Preconditions and limitations of the postulate of scalar-dissipation-conductivity independence in a variable conductivity medium. Academic Article uri icon

abstract

  • Classical turbulent mixing paradigm--ingrained in scaling laws and closure models--is revisited in a variable-conductivity inhomogeneous medium. We perform direct numerical simulations to study the evolution of a passive scalar (temperature) field in a fluid with large conductivity gradients and investigate the behavior of scalar dissipation, conditional scalar dissipation, and velocity-to-scalar time scale ratio. Subject to the conditions of the investigation, it is found that these mixing characteristics become reasonably insensitive to conductivity after about one-third eddy turnover time. While the results support the classical paradigm, important preconditions and limitations are clearly identified.

published proceedings

  • Phys Rev E Stat Nonlin Soft Matter Phys

author list (cited authors)

  • Kumar, G., Girimaji, S. S., & Kerimo, J.

citation count

  • 1

complete list of authors

  • Kumar, Gaurav||Girimaji, Sharath S||Kerimo, Johannes

publication date

  • October 2011