On the Oberbeck-Boussinesq approximation Academic Article uri icon


  • This paper deals with a derivation (using a perturbation technique) of an approximation, due to Oberbeck8,9 and Boussinesq,1 to describe the thermal response of linearly viscous fluids that are mechanically incompressible but thermally compressible. The present approach uses a nondimensionalization suggested by Chandrasekhar2 and utilizing the ratio of two characteristic velocities as a measure of smallness, systematically derives the Oberbeck-Boussinesq approximation as a third-order perturbation. In the present approach, the material is subjected to the constraint that the volume change is determined solely by the temperature change in the body and uses a novel approach in deriving the thermodynamical restrictions. Consequently, it is free from the additional assumptions usually added on in earlier works in order to obtain the correct equations.

published proceedings


altmetric score

  • 2.5

author list (cited authors)

  • Rajagopal, K. R., Ruzicka, M., & Srinivasa, A. R.

citation count

  • 170

complete list of authors

  • Rajagopal, KR||Ruzicka, M||Srinivasa, AR

publication date

  • December 1996