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Boussinesq approximation

Boussinesq approximation

Boussinesq approximation is a method to approximate buoyancy caused by temperature difference in incompressible fluid.

Using Boussinesq approximation, buoyancy caused by changes in density is expressed with the following equation:

ρ: Density for reference temperature [kg/m3]
g : Gravitational acceleration [m/s2]
β : Coefficient of thermal expansion [1/K]
: Temperature [K]
T: Reference temperature [K]


When temperature change is large and momentum change accompanying density change is too big to ignore, approximation error difference becomes large.

Boussinesq approximation is named after a French physicist Joseph Valentin Boussinesq.