A Novel Approach for Simultaneous NOx and Smoke Reduction: Interacting-Sprays Injection 961678
In the past decade many in-cylinder approaches were proposed for simultaneous reduction of NOx and smoke with various degrees of success in operation. In this paper, results from a novel and promising technique referred to as Interacting-Sprays injection concept is presented. A single-cylinder compression-ignition two-stroke research engine with optically-accessible head, mounted on a high-speed CFR engine crankcase was used to investigate the combustion and emission characteristics of this injection system. The Interacting-Sprays injection system produces two separate independently-control led sprays with a good degree of adjustability with regard to their fuel quantities and injection timings. The impingement schedule of the two sprays on each other at the right time and place in the combustion chamber is the key to the success of the Interacting-Sprays system. Results are presented to show the effects of the varied injection system characteristics on the combustion and exhaust emissions ( NOx and smoke). The effects of the injection timing and time separation between the first and second injections of the Interacting-Sprays injection system are explored. Conditions are identified for which a favorable influence on both smoke and NOx production is observed. A promising and new injection system and strategy are therefore proposed as a result of the data acquired in this study.