Flow Structure and Mixing in a Motored Axisymmetric Engine

Observations of the in-cylinder flow field have been made using a smoke flow visualization technique in a transparent cylinder axisymmetric motored engine. The engine incorporates variable valve timing and variable swirl hardware. The visualization system utilizes a copper vapor laser, 16mm high speed camera and titanium dioxide smoke.

Three intake valve lift profile shapes were studied at 500 and 1000 RPM with and without swirl. Observed flow patterns change rapidly near TDC. Axial stratification is produced with swirl during intake but is destroyed during compression. A valve curve was found which accelerates in-cylinder mixing relative to a standard curve.