This paper presents a novel model for flow angles at off-design conditions.The model is based on energy conservation in turbomachinery.By the mean of average process,statistical properties of the wake profile are rela...This paper presents a novel model for flow angles at off-design conditions.The model is based on energy conservation in turbomachinery.By the mean of average process,statistical properties of the wake profile are related to the flow angle and mainstream parameters;then by adopting the classic flow topology of behind-blade wakes,the effect of operating conditions is included in the plot and a model for flow angle is thus developed.The advantage of the model is that it can achieve off-design flow angle estimations with design flow characteristics and it is compatible with CFD-based throughflow methods.This model is then implemented into a standard CFD-based throughflow solver from the previous research to estimate off-design characteristics of blade rows with proper input-output strategies.Furthermore,the effect of loss upon flow angle is also modeled as corrections to the proposed model.The model is validated on a compressor stage and the results show promising accuracy for off-design flow angle estimations.展开更多
This paper presents a novel approach of modeling the air-cooled turbine with CFD-based throughflow analysis. Starting from the basic equations of motion, governing equations and source terms for mass, momentum and ene...This paper presents a novel approach of modeling the air-cooled turbine with CFD-based throughflow analysis. Starting from the basic equations of motion, governing equations and source terms for mass, momentum and energy are formulated in an analytical manner. These source terms are to mimic the authentic injection-mainstream interactions with easy implementation. The source terms in the aero-cooling scenario are related to corresponding sources in the aerodynamic-only analysis. Based on such formulations, a novel strategy is developed to estimate aerodynamic characteristics of a blade row under film cooling with known characteristics under no cooling. The model and the strategy are validated in the classic NASA E3 turbine guide vane under various operating conditions. Sensitivity studies of input parameters are conducted to evaluate the applicability of the proposed model. Specifically, the flow rate distributions of cooling flow at different cooling holes are crucial for accurate predictions.展开更多
基金funded through the National Science and Technology Major Project(2017-Ⅲ-0009-0035)National Natural Science Foundation of China(Grant No.52276031)。
文摘This paper presents a novel model for flow angles at off-design conditions.The model is based on energy conservation in turbomachinery.By the mean of average process,statistical properties of the wake profile are related to the flow angle and mainstream parameters;then by adopting the classic flow topology of behind-blade wakes,the effect of operating conditions is included in the plot and a model for flow angle is thus developed.The advantage of the model is that it can achieve off-design flow angle estimations with design flow characteristics and it is compatible with CFD-based throughflow methods.This model is then implemented into a standard CFD-based throughflow solver from the previous research to estimate off-design characteristics of blade rows with proper input-output strategies.Furthermore,the effect of loss upon flow angle is also modeled as corrections to the proposed model.The model is validated on a compressor stage and the results show promising accuracy for off-design flow angle estimations.
基金funded by the National Natural Science Foundation of China (Project 51876098)the National Natural Science Foundation of China (Project 51911540475)the National Science and Technology Major Project (2017-Ⅲ-0009-0035)。
文摘This paper presents a novel approach of modeling the air-cooled turbine with CFD-based throughflow analysis. Starting from the basic equations of motion, governing equations and source terms for mass, momentum and energy are formulated in an analytical manner. These source terms are to mimic the authentic injection-mainstream interactions with easy implementation. The source terms in the aero-cooling scenario are related to corresponding sources in the aerodynamic-only analysis. Based on such formulations, a novel strategy is developed to estimate aerodynamic characteristics of a blade row under film cooling with known characteristics under no cooling. The model and the strategy are validated in the classic NASA E3 turbine guide vane under various operating conditions. Sensitivity studies of input parameters are conducted to evaluate the applicability of the proposed model. Specifically, the flow rate distributions of cooling flow at different cooling holes are crucial for accurate predictions.