70th Annual Meeting of the APS Division of Fluid Dynamics (November 19, 2017 — November 21, 2017)

V0048: Hydrodynamic and thermal turbulent structures in laminarescent boundary layers

Authors

• Guillermo Araya, University of Puerto Rico at Mayaguez, PR, USA
• Gabriel Torres, University of Puerto Rico at Mayaguez, PR, USA
• Guillermo Marin, Barcelona Supercomputing Center, Barcelona, Spain
• Fernando Cucchietti, Barcelona Supercomputing Center, Barcelona, Spain

DOI: https://doi.org/10.1103/APS.DFD.2017.GFM.V0048

High spatial/temporal resolution Direct Numerical Simulation (DNS) of a spatially-developing turbulent boundary layer with a passive scalar is performed. The initial turbulent flow in a zero pressure gradient (ZPG) boundary layer is subjected to a very strong favorable pressure gradient (FPG). The strong acceleration prescribed to the turbulent flow induces “quasi-laminarization”. While evident “signatures” of the strong FPG have been identified in the velocity field, “signatures” are less obvious in the temperature field; particularly, the thermal transport does not seem to be strongly affected by the “quasi-laminarization” process. The strong FPG is a source of dissimilarity between the momentum and thermal transport, causing a breakdown of the Reynolds analogy.