Liquid distributions in unsaturated porous media under different gravitational accelerations and corresponding macroscopic gaseous diffusion coefficients were investigated to enhance understanding of plant growth conditions in microgravity. We used a single-component, multiphase lattice Boltzmann code to simulate liquid configurations in two-dimensional porous media at varying water contents fo...

We present useful expressions predicting the filling time of gaseous species inside photonic crystal fibers. Based on the theory of diffusion, this gas-filling model can be applied to any given fiber geometry or length by calculating diffusion coefficients. This was experimentally validated by monitoring the filling process of acetylene gas in several fiber samples of various geometries and len...

This paper presents helpful expressions predicting the filling time of gaseous species inside photonic crystal fibres. Based on the theory of diffusion, our gas-filling model can be applied to any given fibre geometry or length by calculating diffusion coefficients. This was experimentally validated by monitoring the filling process of acetylene gas in several fibre samples of various geometrie...

diffusion flame in a dust cloud combustion in a counterflow configuration is investigated in this research. it is presumed that the fuel particles vaporize first to yield a gaseous fuel to oxidize with the gas phase. the reaction rate is assumed to be of the arrhenius type. conservation equations for the non-unity lewis number are solved and the flame temperature with the variations of differen...

the premixed counterflow flames propagation in combustion of mixture which is a uniform mixture of fuel particles and air is analytically studied. this analysis framework is based on thermal-diffusion model with assumption that the lewis number is unit and the strain rate is constant. velocity profile is assumed as a function of one variable like x. the structure of the flame is presumed to con...

Whether steady-state gaseous microgravity spherical diffusion exist in the presence of radiation heat loss is an important fundamental question and has implications for spacecraft fire safety. In this work, experiments aboard International Space Station a transient numerical model are used to investigate existence flames. Gaseous flames stabilized on porous burner employed normal (i.e., fuel fl...