impacting seasonal flooding and glacier hydrology. Yet, the mechanisms of unsaturated flow and the impact of local phase transitions have never been investigated at the pore scale. This inhibits improving on the constitutive laws for larger scale models of snow hydrology using upscaling methods. Micro computer tomography is a very effective method for dry snow metamorphism but fails for wet snow because the transient flow and the accelerated change in microstructure cannot be resolved. We propose nuclear magnetic resonance (NMR) methods in combination with Lattice-Boltzmann simulations and Pore-Network models to characterize water flow in snow. Applying these methods on unsaturated flow in snow, we can resolve local saturation, liquid water displacement probabilities and diffusion measures, quantitatively measuring mechanisms of water transport. These are essential for gauging modelling approaches of transport phenomena. Whilst NMR methods have been used extensively on saturated flow, it has found limited application in unsaturated media and is poised for significant advances. To target melt and percolation phenomena in snow, we start with 3D printed porous media (single pores and fully resolved snow geometries) to refine the experimental setup and provide novel data for unsaturated flow in porous media. Assisted by Lattice-Boltzmann simulations we can link pore-scale mechanisms to the NMR data. The action will produce unique data sets on unsaturated flow as a function of capillary number in model porous media and snow. This data will be used to calibrate dynamic pore network models aiming at quantifying the transient flow in snow. This leads to a parameterization of effective hydraulic conductivity for a wide range of snow microstructures providing a new standard for models resolving water transport in snow.
Campo scientifico
Parole chiave
Programma(i)
- HORIZON.1.2 - Marie Skłodowska-Curie Actions (MSCA) Main Programme
Meccanismo di finanziamento
HORIZON-TMA-MSCA-PF-GF - HORIZON TMA MSCA Postdoctoral Fellowships - Global FellowshipsCoordinatore
7491 Trondheim
Norvegia