Development Of A Helicopter Tank Shaking And Cleaning Test Platform

The aircraft fuel tank is a device which provide fuel to the aircraft.One of the flight safety guarantee measures is to ensure the cleanliness of the oil inside the aircraft fuel tank.Whether the fuel tank is newly manufactured,or used for a period of time,or maintenance and other cases,it needs to be cleaned inside.However,due to the complex internal structure of the fuel tank,all kinds of cleaning tools cannot enter the inner cavity,so some of the fuel tank cleaning still adopts the manual cross-shaking vibration method,which often results in incomplete oil or slag cleaning and requires repeated cleaning,resulting in high manual labor intensity and low efficiency.Based on the cooperation with a state-owned machine factory,I carried out the theoretical analysis of fuel tank cleaning ways and methods,and developed a fully automatic fuel tank cleaning equipment into use.The experimental results show that the equipment has good cleaning effect,improved cleaning efficiency and reduced labor cost.The main research contents are as follows.First,the mechanism theory of fuel tank cleaning in the laboratory bench was analyzed.The fuel tank was analyzed under different working conditions by using computational fluid dynamics software,and the flushing force and liquid surface shaking effect of the internal cleaning fluid on the tank wall under different working conditions(rotation mode,liquid filling ratio and rotational speed)were compared and analyzed by using the control variable method.The analysis results show that when the fuel tank rotates around the Z and X axes,the washing force of the cleaning fluid in the tank on its wall is greater than rotating around the Y axis,and the liquid surface shaking amplitude at 0.3 filling ratio is larger than that of0.5 and 0.7 filling ratio.Both mentioned results before provide the basis for the design of the following laboratory bench.Second,the structural design and strength check of the cleaning mechanism of the laboratory bench.A three-dimensional model of the mechanical structure of the laboratory bench was constructed in Solidworks software,including the motion mechanism and the mounting fixture that can be applied to multiple tank sizes,and the execution motor model was determined by calculation.Workbench was used to analyze the key components of the test bench and optimize the structure where the strength of the test bench was insufficient.The final results show that the structural strength of the laboratory bench meets the requirements of use.Subsequently,a control system was designed to automate the laboratory beench.The PLC is used as the controller and the inverter is used to realize the speed control of the actuating motor of the experimental table mechanism,and the touch screen is used as the host computer to realize the user-defined parameter input.The system includes self-test,media injection,cleaning(shaking vibration),and media removal functions.PLC realizes the reception and output of external signals by compiling ladder diagram programs,and also designs a friendly human-computer interaction interface for the host computer.Finally,the laboratory bench was installed and debugged.The fuel tank was installed and fixed with a fixture,the medium was injected,and then the cleaning function test run was carried out.The experimental results show that all the functions of the laboratory bench can meet the requirements and the cleaning effect is satisfactory.