Contraction K Fittings
Contraction K fittings model the head loss that occurs when flow contracts from a larger cross-sectional area to a smaller one. The associated loss coefficient depends strongly on the included angle of the contraction (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 contraction 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 contraction for the specific circumstances.
The Contraction K library includes a variety of standard contraction configurations. For each fitting, the software defines the dimensional information and angle, enabling the correct formula to be applied automatically. When a Contraction 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 > Contraction K for the formulas and further information.
