Fluorescence Oil Film Global Thickness Measurement And Friction Resistance Measurement Error Analysis

In the fields of aerospace and aerodynamics,the measurement of frictional resistance has always been the focus of research.Under the action of frictional resistance,fluid motion can characterize the state change of the boundary layer.Frictional resistance is not only an important physical quantity to describe the turbulent boundary layer,but also has a very important reference value for the design of the shell of the aircraft.This thesis firstly surveys the friction resistance measurement methods in recent years.Compared with many methods,the fluorescent oil film global measurement technology is selected,and based on this technology,the global thickness measurement of fluorescent oil film and the error analysis of friction resistance measurement is carried out.Firstly,starting with the theoretical knowledge of fluorescent oil film global measurement technology,the global measurement model of fluorescent oil film measurement technology is deduced,and the relationship between fluorescent oil film thickness,moving speed and friction resistance and the error in the experimental process are analyzed.Then,the theoretical knowledge related to GPU is studied,and the optical flow algorithm is used to calculate the motion speed of the fluorescent oil film in combination with the hardware structure,and the streamline diagram of the motion path of the fluorescent oil film is drawn.Maximize the use of threads and avoid bank conflicts.Aiming at the problems of huge amount of image data collected by fluorescent oil film and low calculation efficiency,an optical flow parallel accelerated real-time calculation method is proposed based on shared memory.The image block processing model is designed to achieve the effect of fast memory access,and the critical constraints corresponding to the optical flow method are created to improve the solution efficiency of the optical flow algorithm.The simulation experiment verification and the experimental verification of two experimental wing models and aircraft models in the wind tunnel have been completed.The experimental results show that the speed of this method is 10.09 times higher than that of the traditional method,and the solution rate can reach 90 frames per second.The relationship between the intensity of the fluorescent oil film and the thickness of the fluorescent oil film was studied,the advantages and disadvantages of the traditional data interpolation method and the neural network method were compared,and a complete set of fluorescent oil film thickness measurement scheme was designed.The experimental scheme has been verified by wind tunnel experiments.certain feasibility.Finally,with the hardware support of GPU,a software system for global measurement of fluorescent oil film is designed and built.The system realizes the functions of batch experimental data processing and observation of the flow state of fluorescent oil film during the experiment,saving a lot of money for researchers.data integration time.The wind tunnel experiment was completed to verify the feasibility and effectiveness of the software.The errors caused by the vibration of the experimental model and the change of the distance of the ultraviolet light source during the wind tunnel experiment of the fluorescent oil film global measurement technology are analyzed.