Investigating the Behavior of Various Lubrication Regimes under Dynamic Conditions Using Nonequilibrium Molecular Dynamics

It is crucial to comprehend how the oil film varies under dynamic operating conditions and the accompanying friction properties to better grasp the friction mechanism and control friction behavior. To model the friction characteristics under boundary lubrication (BL) and elastohydrodynamic lubrication (EHL), nonequilibrium molecular dynamics simulations with various numbers of hexadecane molecules as lubricating oil were conducted in this research under the conditions of dynamic speed and dynamic load. All the dynamic operating conditions have the form of sine waves, with various frequencies and amplitudes. According to the findings, the friction force is strongly connected with interfaces where relative sliding takes place, whose number, velocity difference, and the degree of solidification have significant influences. The variation of amplitude under dynamic load can cause a regular change in the density of the lubricating layer, while the variation of frequency can cause a change in molecular layer’s range of motion. Both effects are crucial for friction. The structure of the lubricating layer with lower friction varies with various frequencies for dynamic velocity. Both high and small amplitudes of velocity offer advantages to form a stable film structure at low frequencies in the BL and EHL regions, while the amplitude in the BL area has minimal association with friction at high frequencies. At high frequencies in the EHL region, the friction rises as the amplitude of velocity grows and the lubricating layer becomes more unstable

Impact of carbon cap and carbon credit prices on environmental objective.

Impact of carbon cap and carbon credit prices on environmental objective.</p

Typical Pareto solutions of inventory allocation planning problem.

Typical Pareto solutions of inventory allocation planning problem.</p

Simulation results of large scale problem.

Simulation results of large scale problem.</p

Simulation result.

(A) Pareto frontier of economic and environmental objectives. (B) Purchase quantities of materials with different Xpj.</p

Purchasing information of materials.

Purchasing information of materials.</p

Results of Taguchi experiments.

(A) SNR graph from the Taguchi experiments. (B) Mean graph from Taguchi experiments.</p

The levels for each of the parameters.

The levels for each of the parameters.</p

Impact of carbon emission.

(A) Environmental cost under different carbon caps. (B) Floating of environmental cost with different carbon credit prices.</p

The flow of materials in supplier–manufacturer network.

The flow of materials in supplier–manufacturer network.</p