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Cover photos: Pictured here is a KIVA3V calculation of a modern, high-performance 4-valve gasoline engine with a pentroof combustion chamber. This is a cold-flow run at 1600 rpm, with a constant 98-kPA manifold pressure. The cross-sectional views are through one intake valve (left side of each picture) and one exhaust valve (right side of each picture). Because the intake and exhaust valves in this engine share the same physical space at different times in the engine cycle, the structured computing mesh must be continually adjusted to conform to the current valve configuration. The white lines show the mesh at the two extremes: when the intake valves are fully open (103" crank angle) and, later, when the exhaust valves are fully open (609" crank angle). The curved lines cutting through the ports are fictitious. Plotted in color is the turbulent kinetic energy. At 103", the highest turbulence levels induced in the cylinder by the incoming flow around the valve occur both off the near-side top surface and the far edge of the valve. At 609", the highest turbulence values are confined to the exhaust port.The initial computing mesh was created by the K3PREP parametric grid generator. The color plots were drawn with the General Mesh Viewer (GMV) graphics postprocessor, a public-domain program written at Los Alamos National Laboratory.

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