Instabilities of flows in helical pipes

Gelfgat, 2020, Fluid Dynamics Research, to appear

 

Definitions for the helical pipe

centerline:  

curvature:  

torsion:      

Dimensionless curvature:     

Torsion to curvature ratio:

 

Reynolds number: - known only after the flow is calculated

 

Assume pressure gradient is known.

D

T

 

Germano coordinates

Governing equations in Germano coordinates

Comparison with experiments: friction factors

Steady flow patterns

Comparison with experiments: stability

Neutral curves

Disturbance modes and animations

 

top    close