Okuzeka
Chemical Engineering vocabulary · Fluid Flow, Pumps and Piping

Viscosity

Meaning in chemical engineering, with examples

/vɪˈskɑːsəti/nounCore term

In chemical engineering, viscosity means: A fluid's resistance to flow: honey has a high value, water a low one. Measured in pascal-seconds or, more often in practice, centipoise (cP).

In Turkish: viskozite, akmazlık

How it is used

Used in pump selection, pipe sizing, mixing and quality control. Viscosity falls as liquids get hotter, which is why heavy oils and resins are kept warm. Water at 20 °C has a viscosity of about 1 cP.

Example sentences

  1. The resin's viscosity is too high at room temperature, so the line is steam-traced.

  2. As viscosity rises, the centrifugal pump loses head and efficiency.

Common collocations

  • high viscosity
  • dynamic viscosity
  • kinematic viscosity
  • viscosity measurement
  • Reynolds numberA dimensionless number (Re = ρvD/μ) that compares inertial forces with viscous forces and tells you whether flow is laminar or turbulent.
  • pressure dropThe loss of pressure as a fluid flows through a pipe, valve, filter, bed or piece of equipment, caused mainly by friction.
  • laminar flowSmooth flow in which fluid moves in parallel layers with little mixing between them. In pipes it happens at low Reynolds numbers, typically below about 2,100.
  • pumpA machine that moves a liquid through pipes by adding pressure to it. Most plant pumps are centrifugal; others are positive displacement types such as gear or diaphragm pumps.

This word in other fields

The same English word can have a different meaning in another field:

More terms: Fluid Flow, Pumps and Piping

Practise with graded reading

Reading at the right level is the fastest way to make new words stick. Pick free English books by level: