Analysis Of Nozzle External Flow Field And Design Of Automatic Spray Systerm With Experiment Research

Circle type precise carbon film potentiometers are widely used as angulardisplacement transducers in the hydraulic servo systems in areas of aeronauticsand astronautics. As a key component of circular potentiometers, the quality ofresistor film (carbon film) is crucial to the performance of servomechanismsHowever, there exists some problems in the traditional manual spray method,such as the instability of process parameters, and poor quality of carbon film,poor efficiency of production which increase the production cycle, seriouslyaffecting the delivery of products. Therefore, studies on the film spray techniqueis of importance to improve the technique level of China’s circular potentiometer.Firstly, use CFD software to simulate the nozzle external flow field anddiscussed the effects of spray gun operating parameters on liquid atomization,and then select appropriate nozzle and operating parameters, which laynecessary theoretical basis for the rational design of spray system In addition,the method of automatic spray film was proposed.Secondly, based on the method of automatic spray, a potentiometerautomatic spray system was established. The system consists of hardware andsoftware. The hardware part consists of purchased parts and self-designed fixtureand special purpose circuits. The software is written with LabVIEW2009,combining functional modules such as axis movements、digital I/O, actions ofspray gun together, the control software has friendly interface and was easy-operating The system provides stable and reliable experimental platform forexperimental study of film spray process.Thirdly, with assurance of the system stability，several experiments areconducted. The result of experiment proved the correctness of film stackingmethod. And then determine the important parameters of the film spray, such asthe times of film spray, time delay of film spray, speed of base body. At the sametime, it also proves that selecting the spray gun operating parameters by the CFDsimulation is appropriate, the sprayed product with better linearity. The resultscould meet the requirements of practical production.Finally, in-depth study of the two-phase flow theory and orthogonal experimental design need to be discussed in the future study.