| 摘要 |
PCT No. PCT/GB95/02906 Sec. 371 Date Sep. 15, 1997 Sec. 102(e) Date Sep. 15, 1997 PCT Filed Dec. 12, 1995 PCT Pub. No. WO96/18813 PCT Pub. Date Jun. 20, 1996An intake system is described for a spark ignition internal combustion engine having ports per cylinder, which may lead to a common intake valve or two separate intake valves. One of the intake ports (12) is shaped to direct a first flow tangentially near the outer periphery of the cylinder and the other intake port (20) is shaped to direct a second, swirling, flow towards the center of the cylinder. The second swirling flow has the same direction of rotation as that of the first flow. Injectors (28) are provided for introducing fuel into the second swirling flow thereby producing within the cylinder a charge that is radially stratified with a combustible mixture concentrated near the center of the cylinder. The flow rates through the two intake ports may be varied independently and the relative angular momentum of the two flows at the boundary between the two flows in the cylinder determines the degree of mixing between the two flows, such mixing being operative to decrease the degree of stratification of the charge within the cylinder. |
