.TRANSFORM.Fluid.ClosureRelations.PressureLoss.Functions.Diffusers.K_conicalConfuser

Information

Resistance coefficient K for a gradual contraction (conical confuser / nozzle) per Rennels & Hudson (2012), referenced to the velocity head in the smaller (outlet) cross-section, i.e. used as dp = K*m_flow^2/(2*rho*min(A)^2).

The input angle is the total included cone (convergence) angle. The loss is the sum of a friction term and a convective term that grows with the convergence parameter lambda.

References

Rennels, D. C. & Hudson, H. M. Pipe Flow: A Practical and Comprehensive Guide. John Wiley & Sons (2012).

Interface

function K_conicalConfuser
  extends TRANSFORM.Icons.Function;
  input SI.Area crossAreas[2] = {1.0, 0.25} "Cross-sectional areas (order does not matter)";
  input SI.ReynoldsNumber Re "Reynolds number (referenced to the smaller section)";
  input SI.Angle angle "Total included cone (convergence) angle";
  input SI.Length roughness = 0 "Average height of surface asperities";
  input SI.ReynoldsNumber Re_lam = 2300 "Laminar transition Reynolds number";
  input SI.ReynoldsNumber Re_turb = 4000 "Turbulent transition Reynolds number";
  output Units.NonDim K "Resistance coefficient";
end K_conicalConfuser;