给出matlab程序,其中R1 = 1.2e-3; R2 = 9.2e-3; Cin = 1.1e6/60; Cwall = 1.86e8/60; PN = 8000; qin = 20; qout = 0; u1 = diff(u); v1 = diff(v);
时间: 2023-08-04 19:08:19 浏览: 51
根据题目给出的参数和变量,可以编写如下的Matlab程序:
```
% 定义常数
R1 = 1.2e-3;
R2 = 9.2e-3;
Cin = 1.1e6/60;
Cwall = 1.86e8/60;
PN = 8000;
qin = 20;
qout = 0;
% 定义常微分方程
syms u v
eq1 = Cin*u == PN - (u - v)/R1;
eq2 = Cwall*v == (u - v)/R1 - (v - qout)/R2;
% 求解稳态解
u_steadystate = solve(eq1, u);
v_steadystate = solve(eq2, v);
% 输出稳态解
fprintf('u_steadystate = %f\n', double(u_steadystate));
fprintf('v_steadystate = %f\n', double(v_steadystate));
% 求解u和v对时间的导数
u1 = diff(u);
v1 = diff(v);
% 定义时间t和初值条件
tspan = [0 100];
y0 = [u_steadystate, v_steadystate];
% 定义ODE函数
odefun = @(t, y) [Cin*(PN - (y(1) - y(2))/R1) - qin; ...
Cwall*((y(1) - y(2))/R1 - (y(2) - qout)/R2)];
% 求解ODE方程
[t, y] = ode45(odefun, tspan, y0);
% 绘制u和v随时间变化的图像
figure;
plot(t, y(:, 1), 'r-', t, y(:, 2), 'b--', 'LineWidth', 2);
xlabel('Time (s)');
ylabel('Value');
legend('u', 'v');
title('u and v vs. Time');
```
该程序首先求解常微分方程的稳态解,然后定义ODE函数,使用ode45函数求解ODE方程,最后绘制u和v随时间变化的图像。