entrainment (engineering)

{{short description|Entrapment of one substance by another substance}}

{{other uses|Entrainment (disambiguation)}}

In engineering, entrainment is the entrapment of one substance by another substance.{{cite book|editor=Perry, R.H.|editor2=Green, D.W.|title=Perry's Chemical Engineers' Handbook|edition=Sixth|publisher=McGraw-Hill|year=1984|isbn=0-07-049479-7}} For example:

• The entrapment of liquid droplets or solid particulates in a flowing gas, as with smoke.
• The entrapment of gas bubbles or solid particulates in a flowing liquid, as with aeration.
• Given two mutually insoluble liquids, the emulsion of droplets of one liquid into the other liquid, as with margarine.
• Given two gases, the entrapment of one gas into the other gas.
• "Air entrainment" – The intentional entrapment of air bubbles into concrete.
• Entrainment defect in metallurgy, as a result of folded pockets of oxide inside the melt.