| 摘要 |
PURPOSE:To reduce the flow loss in the intake and exhaust passages of an internal combustion engine, by providing recesses and protrusions on the inner and outer portions of the inside central parts of curved sections of the passages. CONSTITUTION:When the intake and exhaust of a four-cycle internal combustion engine have reaches the curved sections 7, 9 of passages, vortexes would be caused, due to the separation of boundary layers, from points C', A' on the outer portions 7', 9' of the insides of the passages and the inner portions 7'', 9'' of the insides of the passages. Spherical recesses 10 provided downstream to the points C', A' act so that the boundary layers of intake and exhaust flows are forcedly changed into turbulent boundary layers of higher energy. Groups of fluid molecules with high kinetic energy rush into the turbulent boundary layers to eliminate backward flows. As a result, the boundary layers are kept from being separated. |
