A numerical study on the mechanism of reverse flow in a channel without obstruction at the entry

It is known that reverse flow occurs in a channel when there is an obstruction at the entry. However, it has been recently shown that the reverse flow can be realised even without an obstruction. This is achieved when the two sides of the channel have a stagger and are kept at an angle of attack to the free stream. The features of the computed reverse flow agree with the experimental results. The computations show that the pumping mechanism of reverse flow in the present case can be explained by the relatively lower pressure near the entry to the channel and the slightly higher pressure near the exit of the channel. The low pressure region, near the entry to the channel, having staggered walls and kept at an angle of attack, is generated by the flow separation at the leading edge of the bottom wall of the channel.