Research Of Flow Structure By Video Measurement Technology

In the fields of modern aerospace,weapons and energy,quantitatively measurement is necessary for temperature and density of complex gas flow field,such as gas flow field around missile,density of rocket gas and temperature field in wind tunnel,etc.Traditional contact method urgently needs to solve the following problems: firstly,test model exists large vibration under the function of flow at the quantitatively measurement of fluid in high-speed wind tunnel,which makes a difference to the quantitatively measurement;On the other hand,it is hardly to achieve dynamic instantaneous and stereo measurement for the temperature and density change with time.Therefore,the video measurement technology of fluid structure are researched in this paper.A movement decoupling method of flow and test model which based on Background texture disperse matching is proposed according to the obviously texture on test model.It disperses image and compute map matrix of each sub-image in time series,it also achieves precise registration of sub-image by deriving the smooth map calculation according to the movement continuity of adjacent discrete sub-image.The Oseen vortex simulation experiment of simulating oil film motion proved the method in this paper is feasible and the fluid flow structure measured is correctly,the error between results of this method and Theoretical value is 4.1% in vibration condition,it has only 0.6% increment compared with that of no vibration condition.In addition,this paper solved a large number of wind tunnel experiments such as the cavity flow structure measurement,the wing surface flow structure measurement and the aircraft model surface flow structure measurement,and analysis its flow topology structure combined with the flow mechanism have proved that this algorithm is validity and correctness under complex conditions.In order to realize the real-time measurement of the flow structure of space fluid,an Algebraic Reconstruction Technique(ART)3D reconstruction method based on optical tomography is established to realize the three-dimensional reconstruction of fluid density field based on optical deflection.The simulation experiment show that the proposed method is feasible and the result is correct.The three-dimensional reconstruction experiment of airflow structure proves that the airflow 3D reconstruction optimization algorithm can realize a small amount of projection direction reconstruction,and its reconstruction effect is credible.