Simulation And Experimental Study Of Cavitation Jet Based On Wheeled Wall-Climbing Robot For Cleaning

With the rapid development of Chinese marine industry,the cleaning of ships is becoming more and more important.At present,traditional way of ship cleaning,especially for removing marine attachment,is still in an artificial way,with low efficiency,environmental pollution and high labor intensity,which has perplexed cleaning industry.It is important to find a new type of alternative cleaning method.In this paper,the combination of cavitation jet and wheeled wall-climbing robot is proposed for the study of ship cleaning.At the same time,the characteristics of the two technologies are reviewed,and the feasibility and significance of combining the two technologies to remove marine attachments are expounded.In this paper,based on the application of wheeled wall climbing robot for ship cleaning,the research of cavitation jet is carried out.First of all,the overall structure of a wheeled robot is designed to achieve stable movement on the wall of the ship,and it has a lighter weight in this paper.The dynamic simulation of the robot is carried out by ADAMS software.The results show that the robot can move steadily under the state of turning and straight,and output the curve of torque and speed,and give the obstacle surmounting performance of the robot.At the same time,the design process is assisted and optimized.The prototype is finished.By analyzing the results of previous studies on cavitation flow,based on the CFD,numerical simulation,cavitation theory,aiming at the actual industrial application and cleaning effect,two kinds of cavitation nozzles,which are the organ pipe cavitation nozzle and the self-resonance pulsed nozzle are designed and manufactured.The internal and external flow fields of the cavitation nozzle are numerically simulated by FLUENT software.Two kinds of nozzles are compared from the simulation point of view.The results show that the gas fraction inside the self-excited oscillation pulsed cavitation nozzle is higher than that inside the organ tube structure cavitation nozzle,and the effect of cavitation is better,and the results are verified with the results of the follow-up test..The experimental platform of the cavitation jet is designed and built,which can produce a stable and controllable cavitation jet and can be observed through a transparent water tank.Cavitation jet is studied by the direct method and indirect method which include erosion test of aluminum block and cleaning of marine attachments.The results show that the effect of the self-excited oscillation pulse cavitation nozzle is better.Meanwhile,the effects of pressure,target distance and nozzle structure parameters on cavitation jet are studied,and the positive correlation between pressure and the erosion force of cavitation jet is obtained,and the best target distance of the cavitation jet is about 20 mm.According to the influence of nozzle structural parameters on cavitation jet,the cavitation nozzle which is most suitable for cleaning is obtained during the test.