Shear flows in shallow water: Foundation and accuracy of the rigid-lid assumption
Abstract
Linear stability analysis of lateral motions in open channel flows is frequently performed under the rigid-lid assumption. The objective of this paper Is to study the foundation of the rigid-lid assumption and determine its accuracy. It is shown that implicit in the rigid-lid approximation is the fact that Froude number tends to zero. Comparisons of the stability domains obtained without the rigid-lid assumption (i.e., Froude number ≠ 0) with those obtained with the rigid-lid assumption (i.e., Froude number = 0) show that the rigid-lid assumption works well for weak shear flows and/or small Froude numbers.
Fields of Study & Subjects
Hydraulic flow and structures
Fluid Dynamics and Turbulent Flows
Hydrology and Sediment Transport Processes
Publication details
- Journal / source
- CRC Press eBooks
- Pages
- 525–530
- Publication date
- 12 February 2026
- Language
- EN
- Document type
- Book chapter