Cfd study on mixing performance in various microchannel geometries
| dc.contributor.author | Nurul Azrin Abdul Rahim | |
| dc.date.accessioned | 2021-05-10T05:36:10Z | |
| dc.date.available | 2021-05-10T05:36:10Z | |
| dc.date.issued | 2018-04-01 | |
| dc.description.abstract | Microreactor is an element of Process intensification (PI) where intensified equipment such as a microreactor requires the understanding of fundamental knowledge in order for it to be fully utilised. Mixing in microreactor is greatly influenced by its hydrodynamic behaviour and thus, increases the need to have insights on it. In micro-geometries, the fluid viscous effect becomes dominant, and micro-flow typically falls in the laminar regime. In the absence of turbulence, the fluid mixing becomes purely dependent on diffusion, which is a slow molecular process. On the other hand, in many chemical engineering processes, fast and complete mixing of relevant fluids is of crucial importance. The mixing quality may determine the performance of the whole microfluidic system and it is the most challenging problems which needs further exploration. In this work, fluid flow, mixing intensity (IM) and pressure drop of microchannels were investigated over a range of Reynolds number (0.1<Re<120) via three-dimensional Computational Fluid Dynamics (CFD) model. Two aspects of microchannel, inlet angles and types of grooves will be investigated in this research. The results obtained provide some insight of transport phenomena on mixing that occurred in a microchannel. T-shaped channel showed better mixing than Y- and Arrow-shaped channel at all Reynolds number (Re) tested and mixing intensity decreases with an increase of Re. T-shaped channel with inlet grooves showed far better mixing performance compared to T-shaped channel and T-shaped channel with outlet grooves as the IM for inlet grooves reached more than 0.8 at all Re tested. This is due to the inlet grooves that causes flow disruption and forms secondary flow or vortices, which led to an enlargement of the fluids interface for increased diffusion and residence time thereby causing greater mixing efficiency. T-channel and T-channel with outlet grooves reached IM less than 0.4 for Re>10 at the end of the mixing channel due to the absence of disruption in the flow field, thereby decreasing the mixing efficiency. In terms of time scale evaluation, diffusion is dominant at Re = 0.1 where the residence time is 3s and complete mixing is achieved for all the geometries. Compared to Re = 120 where the residence time is 0.0025s, advection is dominant and complete mixing only achieved in T-shaped channel with inlet grooves. The results also revealed that pressure drop is totally dependent on Re. The higher the Re, the higher the pressure drop for all micro channels, and T-shaped channel with inlet grooves exhibit the highest pressure drop compared to the other microchannels. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/13380 | |
| dc.language.iso | en | en_US |
| dc.title | Cfd study on mixing performance in various microchannel geometries | en_US |
| dc.type | Thesis | en_US |
Files
License bundle
1 - 1 of 1
Loading...
- Name:
- license.txt
- Size:
- 1.71 KB
- Format:
- Item-specific license agreed upon to submission
- Description: