- #1
komega
- 2
- 0
Hi,
I'm new here so I'd like to apologise in advance if this has been posted before. I tried searching first but nothing came up.
I'm doing a project on subsonic, compressible flow in curved ducts and have a question about the physics involved as the flow navigates a bend. Allow me to further simplify the problem by stating that the curvature is mild to avoid separation and that the flow is bounded by two infinite plates (top and bottom). I understand that secondary flows play a significant part in internal flows but for now, I would like to constrain my discussion to the primary or bulk flow per say. As the flow turns, a radial pressure gradient is generated that results in the flow decelerating near the concave side (outer wall) and accelerating (for the initial part) near the convex side (inner wall).
So my question is essentially: How is this radial pressure gradient generated? (I guess one may assume an ideal flow for the purpose of explanation)
I have encountered various ways of explaining it (among them/combination of; Bernoulli's equation normal to the flow direction, mass/momentum continuity, Coanda effect) but have arrived at the "chicken-and-egg" situation. Most references I tried usually highlighted the balance between centrifugal and pressure forces. I would appreciate it if anyone would kindly shed some light on my situation. Apologies if I have not fully clarified the problem.
Thanks,
Dave
I'm new here so I'd like to apologise in advance if this has been posted before. I tried searching first but nothing came up.
I'm doing a project on subsonic, compressible flow in curved ducts and have a question about the physics involved as the flow navigates a bend. Allow me to further simplify the problem by stating that the curvature is mild to avoid separation and that the flow is bounded by two infinite plates (top and bottom). I understand that secondary flows play a significant part in internal flows but for now, I would like to constrain my discussion to the primary or bulk flow per say. As the flow turns, a radial pressure gradient is generated that results in the flow decelerating near the concave side (outer wall) and accelerating (for the initial part) near the convex side (inner wall).
So my question is essentially: How is this radial pressure gradient generated? (I guess one may assume an ideal flow for the purpose of explanation)
I have encountered various ways of explaining it (among them/combination of; Bernoulli's equation normal to the flow direction, mass/momentum continuity, Coanda effect) but have arrived at the "chicken-and-egg" situation. Most references I tried usually highlighted the balance between centrifugal and pressure forces. I would appreciate it if anyone would kindly shed some light on my situation. Apologies if I have not fully clarified the problem.
Thanks,
Dave