Investigation on the Lubrication Heat Transfer Mechanism of the Multilevel Gearbox by the Lattice Boltzmann Method

Abstract

In a gear transmission system in a closed space, the heat transfer between gears and fluids presents highly nonlinear characteristics due to the complex physical processes involved in heat exchange and fluid motion, and constructing and solving the thermodynamic model of the gearbox becomes a task that involves considerable difficulty. This paper takes a conical–cylindrical two-stage gearbox as the research object, proposes a fluid–solid coupled dynamics model based on the lattice Boltzmann (LBM) combined with the large eddy simulation (LES) method, and the adopted lattice model is the D3Q27 velocity model, which is used to numerically simulate the distribution of the flow field inside the gearbox and undertake in-depth research on the fluid motion law of the complex gear transmission system in the enclosed space. The model is solved to reveal the laws determining the gear speed and the effects of the lubricant’s dynamic viscosity and thermal conductivity coefficient on the gear heat dissipation efficiency. By adopting the lattice Boltzmann method, we can simulate the fluid flow and heat transfer inside the gearbox more efficiently, which provides a new way to closely understand the thermodynamic behavior of closed complex gear transmission systems. The application of this method is expected to provide strong support for thermal performance optimization and the design of gear transmission systems.