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

The coefficients of hydrodynamic resistances for rounded edges at inlets, often specified in terms of loss coefficients or resistance coefficients, depend on various factors such as the shape of the inlet, the degree of rounding, and flow conditions. For rounded inlets, these coefficients are generally lower than for sharp-edged inlets due to the smoother flow transition.

In fluid dynamics, particularly when dealing with incompressible flow situations like water flowing through pipes or openings, the range of these coefficients can vary widely based on the specifics mentioned above. For rounded edges at inlets, the loss coefficient ((K)) values typically range from approximately 0.04 to 0.5 under common conditions. This range assumes a moderate degree of rounding and typical flow velocities. For very well-rounded inlets, the coefficient can be at the lower end of this range or even slightly below, reflecting the reduced resistance and smoother acceleration of the fluid into the pipe or conduit.

It’s important to note that the exact value within this range for a specific situation depends on the Reynolds number, the relative roughness of the rounding, and the geometric proportions of the rounded edge compared to the diameter of the inlet. Computational fluid dynamics (CFD) simulations or specific empirical correlations based on experimental data are often used to determine more precise values for a particular design or application.