Since the commercialization of the car internal combustion engine the mechanism was related to pistons that turned a crankshaft linked to a camshaft to open and close the valves and this directed the flow of air into or out of the cylinder. With such a mechanism the timing was restricted with the movement of the pistons and thus the tuning could be done till a certain limit.
Purdue’s scientists have created first computational model to track engine performance from one combustion cycle to the next for a new type of engine that could dramatically reduce oil consumption and the emission of global-warming pollutants.
In this concept, known as variable valve actuation intake and exhaust valves are no longer driven by mechanisms connected to the pistons which eliminates the need to link crankshaft to the camshaft, providing an independent control system for the valves so that they can be more finely tuned and hence leads to more efficient combustion of diesel, gasoline and alternative fuels, such as ethanol and biodiesel.
Moreover, the technique has also enable the introduction of an advanced method called homogeneous charge compression ignition, or HCCI that would make it possible to improve the efficiency of gasoline engines by 15 percent to 20 percent.
The system will also have a major contribution towards fighting the global warming issue as it will reduce the emission of two other harmful gases contained in exhaust: global-warming carbon dioxide and unburned hydrocarbons. A portion of exhaust can be rerouted to the cylinder for better combustion efficiency and even the amount of compression can be varied.
Via: slashdot
