燃气轮机涡轮排气扩压器气动性能的不确定性量化和敏感性分析

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中图分类号：TK474.7 文献标志码：A

Abstract： Deviations in the geometric parameters and operational fluctuations of gas turbine exhaust diffusers can lead to significant uncertainties in aerodynamic performance， thereby affecting the overall performance of the unit. This paper establishes a system for quantifying uncertainty and analyzing sensitivity in the aerodynamic performance of diffusers， utilizing Latin hypercube sampling， non-intrusive polynomial chaos expansion， and Sobol’ indices sensitivity analysis method. The study quantifies the efects of divergence angle，inlet swirl angle，and inlet velocity on the static pressure recovery coefficient， total pressure loss coefficient，and dynamic pressure conversion coefficient. The results indicate that when considering uncertainties in inlet velocity，inlet swirl angle，and divergence angle， the statistical distribution of aerodynamic performance parameters follows a normal distribution. The flow field near the strut is most sensitive to parameter perturbations， with the maximum deviation in the static pressure recovery coefficient reaching 50.1% . The mean value of the static pressure recovery coefficient increases by 2.654% compared to the design value，and the probability of deviating by 10% from the design value is 11.04% . The mean value of the total pressure loss coefficient increases by only 0.111% ，but the probability of deviation is as high as 25.22% . The mean value of the dynamic pressure conversion coeficient increases by 2.023% ，with a probability of deviation of 0.63% ： Sobol' indices sensitivity analysis results show that the inlet swirl angle is the dominant variable for uncertainties in the static pressure recovery coefficient and total pressure loss coefficient， contributing 72.84% and 98.34% ，respectively. The divergence angle is the dominant variable for uncertainties in the dynamic pressure conversion coefficient，accounting for 65.43% of the variance. Compared to the main effect， the contributions of inlet velocity and second-order interaction effects are negligible.

Keywords： gas turbine; exhaust diffuser; aerodynamic performance; uncertainty quantification; sensitivity analysis

在现代能源动力工程领域，燃气轮机凭借其高效的能量转换能力和广泛的应用场景，成为推动工业发展与能源利用的关键设备，其中排气扩压器作为燃气轮机排气系统的核心部件，在整个动力循环中发挥着不可或缺的作用。（剩余16948字）