09-04-2012, 04:24 PM
Cold Flow Simulation Inside an SI Engine
In_Cylinder_FLUENT_tut.pdf (Size: 747.18 KB / Downloads: 131)
Introduction
The purpose of this tutorial is to illustrate the case setup and solution of the two dimensional,
four stroke spark ignition (SI) engine with port injection.
SI engines are of extreme importance to the auto industry. The eciency of an SI engine
depends on several complicated processes including induction, mixture preparation, combustion,
and exhaust
ow. CFD analysis has been used extensively to improve each of
these processes. This tutorial simulates the intake, compression, expansion, and exhaust
processes without fuel combustion. Port injection is modeled and evaporation of fuel
droplets is simulated. The interaction of the fuel spray with the intake valve is modeled
through the wall lm modeling features available in FLUENT.
This tutorial demonstrates how to do the following:
Use of the In-Cylinder model for simulating reciprocating engines.
Use general strategies for modeling valve opening and closing.
Use of the Discrete Phase Model (DPM) for simulating port injection.
Carry out solver setup and perform iterations.
Examine the results.
Display and create animation for droplet injection.
Problem Description
The IC engine simulation is probably one of the most interesting engineering problems
in the eld of computational
uid dynamics. Port injection is used for ecient air/fuel
mixing and fuel distribution in multi-cylinder engines.
In this tutorial, you will consider a two dimensional engine with inlet and exit valves. The
engine is running at 2000 rpm.
Mesh Motion Setup
(a) Enable Dynamic Mesh in the Models list.
(b) Enable In-Cylinder in the Models list.
Enabling the In-Cylinder option allows input for IC-specic needs, including
valve and piston motion.
© Enable Smoothing, Layering, and Remeshing in the Mesh Methods group box.
(d) Click the Smoothing tab.
Summary
Use of In-Cylinder model capabilities has been illustrated for cold
ow simulation inside
the SI engine. All, suction, compression, expansion and exhaust strokes are simulated.
The Discrete Phase Model is used for simulating fuel injection, evaporation, and droplet
boiling.