In this study, the effect of nanostructure morphology on bubble nucleation of liquid argon on a platinum solid surface was explored using molecular dynamics methods. We examined the differences in nucleation behavior on smooth and nanostructured surfaces, including trapezoidal, rectangular, and reentrant cavities. The simulation results demonstrated that nanostructured surfaces outperformed smooth surfaces in terms of bubble nucleation, and the corresponding morphology had a significant effect. The reentrant cavity had the shortest bubble initial nucleation time, followed by the rectangular cavity, and the trapezoidal cavity had the longest bubble initial nucleation time. The mechanism of bubble nucleation on solid surfaces was further investigated from two perspectives: heat transfer through the solid–liquid interface and the potential energy constraint. Compared with other surfaces, surfaces with reentrant cavities exhibited a significantly higher heat transfer efficiency. The liquid atoms on the nanostructured surfaces absorb a large amount of heat within a short time, resulting in rapid accumulation of heat in the cavity. The thermal motions of the liquid atoms are enhanced, and the potential energy constraints from the surrounding atoms are overcome to achieve rapid bubble nucleation. Thus, the nanostructures promote bubble nucleation in the heated liquid. Our results provide novel insights into the design of nanostructures to improve the boiling heat transfer performance.

To reduce emissions and save energy, alternative fuel and dual-fuel mode have been widely applied in the field of diesel engines. The pilot injection has potential to reduce engine vibration noise and pollutant emissions. The effects of a diesel fuel pilot injection strategy on the performance of an ethanol/F-T diesel dual-fuel engine were experimentally investigated on a four-cylinder four-stroke common rail diesel engine modified with an ethanol injection system. The results indicate that the variation in the combustion characteristic parameters with pilot injection timing is nonlinear and the difference is small, while soot, NO_x, and CO tend to decrease, with an increase in pilot injection timing. With the increase in pilot injection amount, p_max, combustion duration, CO and soot increased; p_max phase and CA50 were closer to TDC; HRR_max and the ignition delay period decreased. The BSFC tends to increase with the increase in pilot injection timing and the increase in pilot injection amount, while the BTE shows the opposite trend. The value and the variation range of COV_pmax are small. The effect of the pilot injection amount on ethanol/F-T diesel dual-fuel engine is more significant. The research presented in this paper can provide reference directions for the formulation of a fuel injection strategy of ethanol/F-T diesel dual-fuel combustion mode to reduce NO_x without worsening the combustion process and presenting an insufficient fuel economy.