MATLAB: Please tell the solution

enthalpy estimationgasifier

function h_t=t_enthalpy(T)
%%%% Vector containing the total enthalpy of each species at a specified
%%%% temperature
T_ref=298.15;
h_t=zeros(11,1);
%%% Order of the components [bms, water, char, o2, n2, steam,
%%% co2, h2, co, ch4, tars]
%Cp of the gases: [O2, N2, steam, CO2, H2, CO, CH4, tars]
%Form of the eq: Cp=A+Bt+Ct^2+Dt^3+E/t^2; t=T/1000
%Gases in this cp matrix and formation enthalpy vector: O2, N2, steam, CO2,
%H2, CO, CH4]
t=T/1000;
Cp=(29.659+6.137261*t-1.186521*t^2+0.095780*t^3-0.219663*t^-2+26.092+8.218801*t-1.976141*t^2+0.159274*t^3+0.044434*t^-2+30.092+6.832514*t+6.793435*t^2-2.53448*t^3+0*0.082139*t^-2+24.99735+55.18696*t-33.69137*t^2+7.948387*t^3-0.136638*t^-2+33.066178-11.363417*t+11.432816*t^2-2.772874*t^3-0.158558*t^-2+25.56759+6.096130*t+4.054656*t^2-2.671301*t^3+0.131021*t^-2-0.703029+108.4773*t-42.52157*t^2+5.862788*t^3+0.678565*t^-2); %[j/mol k]
hf=1000*[0; 0; -241.83; -393.51; 0; -110.53; -74.87]; %[j/mol]
%%% Calculation of the enthalpy for the gaseous components
t_ref=T_ref/1000;
h_t(1:10)=hf+(1000*(Cp(:,1)*(t-t_ref)+Cp(:,2)*((t^2-t_ref^2)/2)+Cp(:,3)*((t^3-t_ref^3)/3)+Cp(:,4)*((t^4-t_ref^4)/4)+Cp(:,5)*(1/t_ref-1/t)));
%%% Calculation for the biomass
w_bms=23.5020; %[g/mol]
h_t(1)=-89854.0977+(w_bms/1000)*(3.86*(T^2-T_ref^2)/2+103.1*(T-T_ref));
%%% Calculation for water
h_t(2)=-285800+(18/1000)*4180*(T-T_ref);
%%% Calculation for char
h_t(3)=0+(12/1000)*(0.36*(T^2-T_ref^2)/2+1390*(T-T_ref));
%%% Calculation for tars
h_t(11)=1000*82.927+(88.627*(T-T_ref)+0.12074*(T^2-T_ref^2)/2-0.12735e-4*(T^3-T_ref^3)/3-0.36688e7*(1/T_ref-1/T));
end
%% In this code it is showing "Index in position 2 exceeds array bounds (must not exceed 1)".

Best Answer

If ‘T’ is a scalar, note that ‘Cp’ is also a scalar, so by definition it is a (1x1) array. Referring to it with any dimension greater than 1 in any dimension will throw a similar error.
If ‘T’ is a vector, the problem becomes one of requiring element-wise operations in the ‘Cp’ calculation (and perhaps others).
See: Array vs. Matrix Operations for help with that.
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