What is the range of the coefficients of hydrodynamic resistances for the rectangular edges at inlet?

In the context of fluid dynamics, particularly when considering flow past bodies such as dams, sluices, or channels, the coefficients of hydrodynamic resistances for rectangular edges at inlet (often related to the loss coefficients) can vary significantly. These coefficients are crucial in determining the head loss due to the shape and size of the inlet, among other factors.

The coefficient of hydrodynamic resistance, often denoted as (K), for rectangular inlets or edges, is influenced by the aspect ratio of the inlet (height to width ratio), the Reynolds number (which indicates whether the flow is laminar or turbulent), the edge geometry (sharp, rounded, beveled), and other specific conditions of the flow (like submergence).

Generally, for sharp-edged rectangular inlets, the range of (K) can be broad. In practice, (K) could range from 0.5 to about 1.5 for typical conditions, assuming laminar to turbulent transitions and variations in edge geometry. For a sharp-edged entrance without any modifications, the value often used for engineering calculations is around 0.5 to 0.6. This value assumes a somewhat idealized condition with full contraction of the jet entering the inlet. If the edges are rounded or if the flow conditions are otherwise optimized to minimize losses, (K) might be lower, even approaching values as small as 0.1 under highly optimized conditions.

Remember, these are indicative values, and specific situations will require detailed