학술논문
Turbulence Structure in Recovery Region of Pure Poiseuille, Pure Couette and Couette-Poiseuille Type Turbulent Flows over a Backward-Facing Step(Fluids Engineering) / 純粋ポアズイユ,純粋クエットおよびクエット・ポアズイユ型バックステップ乱流の回復域の乱流構造(流体工学,流体機械)
Document Type
Journal Article
Author
Source
日本機械学会論文集 B編 / Transactions of the Japan Society of Mechanical Engineers Series B. 2009, 75(759):2143
Subject
Language
Japanese
ISSN
0387-5016
1884-8346
1884-8346
Abstract
Turbulence statistics in velocity recovery region of pure Poiseuille, pure Couette and Couette-Poiseuille type turbulent channel flows over a backward-facing step are measured and investigated experimentally. The flows are turbulent channel flows between moving and stepside stationary walls with different non-dimensional upstream pressure gradients β_0 (flow type parameter). The channel expansion ratio is 1.50. The upstream Reynolds number based on the friction velocity and upstream channel half width is about 300. Regions for the logarithmic and half power velocity laws in the backward-facing step flows were specified in the last report. In this study, velocity profiles are measured by using X-type hot-wire anemometry at several sections and turbulence statistics at the sections are estimated. The region for the logarithmic velocity law appears in the regions aside the production predominant region. On the other hand, the region for the half power velocity law appears in the region where the turbulent diffusion term is comparable with the production term.