import numpy as np
import math
#format long e;
#pick the y+
y_plus = 1;
#constants
rho = 1.225;
mu = 1.789e-05;
nu = mu/rho;
#define Reynolds number
Re = 6 * 1.0e06
#define the reference length in meters
L = 1 ;
#compute coefficient of friction
Cf = 0.074 * math.pow(Re, (-1.0/5.0));
#compute the reference velocity (Average)
ua = (Re*nu)/(L);
#compute the friction velocity
V_f = ua * math.sqrt(Cf/2.0);
#compute the wall unit
y_t = nu / V_f;
#compute the first spacing wall specific to the wanted y+
y = (y_plus*L)/((math.sqrt(0.037))*math.pow(Re,0.9))
print y