Effect of cylinder-liner rotation on wear rate: An experimental study.

In rotating cylinder-piston system, the largest losses source is frictional losses, accounting for 50% of the total frictional losses, thus it is important to optimize. Effect of incremental rotation of a cylinder liner on its wear rate was investigated. The engine speed, load and the cylinder rotating angle were the main parameter. The results showed that the wear rate may be reduced to the half simply by rotating cylinder liner every six hours' time interval of working. The test was carried out in pairs using a piston cylinder with movable liner and compared to a standard cylinder liner (fixed liner). Angles of 60o, 120o, 180o, 240o, and 300o were used for incremental movement. The same operating conditions for two cylinders were maintained for the purpose of comparison. Beneficial effects of reducing the wear rate for all components of the piston-cylinder arrangement associated with incremental rotational movement of a cylinder linear were noticed. A decrease in wear rate was obvious in the cylinder liner in rotation angles of 120o and 240o and it is almost one-fourth of the wear that occurs in the stationary cylinder liner.

Urban traffic pollution reduction for sedan cars using petrol engines by hydro-oxide gas inclusion.

UNLABELLED: Petrol cars, in particular nonhybrid cars, contribute significantly to the pollution problem as compared with other types of cars. The originality of this article falls in the direction of using hydro-oxy gas to reduce pollution from petrol car engines. Experiments were performed in city areas at low real speeds, with constant engine speeds in the average of 2500 rpm and at variable velocity ratios (first speed was 10-20 km/hr, second speed was 20-35 km/hr, and third speed was 35-50 km/hr). Results indicated that through using hydro-oxy gas, a noticeable reduction in pollution was recorded. Oxygen (O2) percentage has increased by about 2.5%, and nitric oxide (NO) level has been reduced by about 500 ppm. Carbon monoxide (CO) has decreased by about 2.2%, and also CO2 has decreased by 2.1%. It's worth mentioning that for hybrid system in cars at speeds between 10 and 50 km/hr, the emission percentage change is zero. However, hybrid cars are less abundant than petrol cars. IMPLICATIONS: The originality of this paper falls in the direction of using hydro-oxy gas to reduce pollution from petrol car engines. Experiments were performed in city areas at low real speeds, with constant engine speeds in the average of 2500 rpm and at variable velocity ratios (first speed was 10-20 km/hr, second speed was 20-35 km/hr, and third speed was 35-50 km/h).