Assessment of the Time Step in the Modeling of Cold Flow in a Motored Diesel Engine 2010-36-0090
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.
Citation: Zancanaro 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. Download Citation
Author(s):
Flavio V. Zancanaro Jr., Horacio A. Vielmo
Affiliated:
Federal University of Rio Grande do Sul
Pages: 13
Event:
SAE Brasil 2010 Congress and Exhibit
ISSN:
0148-7191
e-ISSN:
2688-3627
Related Topics:
Diesel / compression ignition engines
Computational fluid dynamics
Wind tunnel tests
Simulation and modeling
Pistons
Turbulence
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