Diffusion and convection of species, governed by Fick's law.
Species move by diffusion (Fick's law J=-D dC/dx) and convection. Mass transfer analogies to heat (Sherwood number Sh, Schmidt number Sc). Applies in drying, humidification, absorption, evaporation and membrane separations.
Perfume spreads in still air by diffusion over minutes.
Mass transfer describes how species move by diffusion and convection, which matters for drying, evaporation, membranes and fuel cells.
Diffusion and convection of species, governed by Fick's law.
Mass transfer describes how species move by diffusion and convection, which matters for drying, evaporation, membranes and fuel cells.
The diffusion flux of a species is proportional to the negative gradient of its concentration, with the diffusion coefficient as the constant.
Both have driving forces and resistances, and analogies such as the Chilton-Colburn relation link their coefficients.
Typical applications include estimating the evaporation rate of water from a drying surface, designing a membrane separation of gases and predicting the mixing of pollutants in an air stream.
Study "Building thermal analysis" first (topic 98 of 105 in Thermodynamics & Fluids). It covers the groundwork this topic builds on.
Diffusion coefficient D. Evaporation from water surfaces. Lewis number.
Perfume spreads in still air by diffusion over minutes.
The next topic is "Cryogenics", which builds directly on this one.
It is classed as Advanced in Thermodynamics & Fluids (topic 99 of 105). It is an advanced topic. It assumes you are comfortable with the intermediate topics in Thermodynamics & Fluids.
Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.