Computing The Optimum Knock Sensor Locations

This paper describes a computational technique and a procedure to select the optimum knock sensor locations in order to augment the currently employed measurement techniques.

The technique is Finite Elements based and uses the Frequency Domain Forced Response Analysis to estimate the vibration propagation on an engine block. The results are post processed to obtain the RMS value of normal surface vibrations. The optimum location for the knock sensor is then obtained from the RMS value contributions of potential knock pressures from each cylinder.

The predictive ability of the method has been tested against actual measurement data during several development programs where a good agreement with the sensor locations determined by measurements and the computational method was obtained.

The method can be instrumental in indicating optimal measurement locations and potentially reduce the amount of data collected.