Theoretical Description and Numerical Simulation of the Hydrodynamic Coupling

Abstract

The article’s subject is to study and describe the processes in the hydrodynamic coupling during its operation. The hydrodynamic coupling is a type of hydrodynamic transmission that provides a flexible connection between the input and output shafts, in contrast to the mechanical coupling. Currently, the fluid couplings are widely used and the theoretical description of their operation has been given long before. However, in Russia these units are not produced, the theoretical model is very simple while the experimental data are scattered and non-systematized. So the problem is relevant and requires consideration. The research objective is to complement the existing theoretical model for better describing the fluid coupling operation as well as to compare the results, based on its using, with the numerical simulation results. The main part of the article contains these sections. The mathematical model shows: the equations used for theoretical description of the fluid coupling operation, the basic hydrodynamic equations converted to solve the problem in a stationary setting, and the applied turbulence model (k-ω). The author backslides from the standard jet theory in which the calculation is performed at an average trickle in order to take into consideration the non-uniformity of the velocity distribution in the fluid coupling. The article also raised the issue on the applicability of the stationary formulation of the problem for the numerical simulation. The study revealed that the solutions obtained under stationary and non-stationary calculations practically match. The verification was conducted by three points of characteristic of the hydraulic coupling. The article gives the fluid coupling dimensions, represents an image of its threedimensional model and of the computational grid. It also shows some figures to illustrate the processes in a fluid coupling obtained by its numerical modeling. During the study it was found out that the proposed theoretical model allows us to have higher precision and higher quality in representation of fluid coupling characteristics; the article shows the appropriate graphs. Then a disadvantage is a lack of experimental work. Concerning this issue, the author refers to the publications in which the verification of the results of numerical simulation and experimental results has been conducted showing that their coinciding is quite accurate.