An Off-Design Flow Angle Model Based on Average-Flow Theory and Wake Analysis.

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. [ABSTRACT FROM AUTHOR]