We study the homogenization problem for a diffusion process in a divergence-free random drift field. In particular, in case of a small Gaussian field we derive an asymptotic expansion of the effective diffusion matrix in terms of its spectral density.
"Homogenization of a Diffusion Process in a Divergence-Free Random Field." Ann. Probab. 16 (3) 1084 - 1126, July, 1988. https://doi.org/10.1214/aop/1176991679