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This paper provides a user oriented description of techniques for the measurement and analysis of engine cylinder pressures. These techniques were developed for piexoelectric transducers and for digital systems of data acquisition and analysis. Test cell procedures are described for transducer preparation and calibration, and for association of each pressure with its appropriate crank angle. Techniques are also described for evaluating the accuracy of pressure data and for eliminating specific errors. Two examples of uses for pressure data are discussed: the calculation of heat release rate in conventional engines, and the computation of internal flows in divided chamber engines. /GMRL/

The effects of mixture turbulence on combustion in a spark- ignition engine were investigated using a CFR engine. The apparent instantaneous turbulent flame speed during combustion was calculated from a combustion head release model that used measured cylinder pressures and assumed spherical flame propagation. This flame speed was correlated with turbulent intensities measured in the motored engine. The ratio of fully developed turbulent flame speed to laminar flame speed was found to be a linear function of motored turbulent intensity. /GMRL/