Drag reduction and self-cleaning of a heavy vehicle with coating a lubricant infused slippery surface

Background.

The reduction of the aerodynamic drag of heavy vehicles is an important issue for improving fuel usage efficiency for cargo transportation and decreasing environmental pollution [1]. For a heavy vehicle, the friction drag is usually less than the form drag. However, since the length of heavy vehicles, especially container trucks, is much longer than that of passenger cars, the contribution of friction drag becomes important because the three flat surfaces of the container give rise to noticeable drag. Lubricant-infused surface (LIS) was recently introduced as a biomimetic slippery surface inspired by Nepenthes, a pitcher plant [2,3]. LIS has shown a good drag-reducing performance owing to the lubricant of LIS induces interfacial slip on the underwater surface. However, the effect of LIS on aerodynamic drag reduction for a heavy vehicle remains unclear. Therefore, this project aims to investigate whether LIS can reduce the frictional drag of a heavy vehicle and if so, by how significant the drag reduction is. In addition, the self-cleaning effect of LIS will be examined as another desirable feature.

IRES student involvement. 

A heavy vehicle model and drag force measurement system are already prepared in a large wind tunnel of POSTECH. Mr. J. Kim and an IRES student will discuss the experiment setup and coating of LIS surfaces, and measure the friction drag with and without LIS surfaces. A two-dimensional PIV (particle image velocimetry) measurement will be conducted to investigate the slippery flow features of the LIS surface of the heavy vehicle.

References

1. J.J. Kim et al., "Considerable drag reduction and fuel saving of a tractor–trailer using additive aerodynamic devices," Journal of Wind Engineering and Industrial Aerodynamics, vol. 191, pp. 54-62, 2019.
2. T.S. Wong et al., "Bioinspired self-repairing slippery surfaces with pressure-stable omniphobicity," Nature, vol. 477, no. 7365, pp. 443–447, 2011.
3. H.N. Kim, and S.J. Lee, "Shear-driven drainage of lubricant in a spherical cavity of lubricant-infused surface," Physics of Fluids, vol. 33, no. 12, 2021.