Effect of natural gas direct injection (NGDI) on the performance and knock behavior of an SI engine

• The influence of natural gas direct injection on gasoline port engine is investigated. CO and 2 emissions reduced when R CNG increased. RI decreased by 88.6 % for = 100 CR 12.5 compared to pure gasoline. Addition 25 the knock occurrence significantly. unique properties (NG), including high availability lower cost with other fossil fuels, make it attractive in internal combustion (ICE) application. NG composed mainly methane has greater resistance than gasoline, enabling higher compression ratios (CR). In contrast distinctive advantages, fueled engines suffer from power torque outputs. To address subject, this study proposes an approach employing (NGDI) strategy (with volumetric efficiency unlike injection), a irrespective limit. This work applies reactive computational fluid dynamics (CFD) investigate spark ignited co-combustion direct-injected port-admitted results are validated against experimental data. all simulated cases, equivalence ratio (i.e., ? 1) total input energy kept constant. Engine performance evaluated three CRs (10.5, 11.5, 12.5:1), five proportion (R ) at part- full-load conditions speed 1500 rpm. Results indicated that while running 10.5:1, carbon monoxide (CO) dioxide (CO were 29.3 23.5 respectively, 0 %. corresponding emission reduction 11.5:1 was 27.1 24 %; 12.5:1 they 29.6 respectively. At each CR, intensity full load fell significantly as percentage 12.5:1, ringing (RI) using %, instead Under same conditions, cut 56