Finding the Real Surge Boundaries of Turbo-charged Automobiles Using Intelligent Fuzzy Reasoning Technique

Abstract

Engine with turbo charger needs to be aware of the potential damage caused by surge phenomena. The focus of this paper is to propose a new intelligent reasoning to find the real surge boundary for a turbo-charged automobile without performing real complicated automobile experiment. Four physical fuzzy variables of a turbo-charged automobile, i.e., throttle size, pressure ratio, engine displacement, and total effective pipe length between the throttle and turbo charger, are chosen as the input to our intelligent reasoning algorithm system to produce the mass air flow for correction. The mass air flow for correction can then be applied on the compressor map of turbo charger to determine the real surge boundary for a certain turbo-charged automobile. In comparison with the previous approach using quadratic interpolation formula for exact real surge boundary, our new approach can indeed produce nearly the same answer with simplified computation load. Excellent benchmark tests are conducted on Saab NG 900 and 9000 with turbo chargers, Garrett T25-60.