Invariant Sets and Explicit Solutions to a Third-Order Model for the Shearless Stratified Turbulent Flow

We study dynamics of the shearless stratified turbulent flows. Using the method of differential constraints we find a class of explicit solutions to the problem under consideration and establish that the differential constraint obtained coincides with the well-known Zeman--Lumley model for stratified flows.Comment: arxiv version is already officia

Modelling and Simulating the Efficiency and Elasticity of Gearboxes

Two elastic gearbox models with friction losses are presented; a 1-Degree Of Freedom (DOF) and a 3- DOF model. The presented models have advantages over the existing lossy gear model [7] of the Modelica Standard Library when gear vibrations are of interest. Care has been taken that also in the case of gear locking, the elasticity effects are treated adequately. In addition to external excitations, it is now also possible to model internal excitations of the gearbox caused by the varying stiffness and/ or damping. This varying stiffness can be specified by the user for each gear wheel. This feature can for instance be used to model tooth interaction or broken gears. Furthermore, the 3-DOF elastic model can simulate the elasticity of the support bearings in the load direction, which is impossible in the standard lossy gear model