Interface stability of compressible fluids in porous media

The stability of flows in porous media plays a vital role in transiting energy supply from natural gas to hydrogen, especially for estimating the usability of existing underground gas storage infrastructures. Due to mixed gases inside storage, the interface stability of tangential-velocity discontinuity provides us the exact velocity rate in injecting and withdrawing natural gases effectively. Thus, this research aims to analyze the interface stability of the tangential-velocity discontinuity between two compressible gases by using Darcy's model to include the porosity effect. The results shown in this research will be a basis for considering whether underground gas storage in porous material can store hydrogen. We show the relation between the Mach number M, the viscosity mu, and the porosity epsilon on the stability of the interface. This interface stability affects gases' withdrawal and injection processes, thus will help us to determine the velocity with which gas can be extracted and injected into the storage effectively. By imposing solid walls along the flow direction, the critical values of these parameters regarding the stability of the interface are smaller than when considering no walls. The consideration of bounded flows approaches the problem more realistically. In particular, this analysis plays a vital role when considering two-dimensional gas flows in storages and pipes.

Automated summary

This research aims to analyze the interface stability of the tangential-velocity discontinuity between two compressible gases using Darcy's model and including the porosity effect, providing a basis for considering underground gas storage, particularly for storing hydrogen. The relation between Mach number M, viscosity mu, and porosity epsilon on the stability of the interface is shown to affect gases' withdrawal and injection processes, helping determine the velocity at which gas can be extracted and injected effectively for storage. Solid walls along the flow direction significantly impact the critical values of these parameters regarding the stability of the interface, with bounded flows providing a more realistic approach to the problem, especially in two-dimensional gas flows in storages and pipes.