In-Cylinder Flow CFD Analysis of a Four-Valve Spark Ignition Engine: Comparison Between Steady and Dynamic Tests

Numerical and experimental techniques were applied in order to study the in-cylinder flow field in a commercial four-valve per cylinder spark ignition engine. Investigation was aimed at analyzing the generation and evolution of tumble-vortex structures during the intake and compression strokes, and the capacity of this engine to promote turbulence enhancement during tumble degradation at the end of the compression stroke. For these purposes, three different approaches were analyzed. First, steady flow rig tests were experimentally carried out, and then reproduced by computational fluid dynamics (CFD). Once CFD was assessed, cold dynamic simulations of the full engine cycle were performed for several engine speeds (1500 rpm, 3000 rpm, and 4500 rpm). Steady and cold dynamic results were compared in order to assess the feasibility of the former to quantify the in-cylinder flow. After that, combustion was incorporated by means of a homogeneous heat source, and dynamic boundary conditions were introduced in order to approach real engine conditions. The combustion model estimates the burning rate as a function of some averaged in-cylinder flow variables (temperature, pressure, turbulent intensity, and piston position). Results were employed to characterize the in-cylinder flow field of the engine and to establish similarities and differences between the three performed tests that are currently used to estimate the engine mean flow characteristics (steady flow rig, and cold and real dynamic simulations). DOI: 10.1115/1.4000265

[1]  Rolf D. Reitz,et al.  An ignition and combustion model based on the level-set method for spark ignition engine multidimensional modeling , 2006 .

[2]  Chung-Hwan Jeon,et al.  Effects of Intake Ports on In-Cylinder Flow and Lean Combustion in a 4-Valve Engine , 1998 .

[3]  Carlo N. Grimaldi,et al.  Experimental and Numerical Analysis of Charge Motion Characteristics Depending on Intake Valves Actuation Strategies , 2005 .

[4]  Seung-Hyun Lee,et al.  CORRELATION STUDY OF THE MEASURED TUMBLE RATIOS USING THREE DIFFERENT METHODS: STEADY FLOW RIG; 2-DIMENSIONAL PIV; AND 3-DIMENSIONAL PTV WATER FLOW RIG , 2006 .

[5]  Carlo N. Grimaldi,et al.  Dependence of Flow Characteristics of a High Performance S.I. Engine Intake System on Test Pressure and Tumble Generation Conditions - Part 1: Experimental Analysis , 2004 .

[6]  Enrico Mattarelli.  Comparison Between Two Combustion Chambers for a Motorcycle Racing Engine , 2000 .

[7]  Elio Jannelli,et al.  Influence of the Intake System Design on a Small Spark-Ignition Engine Performance A Theoretical Analysis , 2003 .

[8]  Ezequiel J. López,et al.  Validation of a 0D/1D computational code for the design of several kind of internal combustion engines , 2010 .

[9]  Gian Marco Bianchi,et al.  The Influence of Stroke-to-Bore Ratio and Combustion Chamber Design on Formula One Engines Performance , 1998 .

[10]  C. W. Hong,et al.  In-Cylinder Tumble Flow Field Measurements and Predictions , 2001 .

[11]  Oliver Lang,et al.  Direct Injection Gasoline Engines - Combustion and Design , 1999 .

[12]  Hua Zhao,et al.  Effects of Intake Valve Timing on Premixed Gasoline Engine with CAI Combustion , 2004 .

[13]  Carlo N. Grimaldi,et al.  Flow Characterization of a High Performance S.I. Engine Intake System - Part 1: Experimental Analysis , 2003 .

[14]  Liguang Li,et al.  Effects of Intake Valve Closing Timing on Gasoline Engine Performance and Emissions , 2001 .

[15]  Norberto M. Nigro,et al.  Assessment of a zero‐dimensional model of tumble in four‐valve high performance engine , 2007 .

[16]  O. Bailly,et al.  Simulation of the Intake and Compression Strokes of a Motored 4-Valve Si Engine with a Finite Element Code , 1999 .

[17]  P. Aleiferis,et al.  The nature of early flame development in a lean-burn stratified-charge spark-ignition engine , 2004 .

[18]  C. Dopson,et al.  Asymmetric Valve Strategies and Their Effect on Combustion , 1993 .

[19]  Zdeněk Johan,et al.  In-cylinder cold flow simulation using a finite element method , 2001 .

[20]  Jun Qiao,et al.  A CFD Investigation into the Effects of Intake Valves Events on Airflow Characteristics in a Motored 4-Valve Engine Cylinder with Negative Valve Overlapping , 2007 .

[21]  Mario A. Storti,et al.  Simultaneous untangling and smoothing of moving grids , 2008 .

[22]  M. Metghalchi,et al.  Burning Velocities of Mixtures of Air with Methanol, Isooctane, and Indolene at High Pressure and Temperature , 1982 .

[23]  G. Fontana,et al.  The Influence of Variable Valve Timing on the Combustion Process of a Small Spark-Ignition Engine , 2006 .

[24]  Ulrich Spicher,et al.  Investigation of the Bowl-Prechamber-Ignition (BPI) Concept in a Direct Injection Gasoline Engine at Part Load , 1999 .

[25]  Hongming Xu,et al.  SOME CRITICAL TECHNICAL ISSUES ON THE STEADY FLOW TESTING OF CYLINDER HEADS , 2001 .

[26]  D. A. Santavicca,et al.  The Fractal Nature of Premixed Turbulent Flames , 1990 .

[27]  F. Gouldin.  An application of fractals to modeling premixed turbulent flames , 1987 .

[28]  Michele Cavalletti,et al.  Dependence of Flow Characteristics of a High Performance S.I. Engine Intake System on Test Pressure and Tumble Generation Conditions - Part 2: Numerical Analysis , 2004 .