Abstract
This paper starts from the investigations of the two problems about the attached flow written below:
(1) The experimental results show the non-uniformity of the pressure distribution in the bubble, so the radius of the center line of the reattaching jet must not be constant as is commonly assumed in most papers.
(2) Though the novel theories on models such as the attachment point model, the control volume model and some modification of them have their foundations on the momentum law of fluid, the models are inconsistent.
Moreover, in these models σ (Görtler jet-spread parameter) has to change widely from 1 to 20 across σ0=7.67 (free jet), even though the phenomenon is only a “reattachment”.
First, we intend to take the return flow from the attachment point into consideration: this flow brings pressure recovery near the offset-wall and yields the non-uniform pressure distribution in the bubble. The pressure ratio Cp is introduced again to evaluate the distribution.
Next, the curvature of the center line of the attached flow is changed by the values of Cp. An exponentially decreasing radius has been adopted for an example.
Finally a simple model is illustrated to calculate the attachment point distances using constant parameters (Cp=2, σ=7.67) resulting fairly good agreement with experimental data.
