Friction has been a challenge for the mankind throughout the whole history since it resists the motion. It resists the transportation of goods. And transportation shares 20% of the global energy consumption and approximately 18% of the greenhouse gas emissions. Out of this share, road transportation builds up to 72% of the total energy consumed by the transportation sector. And the passenger cars share 45% of the energy use and emissions.
A recent report on the energy consumption due to friction losses in passenger cars by Kenneth Holmberg et al. estimates that only 21.5% of the potential fuel energy is used to move the car, whereas direct frictional losses account for 33% (28% if breaking is excluded). Within these losses, 35% is used to overcome tire-road friction, 35% to overcome engine friction, 15% – transmission and 15% brake contact friction.
The authors also estimated the potential benefits from the tribological research and implementation of the new solutions to reduce the friction. They calculate that a “Car-2010”, with the most sophisticated tribological technology available today, if implemented in all existing cars, the frictional energy losses can be reduced 42% and 37% of global fuel consumption. And the forecast for the “Car-2020”, which has to come with the R&D activity in tribology, states that the fuel consumption would be reduced by 70% from today’s levels. The tribological means for the friction reduction according to the authors, include implementation of coatings, texturing and use of low-viscous lubricants.
These and many other interesting details can be found in the original article by Kenneth Holmerg, Peter Andersson and Ali Erdemir.
Credit for image: CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=29211.