  Five eigenvectors of the linear thermoviscous flow over the homogeneous
background derived for the quasi-plane geometry of the flow. The corresponding
projectors are calculated and applied to get the nonlinear evolution equations
for the interacting vortical and acoustic modes. Equation on streaming cased by
arbitrary acoustic wave is specified. The correspondence to the known results
on streaming cased by quasi-periodic source is traced. The radiation acoustic
force is calculated for the mono-polar source.
