DOI: 10.1615/ICHMT.2009.TurbulHeatMassTransf
ISBN Print: 978-1-56700-262-1
ISSN: 2377-2816
DNS investigation of heat transfer structures of turbulent boundary layer over forward-facing step
ABSTRACT
This paper presents observations and investigations of the detailed structure of a turbulent boundary layer over a forward-facing step. A turbulent boundary layer with reattachment and separation which causes an increase in friction of flow, heat-transfer rate and disturbance in transportation of scalar often occurs in fluid machinery, the atmosphere, etc. Thus, it is important for friction reduction, enhancement of heat transfer and environmental protection to know the transport phenomena of a boundary layer with reattachment and separation. Therefore, in order to investigate the detailed turbulent heat-transfer structures of a boundary layer over an obstacle which causes reattachment and separation, a DNS of the turbulent boundary layer with heat transfer over a forward-facing step is carried out. The present DNSs are conducted under conditions with various Reynolds numbers and wall thermal conditions, in which the effect of buoyancy is also considered. DNS results show the quantitative turbulent statistics and structures of boundary layers over a forward-facing step in both the velocity and the thermal fields.