階梯的流場運用的十分廣泛，因此對於不同外因使得流場現象有所改變，均值得加一探討。除了不同流速與幾何外形之外，本文是以不同的噴流位置及強度，瞭解噴流對於迴流區所產生的影響。迴流區內的噴流對於質量及能量上均有正面的幫助，可以使得混合效果增加。而迴流區外的噴流則因其強度而有不同之影響，如迴流區外較強之噴流，反而有助於散熱方面的應用。 Backward-facing step is quite useful in a lot of field, and it is worthy to discuss the influences when the shape changes. Besides the velocity and different shapes, we plant an injection on the bottom side of step with different velocity of injection and different location to realize how they effect the fluid field. Because of the increasing of the mass and energy, the injection in the recirculation makes the mixture better. When the injection locates on the outer recirculation, the effect on the fluid field depends on the strength of the injection. If the stronger injection locates on outer recirculation, it takes good advantages in heat transfer.
