Effect of Direct Injection Diesel Engine Convert to Sequential Injection CNG Engine in Intake Port Gas Flow Pressure Profile


1 Mechanical Engineering, University Malaysia Pahang

2 Mechanical Engineering, Universiti Malaysia Pahang

3 Marine Engineering, Institut Teknologi Sepuluh Nopember


The one dimension computational model of a sequential injection engine, which runs on compressed natural gas (CNG) with spark ignition, is developed for this study, to simulate the performance of gas flow pressure profile, under various speed conditions. The computational model is used to simulate and study of the steady state and transient processes of the intake manifold. The sequential injection CNG engine model is developed using GT-Power software. The size of this model engine is developed from the real diesel engine data and was input into the software's' library. The simulation model engine runs with various speeds from 1000 up to 4000 rpm. The simulation results of the performance with gas flow pressure, in the intake manifold are collected from two data sets; the GT-Post post processing plots for pressure performance versus crank angle, and post processing cases RLT for pressure performance versus engine speed. The simulation results of the intake manifold and the performance of the gas flow pressure profile, with various engine speed, for the CNG sequential injection engine are shown by characters. The Pressure profile of the engine and the numerical accuracy of the model is verified and validated by comparing the average total of the intake manifold pressure, with the measured intake manifold pressure, of a CNG sequential injection engine. The simulation results show that, the conversion of diesel engine to a CNG sequential injection engine with spark ignition will increase the pressure performance in the intake manifold of the engine.