Load carrying capacity and friction of an inclined parabolic-flat piston ring

Reducing the fuel consumption of a combustion engine has been an important design issue. Engine friction has to be reduced and the piston ring-cylinder liner contact is a major source of friction. The current work analyses the friction and load carrying capacity of an inclined parabolic-flat piston ring. This relatively simple geometry permits an analytical solution of the pressure distribution, the load carrying capacity and the friction. The friction coefficient is given as a function of twist angle, flat width and total width. The analytical expressions allow many thousands of calculations per second.