We study dusty winds driven by radiation pressure in the atmosphere of a rapidly star-forming environment .
We apply the variable Eddington tensor algorithm to re-examine the two-dimensional radiation hydrodynamic problem of a column of gas that is accelerated by a constant infrared radiation flux .
In the absence of gravity , the system is primarily characterized by the initial optical depth of the gas .
We perform several runs with different initial optical depth and resolution .
We find that the gas spreads out along the vertical direction , as its mean velocity and velocity dispersion increase .
In contrast to previous work using flux-limited diffusion algorithm , we find little evolution in the trapping factor .
The momentum coupling between radiation and gas in the absence of gravity is similar to that with gravity .
For Eddington ratio increasing with the height in the system , the momentum transfer from the radiation to the gas is not merely \sim L / c , but amplified by a factor of 1 + \eta \tau _ { IR } , where \tau _ { IR } is the integrated infrared optical depth through the system , and \eta \sim 0.5 - 0.9 , decreasing with the optical depth .
We apply our results to the atmosphere of galaxies and conclude that radiation pressure may be an important mechanism for driving winds in the most rapidly star-forming galaxies and starbursts .