Direct numerical simulation of rough-wall heat transfer in a turbulent channel flow

✍ Scribed by Yutaka Miyake; Koichi Tsujimoto; Masaru Nakaji

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 722 KB
• Volume: 22
• Category: Article
• ISSN: 0142-727X
• DOI: 10.1016/s0142-727x(01)00085-6

✦ Synopsis

Heat transfer in a channel of rough wall is simulated in this work. Two kinds of roughness are considered, i.e., one assumes sandgrain roughness based on roughness model and the other regularly arranged two-dimensional ribs. No models other than sand-grain roughness implemented in the simulation. For the sake of computational load, one wall is assumed to be smooth and the global Reynolds number Re s based on mean friction velocity and half channel width is 150. Mean ¯ow property of velocity and thermal ®elds are found to be little in¯uenced by the property of roughness elements but depends on total drag, except for in the layer close to the wall where direct interference with roughness elements manifests itself. Similarity of thermal ®eld with velocity one is con-®rmed for the low Prandtl number ¯ows considered in the work. The mixing is found to be controlled by large scale motion which is inherent to the logarithmic layer, getting closer to the wall.