| Autor: |
F.W. Chang, A.E. Dukler |
| Rok vydání: |
1964 |
| Předmět: |
|
| Zdroj: |
International Journal of Heat and Mass Transfer. 7:1395-1404 |
| ISSN: |
0017-9310 |
| DOI: |
10.1016/0017-9310(64)90127-9 |
| Popis: |
Approximate theoretical solutions have been obtained for laminar flow in a conduit with wavy moving boundaries. The results predict the data of Laird quite well and demonstrate that the oscillation of the boundary contributes to the apparent increased friction. This suggests that studies of the interface in two phase flow concern themselves not only with the wave profiles but with the wave frequency as well. The effect of a moving boundary in turbulent flow is shown to depend on the relative magnitude of the random fluctuation due to turbulence and the periodic fluctuation induced by the moving boundary. Experimental equipment is described in which turbulent intensity measurements were made across a wall oscillating with a standing wave having a length of 2 in and an amplitude of +0·025. Even with this large wavelength and low amplitude, the oscillating wall caused increased apparent turbulent shear stress. Because analytical solution of the equations of motion are not possible, an extension of the phenomenological method to the case of moving walls is outlined. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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