Template Function es::lewkowicz_speed

• Defined in File velocity.h

Function Documentation

template <typename T_z, typename T_param>
T_z es::lewkowicz_speed(T_z const &z, T_param const &pi_coles, T_param const &kappa, T_param const &u_inf, T_param const &shear_ratio, T_param const &delta_c)

Compute Lewkowicz (1982) velocity profile.

Used by Perry and Marusic 1995 (from eqs 2 and 7).

Templated so that it can be called with active scalars (allows use of autodiff), doubles/floats, Eigen::Arrays (directly) or Eigen::VectorXds (via template specialisation) of z values.

Translated from MATLAB:

function [f] = getf(eta, Pi, kappa, S)
    f = (-1/kappa)*log(eta) + (Pi/kappa)*colesWake(1,Pi)*ones(size(eta)) - (Pi/kappa)*colesWake(eta,Pi);
    f(isinf(f)) = S;
end

Parameters

• z: height in m (or Nondimensional heights (eta = z/delta_c) where delta_c = 1.0)
• pi_coles: The coles wake parameter Pi
• kappa: von Karman constant
• u_inf: Speed of flow at z = delta (m/s)
• shear_ratio: Shear / skin friction velocity ratio (shear_ratio = u_inf / u_tau)
• delta_c: Boundary layer thickness in m, used to normalise z. Defaults to 1.0.