碩士 / 國立中正大學 / 機械工程系研究所 / 107 / This paper uses ANSYS Fluent to perform self-adjusting blade coating CFD simulation for fluid analysis of the bow wave region generated before the blade. Referring to the fluid model of the existing blade-coating literature, the blade-coating bow wave fluid model is established, assuming two-dimensional flow field. The boundary conditions at the inlet and the outlet are respectively equal to zero, and the contact with the moving substrate with the non-slip boundary condition and the contact of the blade is also a non-slip boundary condition. Under the condition of ignoring air shear force and liquid surface tension, the boundary condition of fluid free surface shearing force and positive force is zero. Next, the movement of the liquid on the free surface is described for the moving free surface boundary condition, which is changed over time. However, this boundary is not used in the CFD simulation calculation but is built using ANSYS Fluent. The transmission formula of the VOF method is replaced. Finally, the ship's first wave height in the simulated situation under different parameters is obtained by simulation. Then the simulation results are used to derive the bow wave height empirical formula related to the number of the Froud number, the draft depth, the blade exit height, and the blade angle. Finally, the high-estimation experience similar to the bow wave fluid analysis is obtained. CFD simulation is also used to propose the mechanism of the isotropic formation of the resistance of the silver nanowire sheet according to the hydrodynamic analysis angle and the different fluid behavior under the blade.
In our simulation, there is a limit on the range of validity, because we directly assume that the blade has reached the final equilibrium position, so the coated film thickness must be greater than the exit height below the scraper, otherwise the blade will not touch the liquid, There will be not generation of the bow wave. Therefore, in the actual situation, the simulation is only applicable when the liquid supplied from the solution supply end is large, and even if the liquid is affected by the blade scraping, the film thickness is still higher than the outlet height. In the simulation, there is also a problem that the mesh size is not refined enough, resulting in inaccurate data, so it can only be used as a reference for its trend.
Although the validity of the simulation results is limited, it can be further referenced by those who continue the simulation in the next stage. The ultimate goal is to combine the bow wave height with the film thickness estimation formula to improve the accuracy of film thickness adjustment.
| Identifer | oai:union.ndltd.org:TW/107CCU00489061 |
| Date | January 2019 |
| Creators | 林劻平 |
| Contributors | 鄭榮偉 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 63 |
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