Engine torque for acceleration of rotational mass in vehicles

This study presents analysis of errors of calculations for engine load during vehicle acceleration phase, resulting from some simplifications or errors in selection of mass moment of inertia. A varied impact of the assumed, on unknown basis, values of the mass moments of inertia on calculation error was shown. According to the author, more accurate results of calculations of coefficient of rotating masses delta can be obtained by means of equations which make use of mass moments of inertia for rotating masses in vehicle Is and I k rather than values of reduction ratios in gearbox, for which the calculated values of delta are inflated. This study presents an overview of methods for calculation of inertia mass in vehicles which impact on inertial resistance. Different opinions in references on rotational mass (engine with clutch mechanism and the road wheels) provided the author an impulse to verify them with respect to currently manufactured vehicles. In particular, profile of reduced mass moment of inertia of rotational masses in vehicle as a function of overall gear ratio, ranges of non-stationary engine working conditions from engine speed, characteristics of demand for engine torque needed for acceleration of rotational masses in the vehicle with acceleration of engine speed are shown in the paper.