Harmonic Analysis Speeds Solutions for Challenging Transient Blade Row Problems
Accurate and efficient prediction of blade transient phenomena are becoming more and more important to turbomachinery designers because the continuing need to gain performance improvements makes it necessary to operate closer to performance envelopes. Traditional full-wheel transient solutions provide high levels of accuracy but are computationally expensive because they require simulating many or all blade passages in a given blade-row. Pitch-change methods reduce the problem to a small sector of the geometry but still require the simulation of many vibration cycles to reach a quasi-steady periodic state. The HA method in ANSYS 19.0 helps overcome this challenge by solving multistage transient blade row problems by calculating as few as one blade per row, reducing computational time by a factor of 100 compared to a full wheel solution and by a factor of 25 compared to the FT method, the previous state-of-the-art for this type of problem.