ANALYSIS AND COMPARISON OF CLEAN VS INLET DISTORTION FLOW PHYSICS AT DESIGN OPERATING CONDITION USING PROPER ORTHOGONAL DECOMPOSITION

摘要

Assessing the impact of inlet flow distortion in turbomachin-ery is critical to the safe and efficient operation of many engineered systems. This paper introduces and validates the use of methods based on the Proper Orthogonal Decomposition (POD) to analyze clean and 1/rev static pressure distortion simulation results at design operating condition. The value of POD comes in its ability to efficiently extract both quantitative and qualitative information about dominant spatial flow structures as well as information about temporal fluctuations in flow properties. The analysis was used to quantify circumferential varying stage performance in terms of shock location and strength. Since the result of 1/rev total pressure distortion is circumferential varying stage performance, POD is a useful means to analyze and quantify such variation. Observation of the modes allowed qualitative identification of Shockwaves as well as quantification of their location and range of motion. Modal coefficients revealed the location of the passage shock at a given angular location. Distortion amplification and attenuation between rotors was also identified.