Miah Md. Ashraful Alam

Characteristics of turbulent confined jets during fast filling of H2 tank at high pressure

This paper presents computational fluid dynamics (CFD) studies on turbulent confined jets of H2 gas during fast filling of a cylindrical tank at high pressure. The CFD model is validated by comparison with experimental results. An attempt is made to study the thermo-fluid dynamics of hydrogen gas alongside the characteristics of confined jets in the tank during filling. A pressure-velocity coupling algorithm is applied to solve the Favre averaged Navier-Stokes equations with an SST k-ω turbulence model. The real gas model using Redlich-Kwong equation of state is considered for density computation to model compressibility effects at high pressure. Convective heat transfer from the compressed gas to tank wall is estimated through the coupling between the energy equations of gas and solids. A standard type III, 74L hydrogen cylinder composed of aluminum and CFRP for liner and laminate is used in the present study.

Homogeneous Condensation in Supersonic Impinging Jets onto Cylindrical Cavity

Over half a century researchers have engaged themselves in doing research on supersonic impinging jets for their fundamental fluid dynamic perspectives as well as their huge practical applications. In a variety of engineering applications steam or moist air is used as working gas. Rapid expansion of steam or moist air leads to an occurrence of non-equilibrium homogeneous condensation at the region between downstream of nozzle exit and an obstacle. Surrounding gas is heated due to the release of latent heat of condensation, and may affect the jet flow features. The present numerical work deals with the effect of condensation on the aerodynamic and oscillatory flow features of supersonic impinging jets onto a cylindrical cavity. A TVD scheme is used to solve the RANS equations and droplet growth equations for simulating condensation in the jet flowfield. The numerical code is validated through comparison with experimental results. Predicted flow and oscillatory properties of jets are presented.