抄録
Engines the bore of which is much longer than the stroke have a potential of high performance engines because flow loss can be much reduced. To examine the possibility of heat transfer enhancement we visualized the flow in such situation. The hydrogen bubble method is used for the corresponding condition as 1MPa, 600K hydrogen gas. A pair of vortexes forms on the both side of channel. It, once weakened near the bottom dead center, is strong then by the flow coming along the displacer upper surface when the fluid is sucked into the channel.
