| The overall calibration of hypersonic wind tunnel flow field has become the vital problem being solved in the construction of hypersonic wind tunnel and the development of related test techniques.The measurement of total pressure distribution is an important data source for flow field calibration.The existing flow field pressure measurement technology can not satisfy the test requirements due to the small number of measurement points,long measurement time and low efficiency.Therefore,it is necessary to study the measurement technology and its implementation device which can reflect the total pressure distribution on the cross-section of the nozzle exit as much as possible.In order to measure the total pressure distribution of hypersonic wind tunnel accurately and solve the problem of insufficient stiffness of the measuring device in use,the model of the total pressure measuring device used in a hypersonic wind tunnel is established according to the technical requirements of total pressure measurement,and the static and dynamic characteristics of the model are analyzed.Structure optimization of the total pressure measuring device is performed based on it's static and dynamic characteristics.The effect of the structural parameters of the total pressure tube and the distribution of the measuring points on the static and dynamic characteristics of the total pressure measuring device is studied.The optimal structure parameters and layout of the total pressure tube are obtained,and the experimental verification and analysis of the total pressure measuring device in hypersonic wind tunnel are carried out.The main contributes are as follows:According to the technical requirements of total pressure measurement,the model of total pressure measurement device is established,and the static and dynamic characteristics of total pressure measurement device are analyzed.The static and modal analysis results illustrate that the structural strength and vibration performance of total pressure measuring device satisfy the technical requirements,but the stiffness does not meet the requirements,and total pressure tube is the key part affecting the stiffness of total pressure measuring device.The effect of structural parameters of total pressure tube on the static and dynamic characteristics of total pressure measuring device is explored by using the orthogonal experimental design method and the single factor experimental method.The optimal combination of structural parameters of total pressure tube is obtained,and the structural optimization of total pressure measuring device is realized.Taking the main structural parameters of total pressure tube as experimental factors,the orthogonal tests of numerical simulation are carried out with the static and dynamic characteristics indexes of total pressure measuring device taken as test indexes.The results indicate that the optimum combination of structural parameters are as follows: the length diameter ratio is 24,the outer diameter is 6mm,the diameter ratio is 0.4 and the probe deflection angle is 30°,respectively.The effect of distribution distance and distribution form of total pressure tube on the static and dynamic characteristics of total pressure measuring device is studied by means of comparative analysis,and the better distribution of measuring points is obtained.The results demonstrate that the structure of the “meter” shape model is better than that of the “water” shape model,and the distribution of the “meter” shape measuring points with the spacing of 15 mm is the better layout.The total pressure measurement experiment of hypersonic wind tunnel flow field is carried out by using the “meter” shape total pressure measuring device with the distance between measuring points of 15 mm.The experimental results illustrate that the total pressure data measured by the total pressure measuring device in this paper has good uniformity and high accuracy,which can be applied to the total pressure measurement of hypersonic wind tunnel flow field. |
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