Effect of insoluble surfactant on turbulent bubbly flows in vertical channels
| Autor: | Metin Muradoglu, Gretar Tryggvason, Jiacai Lu |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Fluid Flow and Transfer Processes
Vertical channel Materials science Turbulence Mechanical Engineering General Physics and Astronomy Mechanics 01 natural sciences 010305 fluids & plasmas Volumetric flow rate Physics::Fluid Dynamics 010101 applied mathematics Lift (force) Pulmonary surfactant 0103 physical sciences 0101 mathematics Pressure gradient |
| Zdroj: | International Journal of Multiphase Flow. 95:135-143 |
| ISSN: | 0301-9322 |
| DOI: | 10.1016/j.ijmultiphaseflow.2017.05.003 |
| Popis: | The effect of an insoluble surfactant on the structure of turbulent bubbly upflow in a vertical channel is examined by direct numerical simulations (DNS). For nearly spherical bubbles the presence of a surfactant reduces the lateral lift on the bubbles and changes the structure of the flow in major ways. Clean bubbles are driven to the walls by the lift force and the void fraction distribution has a well defined peak near the walls, resulting in significant reduction in flow rate. Bubbles with strong enough surfactants do not experience significant lateral lift and remain in the bulk flow. Indeed, when surfactant is present the addition of bubbles to a turbulent flow has relatively little effect on the flow, once the pressure gradient is adjusted to account for the reduced weight of the mixture. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect