Ignition by air injection (CIBAI) for controlled auto-ignition in a CFR engine.

摘要

Compression ignition by air injection (CIBAI) has been successfully achieved in a modified single cylinder, four-stroke, spark ignition cooperative fuel research (CFR) engine. The CIBAI cycle was invented by Professor John Loth and Professor Gary Morris, US patent No's: 6,994,057 Feb. 7, 2006 and 6,899,061 May 31, 2005. This new revolutionary combustion concept has the potential to become an alternative to traditional (SI) spark ignited and compression ignited (CI) diesel engines.;The objective of this dissertation was to demonstrate experimentally the viability of achieving ignition by air injection (CIBAI) for controlled auto-ignition in a CFR engine. This experimental work involved the development of an air injection model, and the design, assembly, and testing of a highly specialized air injection and timing equipment. These experiments were designed to substitute CIBAI ignition for one cycle in a spark ignition engine. The CIBAI engine cycle analysis is included, followed by an analytical model of the air injection process. A controller for the air injection and timing system had been designed, built and tested under different operating conditions until a satisfactory experimental procedure was developed for testing using the CIBAI concept. Based on the measured pressure-time history a numerical modeling code was developed to analyze power and combustion parameters (indicated net work, indicated mean effective pressure (IMEP), net heat release, net heat release rate, mass fraction burned (MFB), temperature history, combustion duration, and ignition delay). Finally, a parametric study was conducted to determine the effect of compression ratio, intake temperature, air-fuel ratio, air preheated charging pressure, and air-injection timing on CIBAI combustion.;Experimental and numerical model results indicated that ignition is readily achieved by air injection (CIBAI) in a CFR engine using the proper air injection system and proper air injection timing strategy.