Optimize The Pneumatic Measurement Instrument Parameters

The system of pneumatic measurement is widely used to check the part size, for advantages of high measurement precision, little power of measurement, auto-sweep part surface, good keeping measurement accuracy, strong anti-interference ability and so on. But for the micro-diameter of nozzle, and complex air flowing situation based on which, it is hard to choose fit diameter for the nozzles. It has great significance to optimize the parameters of diameters of main nozzle and measurement nozzle, which determine the range and sensitivity of the system. A common method is to make a lot of nozzles with different diameters and choose by experiment.In this work, a 3D model is built on the base of research on the theories of pneumatic measurement and aerodynamicist, and was simulated by the CFD software of FLUENT. How the air flowing in the equipment when work is shown from the visualization result and the possibility of the pneumatic measurement is well proved. Then different parameters of distance between the flapper and measurement nozzle is introduced in the model and simulated. Regulation is found from the final simulation result and based on which, the parameters are optimized when design.Experiment equipment and method are designed and built as need and different diameters of main nozzle and measurement nozzle are produced for experiment. Accuracy of the simulation result is proved to be right from the experiment result. Optimization of main nozzle diameter and measurement nozzle diameter parameters is proved well improved the effect of pneumatic measurement equipment, especially the flapper-nozzle. This method improved the efficiency when designing the parameters of pneumatic measurement and the simulation result of air flowing situation has great significance to the later work on designing the pneumatic measurement equipment.