Novel CFD approach for the thermal analysis of a continuous variable transmission (CVT)

The scope of this work is the development of a numerical model which is capable of predicting thermal conditions concerning a continuous variable transmission (CVT). State of the art literature covers the mechanism and power losses of CVT-systems in detail, though a thermal investigation is not available so far. Computational fluid dynamics (CFD) is used for this task. Transient simulations are not feasible because of high computational costs. Hence, the case needs to be simplified to a steady-state problem. Motion has been modeled by using the multiple reference frame (MRF) approach but the prediction of the pulley surface temperature is misleading. Local heat input, e.g. from the belt and asymmetric flow conditions are primarily responsible for the inaccuracy. The novelty of this study is the thermal modeling of heated pulleys where the errors, resulting from a steady state simulation, are compensated. The stability of the solution and the time efficiency are further advantages of the presented approach. Subsequent studies to optimize the CVT are the next step to increase fuel economy and reduced emissions.