15-09-2017, 11:58 AM
The term six-stroke engine has been applied to a series of alternative designs of internal combustion engines that try to improve the traditional two and four stroke engines. Claimed benefits may include increased fuel efficiency, reduced mechanical complexity and / or reduced emissions. These engines can be divided into two groups based on the number of pistons that contribute to the six strokes.
In single-piston designs, the engine picks up lost heat from the four-stroke Otto cycle or Diesel cycle and uses it to drive an additional stroke of power and exhaust from the piston in the same cylinder in an attempt to improve fuel efficiency and / or help with engine cooling. The pistons in this type of six-stroke engine go up and down three times for each fuel injection. These designs use steam or air as working fluid for the additional power stroke.
Designs in which the six movements are determined by the interactions between two pistons are more diverse. The pistons may be opposed in a single cylinder or may reside in separate cylinders. Usually one cylinder makes two strokes while the other makes four strokes giving six piston strokes per cycle. The second piston can be used to replace the valve mechanism of a conventional motor, which can reduce the mechanical complexity and allow a higher compression ratio by eliminating hotspots that would otherwise limit the compression. The second piston can also be used to increase the expansion ratio, by disengaging it from the compression ratio. Increasing the expansion ratio in this way can increase thermodynamic efficiency in a manner similar to the Miller or Atkinson cycle.
Following video is better to understand the six stroke engine working :
In single-piston designs, the engine picks up lost heat from the four-stroke Otto cycle or Diesel cycle and uses it to drive an additional stroke of power and exhaust from the piston in the same cylinder in an attempt to improve fuel efficiency and / or help with engine cooling. The pistons in this type of six-stroke engine go up and down three times for each fuel injection. These designs use steam or air as working fluid for the additional power stroke.
Designs in which the six movements are determined by the interactions between two pistons are more diverse. The pistons may be opposed in a single cylinder or may reside in separate cylinders. Usually one cylinder makes two strokes while the other makes four strokes giving six piston strokes per cycle. The second piston can be used to replace the valve mechanism of a conventional motor, which can reduce the mechanical complexity and allow a higher compression ratio by eliminating hotspots that would otherwise limit the compression. The second piston can also be used to increase the expansion ratio, by disengaging it from the compression ratio. Increasing the expansion ratio in this way can increase thermodynamic efficiency in a manner similar to the Miller or Atkinson cycle.
Following video is better to understand the six stroke engine working :