Experimental investigation of diluted gas behavior flowing through microchannels

• Main Authors: Ding Zhao-Bo, 丁肇柏
• Other Authors: Yu-Hsuan Su
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/mmfu8v

碩士 === 國立臺灣科技大學 === 機械工程系 === 106 === The micro-channel system was fabricated using MEMS technology and Knudsen was made due to the reduction in feature size The number increases, when the gas gradually enters the slip flow regime by the continuue regime, the traditional slipless The shifting conditions and theory will no longer apply to this. When the gas enters a thin condition, the microscopic gas fraction must be considered. Exchange of momentum between the sub-molecule and between the gas molecules and the solid boundary, and the gas molecules and solids The momentum exchange between the boundaries is defined as the tangent momentum correction factor (TMAC), which is the main Explore one of the important parameters affecting mass flow rate. In the experiment, the measurement method is a double-slot cumulative measurement system, which is compared with the traditional single-slot accumulation. The biggest difference in the measurement system is that the amount of mass flow rate change caused by temperature can be reduced, and the exact amount The amount of change in the mass flow rate created by the flow of the test gas into the cylinder was measured. In the experimental parameter setting, the main control of upstream and downstream pressure and then change the gas Newson number, in this paper The gas motion behavior will be divided into slip flow and transition flow using Newson numbers for analysis. The results of this experiment show that when the gas is in slip flow, the parameters that mainly affect the mass flow rate are made upstream and downstream. The pressure difference is changed, and another important conclusion is that even if the experimental gas is different in the same flow channel, The TAMC obtained in the experiment does not change too much with the difference of the gas, so the result of this experiment TMAC can be considered as a fixed value, in other words, there is only one TMAC value in one flow channel, and TAMC Is a constant. When the gas is in transition flow, all the previously derived formulas will no longer apply to this, so in the experimental setup The pressure difference between the upstream and the downstream will be fixed, mainly to observe the relationship between the gas density and the mass flow rate. It is shown that the parameters that mainly affect the mass flow rate in this section are the molecules passing through the outlet section per unit time. Number, but when the gas gradually enters the free molecular by the transition flow, due to the gas molecules in the microchannel The chance of collision with other gas molecules in the middle flow is extremely small, which leads to the mass flow rate gradually increasing with the Newson number. turn off.