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In this work, we investigate the rotor bearing loads of a flywheel-based KERS that are caused by dynamic forces and gyroscopic torques during representative driving maneuvers. Based on the governing equations of motion of a gyroscope, the equations for the rotor-platform interactions are developed. These equations, which relate the vehicle's roll, pitch and yaw rate with the internal transverse torques on the flywheel, are integrated into a commercial vehicle dynamics program. An average passenger car model equipped with a typical high-speed flywheel energy storage system is used for the numerical investigations. The flywheel bearing loads produced by some selected, representative driving maneuvers are simulated for different orientations of the flywheel spin axis relative to the body frame. In addition, the dynamic response of the vehicle to the reaction torques is investigated in open and closed-loop vehicle dynamics simulations.

The objective of this work is an attempt to investigate the longitudinal aerodynamic response of a vehicle to ambient wind. The natural wind environment is usually unsteady and causes therefore slight oscillations of the vehicle's velocity around its cruising speed. The additional force superposed to the steady drag caused by the smooth oncoming air flow is generated by ambient turbulence. For the on-road investigation of the vehicle's longitudinal response to the ambient turbulent flow field both vehicle velocity and relative airspeed in driving direction are recorded by independent data acquisition systems during a set of coastdowns. The deceleration data and the vehicle's response to the airspeed fluctuations are derived by numerical filtering techniques and differentiation of the motorcar's velocity-time history. The study results in a frequency-dependent response function.

In a preceding paper an on-road investigation of the longitudinal aerodynamic response of a vehicle to ambient wind was presented. That study resulted in a frequency-dependent response function with a distinctive maximum within the range of the natural frequency of the vehicle on its suspension system. This finding raised the question as to whether the horizontal response of a car’s deceleration to wind gusts is associated with or caused by the suspension’s natural frequency. The objective of the present work is an attempt to shed some light on this question by the investigation of both deceleration and pitch angle fluctuations in additional on-road experiments. Both vehicle velocity and total airspeed in the driving direction and the pitch angle are recorded by independent data acquisition systems during a set of coastdown experiments.