Contents

clear;
clc;

Setup

%=========inputs=========
%{
o/f ratio
m dot
k coefficient
propellant densities                depends on temperature usually, maybe parameterize
pressure drop across injector
number of holes
%}

%=========equations=========
%{
area_injection=m_dot*sqrt(2.238*k/(rou*deltaP));

diameter_hole(N)=((3.627*K*(m_dot^2))/(rou*delatP*(N^2)))^.25

minimum manifold cross sectional area is 4 times area of injection - huzel&huang and Cian ig
%}

Inputs

ox_m_dot=1.5;         %[kg/s]
fuel_m_dot=.5;        %[kg/s]
K=1.7;                %
rou_ox=991.5;         %[kg/m^3]
rou_fuel=785.027;     %[kg/m^3]
deltaP_ox=175;        %[PSI]
deltaP_fuel=175;      %[PSI]

for loop to parse through range of hole sizes

use when you want dgaf about amount of pairs and want to use avaliable drill bits

% for i=5:8
%
% N=i;
%
% d_orifice_ox=d_orifice_func(ox_m_dot,K,rou_ox,deltaP_ox,N);
% d_orifice_fuel=d_orifice_func(fuel_m_dot,K,rou_fuel,deltaP_fuel,N);
%
% disp("N is "+N);
% disp(d_orifice_ox);
% disp(d_orifice_fuel);
%
% end

functions

function [A_injection] = A_injection_func(m_dot,K,rou,deltaP)
% conversions
m_dot=m_dot*2.20462;
rou=rou*0.062428;
%equation
A_injection=m_dot*sqrt((2.238*K)/(rou*deltaP));
end

A_injection_ox=A_injection_func(ox_m_dot,K,rou_ox,deltaP_ox);
A_injection_fuel=A_injection_func(fuel_m_dot,K,rou_fuel,deltaP_fuel);

disp("====================OUTPUT====================")
disp("Area of Injection for Ox is "+A_injection_ox+" [in^2]");
disp("Area of Injection for Fuel is "+A_injection_fuel+" [in^2]");


function [d_orifice] = d_orifice_func(m_dot,K,rou,deltaP,N)
% conversions
m_dot=m_dot*2.20462;
rou=rou*0.062428;
%equation
d_orifice=((3.627*K*(m_dot)^2)/(rou*deltaP*(N^2)))^.25;
end

%============
N=8;
%============

d_orifice_ox=d_orifice_func(ox_m_dot,K,rou_ox,deltaP_ox,N);
d_orifice_fuel=d_orifice_func(fuel_m_dot,K,rou_fuel,deltaP_fuel,N);
disp("N is "+N);
disp(d_orifice_ox)
disp(d_orifice_fuel)

%============
N=10;
%============

d_orifice_ox=d_orifice_func(ox_m_dot,K,rou_ox,deltaP_ox,N);
d_orifice_fuel=d_orifice_func(fuel_m_dot,K,rou_fuel,deltaP_fuel,N);
disp("N is "+N);
    disp(d_orifice_ox);
disp(d_orifice_fuel);

====================OUTPUT====================
Area of Injection for Ox is 0.061976 [in^2]
Area of Injection for Fuel is 0.023217 [in^2]
N is 8
    0.0993

    0.0608

N is 10
    0.0888

    0.0544

Published with MATLAB® R2024b