clear ;
addpath(genpath('.'))

% Compression ratio & critic ratio
r =  18 ; % [-]
rc =  2 ; % [-]

% Units
MPa = 1e6 ;    % [Pa]
cm  = 1/100 ;  % [m]
g   = 1/1000 ; % [kg]
kJ  = 1000 ;   % [J]

% Ideal gas, air
gas.Rbar = 8.314 ;            % [J/(mol*K)]
gas.M    = 28.97 * g ;        % [kg/mol]
gas.R    = gas.Rbar / gas.M ; % [J/(kg*K)]

% States
state1.T  = 300 ;         % [K]
state1.p  = 0.1 * MPa ;   % [Pa]
state1.v  = getVariableFromStateEquation("v", state1, gas) ;
state1.vr = getValueFromTable("vr", "T", state1.T) ;      % [-]
state1.u  = getValueFromTable("u",  "T", state1.T) * kJ ; % [J/kg]

% 1-2 (isoentropic compression)
state2.v  = state1.v  / r ;
state2.vr = state1.vr / r ;
state2.T  = getValueFromTable("T", "vr", state2.vr) ; % [K]
state2.h  = getValueFromTable("h", "T",  state2.T) * kJ ;
state2.p  = getVariableFromStateEquation("p", state2, gas) ;

% 2-3 (p=const)
state3.v  = state2.v * rc ;
state3    = getStateAfterIsobaricProcess(state2, state3, gas) ;
state3.vr = getValueFromTable("vr", "T", state3.T) ;      % [-]
state3.h  = getValueFromTable("h",  "T", state3.T) * kJ ;

% 3-4 (isoentropic expansion)
state4.v  = state1.v ;
state4.vr = state3.vr * ( state4.v / state3.v ) ;
state4.T  = getValueFromTable("T", "vr", state4.vr) ; % [K]
state4.u  = getValueFromTable("u", "T",  state4.T) * kJ ;
state4.p  = getVariableFromStateEquation("p", state4, gas) ;

% Work per unit mass per cycle [J/kg]
qIn  = state3.h - state2.h ;
qOut = state4.u - state1.u ;
l    = qIn - qOut ;

% Thermal efficiency
eta = l / qIn 

% Mean effective pressure [Pa]
Dv = state1.v - state2.v ;
pme = l / Dv