Operator splitting for moment equations

Because the collision time t is arbitrary and can lead to stiff equations, it is best to solve Eq. (8.96) using operator splitting, i.e. solve first 

The collision term in Eq. (8.99) can be solved semi-analytically by setting 

Written in terms of the finite-volume moments on a uniform mesh, this formula becomes 

The moments result from solving Eq. (8.98) starting from and the equilibrium 

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