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A steady-state flowbench measures the mass and angular momentum flux (swirl and tumble) for a given cylinder head intake port design over varying valve lifts and pressure drops. From these two measurements, enhancements in volumetric efficiency and burnrate can be determined. This methodology, however, requires the production and experimental testing of multiple cylinder head castings or soft-prototypes. To help reduce the number of hardware design iterations, an analytical methodology has been developed which uses a new computational fluid dynamics (CFD) simulation tools called PowerFLOW. From a solid model of the cylinder head, PowerFLOW uses automeshing which produces a 10 million Cartesian volume mesh in 4 CPU hrs. The lattice Boltzmann technique used by PowerFLOW is inherently parallel resulting in steady-state results on this mesh in 36 CPU hrs. This paper present a comparison of numerically obtained mass flow rates from PowerFLOW to experimental flowbench data.

Accurate prediction of engine combustion characteristics, especially burn rates, can eliminate a number of hardware iterations, thus resulting in a significant reduction in design and developmental time and cost. An analytical methodology has been developed which allows the determination of part-load MBT spark timing to within 2 crank-angle degrees. The design methodology employs the in-house-developed steady-state quasi-dimensional engine simulation model (GESIM), coupled with full-field measurement of the in-cylinder fluid motion at bottom dead center (BDC) in the computer-controlled water analog system (AquaDyne). The in-cylinder flow-field measurements are obtained using 3-D Particle Tracking Velocimetry (3-D PTV), also developed in-house. In this methodology, the in-cylinder flow measurement data are used to calibrate both the tumble and swirl models in GESIM.