| Summary: | 碩士 === 國立交通大學 === 機械工程系所 === 105 === This research aims to characterize the stress distribution of the microstructures during spray cleaning process, since the water spray may impact the microstructures and result in the structural damage. In order to improve the yielding rate, it is required to understand the stress distribution during the cleaning process. Finite element analysis was performed to simulate the behavior of the microstructure. Moreover, several parameters associated with the cleaning process and the geometric dimensions of microstructure were discussed.
Based on the Fluid-Structure Interaction (FSI) analysis, the spray cleaning model for the microstructures was established initially, from which the stress analysis of the microstructures during spray cleaning process was calculated. Simulation results from the two-dimensional model of single microstructure indicated that the states of stress in the structures with high aspect ratio are high. In addition, from the analysis of the three-dimensional pattern containing three microstructures subjected to three different directional flows, it was shown that the microstructures have high stress when the flow direction is perpendicular to the length of microstructures. Furthermore, when the space of the microstructures is less than 200nm, the stress in the microstructure is relatively low. Subsequently, the damage zone size of microstructures with inner diameter 2.86mm and outer diameter 6.64mm affected by flow field were evaluated which is close to the experimental observation. In addition, when the space of the microstructures increase, the structures are prone to be damaged. Simulation results also show that when either spacing is larger than 100nm or surfactant is included in the water, the extent of air trapped in the microstructure can be reduced.
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