Direct Numerical Simulations of the Turbulence Evolution in a Uniformly Sheared and Stably Stratified Flow

Author(s)

Frank G. Jacobitz, University of San DiegoFollow
Sutanu Sarkar, University of California - San Diego
Charles W. Van Atta, University of California - San Diego

Document Type

Article

Publication Date

7-1997

Disciplines

Aerodynamics and Fluid Mechanics | Engineering

Abstract

Direct numerical simulations (DNS) are performed to investigate the evolution of turbulence in a uniformly sheared and stably stratified flow. The spatial discretization is accomplished by a spectral collocation method, and the solution is advanced in time with a third-order Runge–Kutta scheme. The turbulence evolution is found to depend strongly on at least three parameters: the gradient Richardson number Ri, the initial value of the Taylor microscale Reynolds numberRe_λ, and the initial value of the shear number SK/K is found to follow approximately an exponential law. The shear number SK/Re_λ indicated that the turbulence growth rate tends to become insensitive to Re_λ at the higher end of the Re_λ range studied here. The dependence of the critical Richardson number Ri_cr, which separates asymptotic growth of the turbulent kinetic energy K from asymptotic decay, on the initial values of the Reynolds number Re_λ and the shear number SK/0.04<Ri_cr

Digital USD Citation

Jacobitz, Frank G.; Sarkar, Sutanu; and Van Atta, Charles W., "Direct Numerical Simulations of the Turbulence Evolution in a Uniformly Sheared and Stably Stratified Flow" (1997). School of Engineering: Faculty Scholarship. 4.
https://digital.sandiego.edu/engineering_facpub/4