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One Dimensional Modeling

Abstract

The unsteady 1-D gas dynamics code uses the method of characteristics and predicts the gas exchange process and residual gas fraction in the internal combustion engine [1]. New approaches are presented for modeling flows in diverging ducts and for treating boundary conditions. These include the use of flow resistance correlation to describe separated flows and flows in bends. Excellent agreement with analytical solutions and test results has been obtained when the code was validated with fundamental gas dynamics problems, including: converging-diverging nozzle flows with and without shocks; Fanno and Rayleigh flows; the Riemann shock tube problem; and engine rig experiments for flows with different properties. The code has been applied satisfactorily to predict the gas exchange process following exhaust blow-down in a spark-ignition engine and the exhaust gas recirculation (EGR) levels in an heavy duty diesel engine.

[1] Zhu, Y. and Reitz, R.D. “A 1-D Gas Dynamics Code for Subsonic and Supersonic Flows Applied to Predict EGR Levels in a Heavy-Duty Diesel Engine,” Int. J. of Vehicle Design, Vol. 22, No. 3/4, pp. 227-252, 1999.

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Introduction (.pdf)

Executable, input and license files to be run on PC (Note that the current license expires on 12/30/2007)