Nikolaos Katopodes's research while affiliated with University of Michigan and other places

Publications (9)

Conference Paper
A new generation of a planetary-gear-based automatic transmission system is designed with an increasing number of ratio steps. It requires synchronous operation of one or more wet clutches, to achieve a complex shift event. A missed synchronization results in drive torque disturbance which may be perceived by vehicle occupants as an undesirable shi...
Article
Wet clutch packs are the key component for gear shifting in the step-ratio automatic transmission system. The clutch plates are coupled or de-coupled to alter gear ratios based on the driver’s actions and vehicle operating conditions. The frictional interfaces between clutch plates are lubricated with automatic transmission fluid (ATF) for both the...
Article
Wet clutch packs are the key component for gear shifting in the step-ratio automatic transmission system. The clutch plates are coupled or de-coupled to alter gear ratios based on the driver’s actions and vehicle operating conditions. The frictional interfaces between clutch plates are lubricated with automatic transmission fluid (ATF) for both the...
Article
Wet clutch packs are widely used in today’s automatic transmission systems for gear-ratio shifting. The frictional interfaces between the clutch plates are continuously lubricated with transmission fluid for both thermal and friction management. The open clutch packs shear transmission fluid across the rotating plates, contributing to measurable en...

Citations

... Apart from the static behavior, the model describes the main dynamic effects such as inertia, shuffle mode, and tire damping effects. For more detailed analyses of powertrain response robustness and final CAD effort in refining/calibrating the control strategy, the powertrain model can be upgraded to cover broader dynamics effects such as drivetrain NVH, wet clutch dynamics and similar (Fujii, Tobler, Pietron, Cao, & Wang, 2003;Haria et al., 2018). ...
... Cui et al. [22,23] studied the axial hydrodynamic force and drag torque of friction pairs with a conical deformation disc. Wang et al. [24] proposed a statistical method to describe the distribution of disengaged friction pair gaps, finding that the more uneven the gap distribution is, the larger the drag torque is. Despite the clutch disengaging process is crucial to the shifting performance of a transmission system [25], no systematic study concerning its disengaging dynamic characteristics has been published yet. ...
... Conversion of motion coordinate system is required given the functional limitations of computational software. In the simulation, a relative coordinate system is established using the tank body as a reference, the tank advancement is achieved with a multiple reference frame (MRF) model, and the track rolling is simulated by setting moving walls [27,28]. In Fig. 5, the conversion of the motion coordinate system is illustrated, where the tank travel speed is V1, the front wind speed is V2, and the x direction is considered the positive direction. ...