functionK_conicalDiffuser
Gradual Expansion | Conical diffuser (small -> large area) | Local + friction loss
Extends from TRANSFORM.Icons.Function (Icon for functions).
Information
Resistance coefficient K for a gradual expansion (conical diffuser) per Rennels & Hudson (2012),
referenced to the velocity head in the smaller (inlet) cross-section, i.e. used as
dp = K*m_flow^2/(2*rho*min(A)^2).
The input angle is the total included cone (divergence) angle. The correlation is piecewise in
this angle and the diameter ratio beta = d_small/d_large; the pieces are constructed to be continuous
in value across the 20°/60° breakpoints and across beta = 0.5. At angle = 180°
the correlation reduces to the Borda-Carnot sudden-expansion limit K = (1 - beta^2)^2.
References
Rennels, D. C. & Hudson, H. M. Pipe Flow: A Practical and Comprehensive Guide. John Wiley & Sons (2012).
Inputs
| Type | Name | Default | Description |
|---|---|---|---|
| SI.Area[2] | crossAreas | {0.25, 1.0} | Cross-sectional areas (order does not matter) |
| SI.ReynoldsNumber | Re | Reynolds number (referenced to the smaller section) | |
| SI.Angle | angle | Total included cone (divergence) angle | |
| SI.Length | roughness | 0 | Average height of surface asperities |
| SI.ReynoldsNumber | Re_lam | 2300 | Laminar transition Reynolds number |
| SI.ReynoldsNumber | Re_turb | 4000 | Turbulent transition Reynolds number |
Outputs
| Type | Name | Default | Description |
|---|---|---|---|
| Units.NonDim | K | Resistance coefficient |