Matlab function of design equation for reactor 2

function V = steadystate_cstr_volumeR2(f,S,P)
%calculates volume of CSTR in steady state -> design equation
% f = flow
% S = substrate concentration
% P = product concentration that will leave the reactor
% we assume that the inlet water does not contain any product

kcat = 480; %[1/min]  Nir
kM = 0.053; % [mM] Nir
E = 8.457e-4; % estimation that cells take up 40% of the volume 1000 enz/cell

V = f*P/(((kcat*E*S)/(kM+S))*0.4);