The Research Of Turbine Blade Heat Distribution Measurement Method

Gas turbine, as the most advanced type of thermodynamic device is widely used in variousfields such as aerospace, aviation, ships, electricity and so on.Turbine blade is one of thehighest parts of the work load, at the same time is also one of the highest parts of the failurerate in the gas turbine, therefore, in the study of gas turbine technology is both key points anddifficult points as well. Temperature is a significant parameter to determine the state of matter,which is also an important process parameter in industrial production. For turbine blades,since the temperature can reflects the operating state of the blade directly, through theresearch about the temperature distribution on the blade surface, the processing technology,the service life, the cooling performance, etc. of the blade can be analyzed. When gas turbineis working, the turbine blade spin at a high speed, the surface temperature distribution isgreatly impacted of the thermal stress, the gas force, etc., substantially unable to determine thesize of the error caused by these factors on the temperature measurement result in a dynamicmeasurement.This topic by reading a large amount of literature about gas turbine heat transfer andcooling technology, builds a turbine blade temperature measurement platform in thelaboratory environment, and makes some experiments able to be carried out in the laboratorywhich do not really need in a specific environment. The temperature measurement platformchooses the electric furnace to produce the heating environment for turbine blades, and usesthe optical scanning and radiation thermometry method to measure the blade surfacetemperature distribution. Through studying several common scanning modes, combined withthe existing conditions in the laboratory, the45°rotating mirror scanning method wasadopted to complete temperature data acquisition on the blade surface. Based on thisexperiment platform, the following experiments have been finished, for example, thecorrelations between the temperature distribution on the blade surface and the internal airwaystructure, establishment of a mathematical model of the blade surface temperature distribution,the influence of measuring angle and blade surface reflectivity on the temperaturemeasurement results and so on.The analysis of experimental results proves that this system can effectively measure thetemperature distribution on the turbine blade surface, and build the respective corresponding relations between the blade temperature distribution and the internal airway structure. At thesame time, on the basis of the experimental data, with the help of a nonlinear least squaresfitting method the mathematical model of the temperature distribution on the blade dorsalsurface is developed, and the mathematical relation of the temperature after air cooled totemperature field and the blade position is given.