sphere_drag.m

function [Cd_out] = sphere_drag(Re_in,spline_type)
    % interpolation for drag coeff based upon Reynolds number
    % output is
    % Cd: drag coeff
    % input is
    % Re_in: Reynolds number
    % and
    % spline_type: 'linear', 'cubic', or 'spline'/'pchip'

    %function [Cd_out]=sphere_drag(Re_in,spline_type)
    data = [2	0.52
    5.8	0.52
    16.8	0.52
    27.2	0.5
    29.9	0.49
    33.9	0.44
    36.3	0.18
    40	0.074
    46	0.067
    60	0.08
    100	0.12
    200	0.16
    400	0.19];

    Cd_out = interp1(data(:,1),data(:,2),Re_in,spline_type);
end