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This paper reports the development of a method for evaluating the intensity of turbulent velocities by using a cross-correlation technique for pattern tracking. With this method, only a pair of flow field images having a short time interval between them is required to perform the evaluation. The method is verified partially by its ability, when it is simplified, to reveal several phenomena observed previously in the velocity measurement by the cross-correlation technique for pattern tracking. An application to the estimation of turbulent intensity in a diesel engine combustion chamber after combustion is described.

High speed photographs of spray and combustion, obtained from a Hydra direct injection research diesel engine are compared with the predictions made by KIVA-3 computer code. The preprocessor has been modified to generate a grid for an offset bowl and the postprocessor has been extensively reprogrammed to obtain contour maps. The model has been tuned to low load at 2000rpm. Then the predictive capability of the model has been verified at other operating conditions. Predicted results show very good agreement with the experimental data.