Characterizing and Detecting Surge and Co-Surge in Automotive Compressors

Abstract The instability phenomena associated with compressor surge impose limitations on the operation of turbocharged engines because of undesired noise, engine torque capability constraints, and hardware strain. Characterizing and detecting surge is of interest, e.g., when defining the useful operating range for a compressor or for advanced online mitigation techniques. To that end, an intensity metric based on classical wave theory is proposed. The metric is computed based on measurements capturing the surge oscillations in either pressure or mass flow. The metric characterizes how powerful the surge oscillations are and is effectively a scaling of the oscillation amplitude with the thermodynamic conditions. An algorithm for computing the intensity and detecting surge is developed and demonstrated on a single-turbo I-engine and a twin-turbo V-engine application exhibiting deep surge and co-surge, respectively. The advantages of the metric are highlighted and differences in using pressure versus mass flow sensors for computing the oscillation amplitudes are discussed.