# Solve ode23s in a for loop

3 Ansichten (letzte 30 Tage)
WANYI ZHANG am 19 Mai 2020
Kommentiert: WANYI ZHANG am 20 Mai 2020
I want to solve ode23s in a for loop, it solves eventually.
But takes very long time to solve it, can anyone tell me how can I reduce the
time to solve it. The main reason I am using this for loop is that my two of "CS_state"
is changing variables, and my dm_down is also dependent "CS_state"
Below is the code.
Thank you
%%
clc
clear
close all
%% Define global variable(Temperature in Kelvin)
global Kel
Kel = 273.15;
%% Include directories
%% HXsingle_params parameters
condenser_params.H = 138.3627; % Heat transfer coefficient[kWm^-2K^-1]
condenser_params.V = 0.8e-3; % Volume of the heat exhanger [m^3]
expansion_params.A_up = 0.1e-4; % Upstream cross-sectional area of the orifice [m^2]
expansion_params.A_down = 0.0046e-4; % Downstream cross-sectional area of the orifice [m^2]
V = 0.8e-3;
% Create HXsingle_params structure
HX_params.condenser_params=condenser_params;
HX_params.expansion_params=expansion_params;
%% Inputs
T_ext = 35 + Kel;
h_in = 4.571e5;
dm_in = 0.018;
P_out = 0.9e6;
%% Initial condition
Scon=177.1135;
m=0.1178;
CSmacro_state = [Scon;V;m];
v=V/m;
D=1/v;
% s=Scon/m;
CS_state = [Scon;V;m];
% Initial HX_state
x0=[Scon;m];
t=(0:0.01:10);
CS_h_out = zeros(length(t),1);
CS_P_out = zeros(length(t),1);
dm_down = zeros(length(t),1);
for i=1:length(t)
[~,CS_h_out(i),CS_P_out(i),~,~] = CSmacro_output(CS_state,"R410A");
[dm_down(i),~,~] = orifice(CS_h_out(i),CS_P_out(i),P_out,"R410A",expansion_params);
%% Link solver to system equations
ode_wrap = @(t,x) HXmacro_deriv(x,h_in,dm_in,dm_down(i),T_ext,"R410A",HX_params);
% run simulation
opts=odeset('RelTol',1e-6);
[t,x] = ode23s(ode_wrap,t,x0,opts);
CS_state = [x(i,1);V;x(i,2)];
% x0=x;
##### 3 Kommentare2 ältere Kommentare anzeigen2 ältere Kommentare ausblenden
WANYI ZHANG am 20 Mai 2020
And they are returning values, as my "CSmacro_output" function take varible CS_state, and whick
returns outputs CS_h_out and CS_P_out.

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