Expansion K Fittings
Expansion K fittings model the head loss that occurs when flow expands from a smaller cross-sectional area to a larger one. The associated loss coefficient depends strongly on the included angle of the expansion (θ) and the Reynolds Number, as both factors influence the extent of flow separation and energy dissipation through the transition.
To provide accurate results across a broad range of operating conditions, Pipe Flow Expert uses formulas that adapt to both the expansion geometry and the flow conditions. Different relationships are applied depending on the value of the angle (θ) and the calculated Reynolds number, ensuring that the resulting K value reflects the expected behaviour of the expansion for the specific circumstances.
The Expansion K library includes a variety of standard expansion configurations. For each fitting, the software defines the dimensional information and angle, enabling the correct formula to be applied automatically. When an Expansion K Fittings is added to a pipe, Pipe Flow Expert evaluates the flow conditions and determines the appropriate K value dynamically.
See Section: Calculation Theory and Method of Solution > Expansion K for the formulas and further information.
