1-D modeling of transient engine operations using data generated by a CFD code

Document Type

Conference Proceeding

Publication Date



Department of Mathematical Sciences


Transient engine operations are modeled and simulated with a 1-D code (GT Power) using heat release and emission data computed by a 3-D CFD code (Kiva3). During each iteration step of a transient engine simulation, the 1-D code utilizes the 3-D data to interpolate the values for heat release and emissions. The 3-D CFD computations were performed for the compression and combustion stroke of strategically chosen engine operating points considering engine speed, torque and excess air. The 3-D inlet conditions were obtained from the 1-D code, which utilized 3-D heat release data from the previous 1-D unsteady computations. In most cases, only two different sets of 3-D input data are needed to interpolate the transient phase between two engine operating points. This keeps the computation time at a reasonable level. The results are demonstrated on the load response of a generator which is driven by a medium-speed diesel engine. This approach considerably improves the emissions-prediction capability of the 1-D code for transient engine operations, and thus improves the accuracy of standardized road test cycles.

Publisher's Statement

Copyright © 2008 SAE International. Publisher’s version of record: https://doi.org/10.4271/2008-01-0357

Publication Title

SAE Technical Papers