Comparison of Different Turbulence Models in Open Channels with Smooth-Rough Bedforms
The turbulence models play an important role in all types of computational fluid dynamics based numerical modelling. There is no universal turbulence model which can be applied in all the scenarios. Therefore, if a suitable closure model is used in a simulation work, only then the successful numeric...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Mehran University of Engineering and Technology
2013-04-01
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| Series: | Mehran University Research Journal of Engineering and Technology |
| Subjects: | |
| Online Access: | http://publications.muet.edu.pk/research_papers/pdf/pdf818.pdf |
| Summary: | The turbulence models play an important role in all types of computational fluid dynamics based numerical modelling. There is no universal turbulence model which can be applied in all the scenarios. Therefore, if a suitable closure model is used in a simulation work, only then the successful numerical modelling will be achieved. This paper presents the evaluation of three turbulence models in numerical modelling of open channel flows having beds comprising of two parallel strips, one being smooth and the other one being rough. The roughness on the rough side of the channel was created with the help of gravels. The turbulence models tested for their suitability in this case were Reynolds stress model, k-?model and RNG based k-?model. A structured mesh was used in this simulation work. Grid independence test was also conducted in the simulation. The evaluation of the turbulence models was made through the primary velocity contours and secondary velocity vectors over the cross section of the channel. It was revealed that Reynolds stress model simulated the flow behaviour successfully and results obtained through this model matched very closely to that of the experimental data whereas k-?model and RNG based k-? model failed to reproduce the flow field successfully. These results will be helpful for CFD (Computational Fluid Dynamics) modellers in correct selection of the turbulence model in these types of channels |
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| ISSN: | 0254-7821 2413-7219 |