STUDI PARAMETRIK PROSES PENYEMPROTAN BAHAN BAKAR DAN PEMBAKARAN PADA MOTOR DIESEL DENGAN SIMULASI 3-D

• Main Author: Budi Santoso (NIM : 23197007), Widodo
• Format: Theses
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/5014
• Institution: Institut Teknologi Bandung

<b>Abstract :</b><p align=\"justify\"> <br /> Parametric study offuel spray and combustion process on diesel engine has been carried out using FIRE CFD code. The model incorporates a k- ? turbulence model, a `wave\' breakup spray model, the Shell ignition model, the Magnussen turbulent combustion model, and a spray/wall impingement model that includes rebounding and breaking-up drops. NOx formation was modeled using extended Zeldovich mechanism, whilst soot modeling includes nucleation, surface growth and oxidation process. The study was carried out by varying swirl ratio, injection time, breakup time constant, piston wall temperature, computation initial condition and diesel operating condition. Cylinder temperature and pressure, fuel vapour concentration, NOx formation, soot and unburned hydrocarbon were observed. Simulation showed that NOx formation was strongly influenced by fuel vapour concentration and temperature. The maximum NOx concentration was found in the slightly lean mixture (equivalence ratio around 0.9) with high temperature. Soot occurred under high temperature and fuel rich conditions. The models used were able to predict exhaust gas changes due to swirl ratio, start of injection, breakup time constant, and load changes. Unburned hydrocarbon concentration change due to wall temperature change was not predicted properly by these models.