This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Assessment of the Time Step in the Modeling of Cold Flow in a Motored Diesel Engine
ISSN: 0148-7191, e-ISSN: 2688-3627
Published October 06, 2010 by SAE International in United States
Annotation ability available
The work investigates the effects of the time step in the modeling of the intake and in-cylinder systems of a diesel engine, under the motored condition. The engine has a bore of 79.5 mm and a stroke of 86 mm. The valves and piston movements are included. The equations are numerically solved, including a transient analysis of the intake stroke, for an engine speed of 1500 rpm, using a commercial Finite Volumes CFD code. For the purpose of examining the in-cylinder turbulence characteristics two parameters are observed: the discharge coefficient and swirl ratio. Regarding the turbulence, computations are performed with the Reynolds-Averaged Navier-Stokes, Eddy Viscosity Model k-ω SST, and also the k-ε standard cubic model (usual in the automotive industry), with standard near wall treatment. A moving hexahedral mesh independence study is presented. In the same way many convergence tests are performed, and a secure criterion established. The enthalpy equation is also solved, and the air compressibility is considered, being treated as perfect gas. A steady state flow-bench intake calculation is also presented, and the results are compared against experimental data. Thought the results it is possible to note divergences between the turbulence models employed and time steps.
CitationZancanaro Jr., F. and Vielmo, H., "Assessment of the Time Step in the Modeling of Cold Flow in a Motored Diesel Engine," SAE Technical Paper 2010-36-0090, 2010, https://doi.org/10.4271/2010-36-0090.
- Bianchi, G.M., Cantore, G., Fontanesi, S., “Turbulence Modeling in CFD Simulation of ICE Intake Flows: The Discharge Coefficient Prediction,” SAE Technical Paper 2002-01-1118, 2002, doi:10.4271/2002-01-1118.
- Bianchi, G.M., Fontanesi, S., “On the Applications of Low-Reynolds Cubic k-ε Turbulence Models in 3D Simulations of ICE Intake Flows,” SAE Technical Paper 2003-01-0003, 2003, doi:10.4271/2003-01-0003.
- Bianchi, G.M., Cantore, G., Parmeggiani, P., Michelassi, V., On Application of Nonlinear k-ε Models for Internal Combustion Engine Flows. Transactions of the ASME vol. 124, pp. 668-677, 2002.
- Baratta, M., Catania, A.E., Pesce, F.C., Spessa, E., Vielmo, H.A., Numerical Analysis of a High Swirl-Generating Helical Intake Port for Diesel Engines. Proceedings of the 12th Brazilian Congress of Thermal Engineering and Sciences, Belo Horizonte, Brazil, 2008.
- Fiat Research Center; Consiglio Nazionale delle Ricerche, Motore Monocilindro Diesel con Distribuzione a 2 Valvole e Protezioni Termiche Camera di Combustione, Contract N° 82.00047.93, 1982(in italian).
- Fiat Research Center; Consiglio Nazionale delle Ricerche, Metodologia per la Caratterizzazione dei Condotti di Aspirazione Motori in Flusso Stazionario”. Contract N° 82.00047.93, 1983 (in italian).
- Baratta, M., Catania, A.E., Pesce, F.C., Spessa, E., Rech, C., Zancanaro, F.V.Jr., Vielmo, H.A., Transient Numerical Analysis of a High Swirled Diesel Engine”, 20th International Congress of Mechanical Engineering, Gramado - RS, Proceedings of COBEM, Rio de Janeiro, RJ: ABCM, 2009.
- Warsi, Z.V.A., Conservation Form of the Navier-Stokes Equations in General Nonsteady Coordinates, AIAA Journal, 19, pp. 240-242, 1981.
- Hinze, P.O., Turbulence, 2nd Edition, McGraw-Hill, New York, 1975.
- Jones, W.P., Prediction Methods for Turbulent Flow, Hemisphere, Washington, D.C., pp. 1-45, 1980.
- Launder, B.E. and Spalding, D.B., The Numerical Computation of Turbulent Flows, Computational Methods in Applied Mechanics and Engineering, 3, pp. 269-289, 1974.
- El Tahry, S.H., k-ε Equation for Compressible Reciprocating Engine Flows”, AIAA J Energy, 7(4), pp. 345-353, 1983.
- Rodi, W., Influence of Buoyancy and Rotation on Equations for the Turbulent Length Scale, Proc. 2nd Symp. on Turbulent Shear Flows, 1979.
- Menter, F.R., Zonal Two Equation k-ω Turbulence Models for Aerodynamic Flows Proc. 24th Fluid Dynamics Conf, Orlando, Florida, USA, Paper No. AIAA 93-2906, 1993.
- Tindal, M.J., Williams, T.J., Aldoory, M., The Effect of Inlet Port Design on Cylinder Gas motion in Direct Injection Diesel Engines, ASME, Flows in Internal Combustion Engines, pp. 101-111, 1982.
- Wilkes, N.S. and Thompson, C.P., An Evaluation of Higher-order Upwind Differencing for Elliptic Flow Problems, CSS 137, AERE, Harwell, 1983.
- Heywood, J.B., Internal Combustion Engines, McGraw-Hill Inc, 1988.
- Ferrari, G. Motori a Combustione Interna, Torino, Ed il Capitello, 2005 (in italian).
- Star-cd/es-ice User Guides, CD-adapco, 2008.