Abstract
Interfacial heat transport in open channel turbulent flows is strongly dependent on surface waves that can appear as a result of the interaction of bulk turbulence with the free surface. The paper describes wave/heat transfer phenomena in inclined turbulent open surface water flows. The experiments were conducted in a regime of transition from "weak" to "strong" turbulence, in which the stabilizing influences of gravity and surface tension are relatively small against the disturbing effects of turbulence. A key role of the Froude number, Fr⊥, built through the surface-normal component of g has been revealed. As Fr⊥ grows, the wave amplitude grows, and the frequency spectrum shifts towards shorter waves. These changes lead to a heat transfer improvement, enough to double the heat transfer coefficient. The experimental data have been compared with calculations based on a "K-ε" model. As a result, the range of applicability of the standard model has been established as Fr⊥<2000. The turbulent Prandtl number has been evaluated for Fr⊥<700.
| Original language | English |
|---|---|
| Pages (from-to) | 3765-3775 |
| Number of pages | 11 |
| Journal | International Journal of Heat and Mass Transfer |
| Volume | 46 |
| Issue number | 20 |
| DOIs | |
| State | Published - Sep 2003 |
| Externally published | Yes |
Funding
The authors would like to acknowledge the support of the APEX project through DOE Grant DE-FG03-86ER52123 and express their gratitude to Prof. T. Kunugi from Kyoto University, Japan and Prof. S. Banerjee and his group from UCSB for their valuable comments and discussions.
| Funders | Funder number |
|---|---|
| U.S. Department of Energy | DE-FG03-86ER52123 |
| University of California, Santa Barbara | |
| Kyoto University |
Keywords
- Free surface
- Heat transfer
- Turbulence
- Turbulent Prandtl number
- Waves