Pipe diameter calculation for specified pressure drop      |POLVER05_3
f(D) = -dp/rho+2*fF*v*v*L/D    #
f(fF) = if (Re<2100) then (fF-16/Re) else (fF-1/(4*log(Re*(fF)^(1/2))-0.4)^2)  #
dp=103000    #
L=100    #
T=25+273.15    #
Q=0.0025    #
pi=3.1416    #
rho=46.048+T*(9.418+T*(-0.0329+T*(4.882e-5-T*2.895e-8)))    #
vis=exp(-10.547+541.69/(T-144.53))    #
v=Q/(pi*D^2/4)    #
kvis=vis/rho    #
Re=v*D/kvis    #
D(0)=0.04
fF(0)=.001