| The flow measurement is closely related to industrial productionand native lives, and it is always an important topic concerned by researchers.Accompanied the tendency of miniaturization in science technology andindustrial engineering, macroscopic flow measurement problem has beentransferred to the field of micro. The accurate measurement of fluid flow inmicro-scale became a new hot research field, in which the design andapplication of the micro flow sensors are desperately needed. In order tosolve the above problems mentioned and adapt to this trend, the new fluidicoscillator without feedback channel is proposed as the flowrate sensor inmicroscale tubes and studied in aspects of the theoretical analysis, modelstructure design, numerical simulation and experiment researchsystematically. Based on the law that the oscillation frequency of fluidicoscillator and velocity are linear relationship on the specific fluid tubes, theflow measurement methods are presented for microfluidic flow sensor, andthe2D and3D simulation and experimental research methods are employedto study the flow sensor technology in microscale.In the end, the parametersof dynamic characteristics of flowrate sensor are obtained and the flowmeasurement model of microfluidic are established.(1)The theories and research methods related to the micro flow measurement inMEMS are generalized. The unique advantages and the research status of fluidicflowmeter in flow measurement are introduced in detail. The microfluidics researchand the computational fluid dynamics method are summarized.(2)The working principle of flow measurement of fluidic sensor is described,included the concept, classification, characteristics and application of fluidic media,the principle of entrainment effect, wall attachment and bistable fluidic element. Theprinciple and mathematical model of flow measurement based on fluidic oscillationare studied in detail. (3)A new fluidic oscillator without feedback channel is proposed as theflowrate sensor in microscale tubes, and the2D and3D geometric models andgrid computing models of the sensor are established. A computational fluiddynamics (CFD) method is employed by2D and3D numerical simulation tostudy the measurement characteristics of the flow sensor, and the dynamicoutput characteristics fluid oscillator and the flow measurement model ofmicrofluidic are obtained.(4)In view of the simulation results, two kind depth microfluidic chip aredesigned and processed. The fluid display technology, Micro-PIV isemployed to research H60and H100of fluidic oscillator, and the the resultsof the experiment are analyzed systematically. |
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