DEFINITION OF TURBULENCE IN IN-CYLINDER FLOW-FIELDS

The definition of turbulence of in-cylinder flow fields has been an im portant issue for researchers working on in-cylinder gas motion. This study proposes a definition of the ''turbulence component'' in both th e calculation and measurement. Also, a new method to make a precise co mparison between the calculation and measurement is presented theoreti cally. This method implies changing the coefficient, C(D), which is in cluded in expressions for turbulence energy, its dissipation rate and turbulence length scale. Employing this method demonstrates the possib ility of reducing the ambiguity of the cut-off frequency method to det ermine turbulence experimentally and also of improving the reliability of the calculation code.