DOI: 10.1615/THMT-18
ISBN Print: 978-1-56700-468-7
ISBN Online: 978-1-56700-467-0
ISSN Print: 2377-2816
DNS Study on Characteristics and Structures of Turbulent Heat Transfer in Thermally-Stratified Boundary Layer over 2D Hill
摘要
The subject of this study is to reveal turbulent heat transfer phenomena in a thermally-stratified boundary layer over 2-dimensional (2D) hill, direct numerical simulation (DNS) is carried out. In this study, effects of both a ratio of hill height to boundary layer thickness and a thermal stratification are mainly explored, in which characteristic tendencies of recirculation region are observed in results of DNS with various thermal stratification and height of 2D hill. Thus, characteristics and structures of turbulent heat transfer phenomena in a thermally-stratified boundary layer over 2D hill are revealed in detail. Also, influences of turbulent state around top of the hill to the recirculation region are especially investigated and observed. In particular, the counter gradient diffusion phenomenon (CDP) occurs due to both hill shape and stable thermal stratification, but no influence of CDP to the recirculation region is found.