Detailed simulations of environmental fluid dynamics
Title: Detailed simulations of environmental fluid dynamics
DNr: NAISS 2024/5-358
Project Type: NAISS Medium Compute
Principal Investigator: Gaetano Sardina <>
Affiliation: Chalmers tekniska högskola
Duration: 2024-07-01 – 2025-07-01
Classification: 20306 10105


This proposal contains a medium-level request for computer time on high-performance computing (HPC) resources within the National Academic Infrastructure for Super-computing in Sweden (NAISS). The computational time will be used for the activities within different projects in the field of environmental fluid dynamics. In particular, most of the computations will be dedicated to the recently funded ERC consolidator grant MixClouds starting in June 2024 financed by the European Union. MixClouds will investigate the dynamics of mixed-phase clouds, atmospheric complex three-phase systems containing suspended ice, supercooled water droplets, and water vapor that are responsible for most of the precipitations reaching the Earth's surface. Despite their relevance, there is a lack of a basic understanding of the complex hydrodynamics, heat, and mass transfer between the different water components with numerous scientific open questions. In the last decades, many scientific works have shown a significant impact of turbulence in warm (ice-free) clouds and warm rain formation in enhancing condensation/evaporation of rain droplets and promoting collisions. On the other hand, the role of turbulence in mixed-phase clouds has never been properly quantified; consequently, up to now, this topic has been nearly exclusively a subject pertaining to atmospheric physics rather than fluid dynamics. The project will benefit from a combination ofnumerical tools developed for general multiphase flows at different scales. The final results can potentially generate a ground-breaking impact not only in the areas of turbulent multiphase flows and cloud physics but also in climatology and in all environmental and industrial applications involving suspensions of three-phase flows in the presence of phase changes. Other activities are related to projects funded by the Swedish Research Councils VR, FORMAS and the Swedish Energy Agency. The VR project will improve our knowledge of the microphysical processes in warm clouds (i.e. ice free) using numerical simulations with the objective to derive new stochastic models for droplet size distributions and implement them in an existing LES atmospheric solver. A FORMAS project is related to urban design and heat comfort in urban areas. The final results will provide new guidelines for sustainable urban design and evaluate the best strategies to enhance urban comfort. Another FORMAS projects are related to the transport of microplastics in marine environment and the absorbtion dynamics in green roof using pore-scale simulations. Finally, the project funded by the Sweadish Energy Agency, will investigate the design of novel reactors for carbone-dioxide capture and utilization. We aim to develop a multiphase mathematical model coupled with chemical reactions to design the new generations of industrial reactors to efficiently capture CO2.