The static back pressure at the pressure outlet causes an
adverse pressure gradient inside the inlet where the boundary layer conditions are the function of this boundary condition.
In the stenotic TRA, pressure reached to a high level ahead the stenosis, promptly decreased to the trough level at the stenosis throat, and then slightly increased at downstream stenosis leading to an
adverse pressure gradient. Similar phenomena were observed at both diastole and systole phases.{Figure 1}
Also flow separates at the entrance of valve neck because of
adverse Pressure gradient increases with increase in valve Neck because the change of valve shape.
Especially near the die lip, where the no-slip condition dictates the fluid to stop, the shear rate locally increases significantly, when the wet film thickness is small enough to induce a strong
adverse pressure gradient. In this study, however, the final wet thickness is half of the downstream gap height ([R.sub.gt] = 2) in the computations considered, which causes Couette flow in the coating gap, and the viscosity under the die lip become virtually constant at a steady state, as shown in Fig.
Figure 12 is sectored so that the upper right-hand quadrant denotes the region of peristaltic pumping where [bar.Q] > 0 (positive pumping) and [DELTA]p > 0 (
adverse pressure gradient).
Turbulent boundary layers are more stable than laminar layers under conditions of an
adverse pressure gradient, and consequently the turbulent flow remains attached to the rear half of the ball considerably longer, resulting in a significantly narrower wake.
As the top roll's speed rises, the meniscus moves toward the gap, and an
adverse pressure gradient is formed.
The change in flow topology in the diffuser is related to the positive slope; reverse flow and
adverse pressure gradient are thereby introduced to evaluate the onset and development of rotating stall within the diffuser.
With the external shock system moving upstream, the augment of
adverse pressure gradient caused by increasing spillage accelerates the reversed flow.