Numerical Study on the Effect of Thermocouple Mounting Coating on Temperature Measurement of Nozzle Guide Vane

• Format: Article
• Language: zho
• Published: The Northwestern Polytechnical University 2020-02-01
• Series: Xibei Gongye Daxue Xuebao
• Subjects: nozzle guide vane; thermocouple mounting coating; test error; temperature field; conjugate heat transfer
• Online Access: https://www.jnwpu.org/articles/jnwpu/full_html/2020/01/jnwpu2020381p95/jnwpu2020381p95.html

To analyze the measurement error of thermocouple covered by mounting coating, which is mainly used in air-engine nozzle guide vane temperature test, a mathematical model of the temperature measurement structure was established referring to Mark Ⅱ nozzle guide vane. Based on the heat-flow coupling theory and conjugate heat transfer analysis, the Navier-Stokes equations and heat transfer problem were solved by using SST γ-θ turbulence model. The effects of coating position, coating thickness and coating edge fillet on the temperature of test positions were investigated, respectively. From this study, we find that the temperature predicted by SST γ-θ turbulence model well caters for the test data. The maximum error between calculation and test result is less than 10%. When the leading edge coating is near to the transition point of the suction side, the temperature error will increase. Comparing with that on the middle surface of the pressure side and the leading surface of the suction side, the thermocouple coating has slight effect on the temperature measurement accuracy of the middle surface and the trailing surface of the suction side. If the coating thickness is less than the total temperature boundary layer thickness, the measurement accuracy is almost unaffected. To apply a fillet to the leading edge of thermocouple coating is an effective method to improve the measurement accuracy.