In analogy with the work of Kawasaki and Oppenheim on the shear viscosity, the density expansion of the bulk viscosity is obtained for gas systems which interact with attractive forces and repulsive forces. In the case of repulsive forces, the first term in the density expansion of the bulk viscosity is of order ${\rho }^2$. In the case of attractive forces with bound states, the density expansion possesses a term of order $\rho$.

• Received 22 May 1970

DOI:https://doi.org/10.1103/PhysRevA.2.2153