28、质量传递相关计算与分析

质量传递相关计算与分析

1 质量传递基础与代码实现

1.1 直径与浓度随时间变化的模拟

在质量传递的研究中，我们可以通过代码模拟直径和浓度随时间的变化。以下是相关代码：

fd(4) = pi*(Sa - x(4))*sum0/V - x(4)/tau;
fd(5) = pi*(Sd - x(5))*sum1/V - x(4)/tau;
dxdt = [fd(1) fd(2) fd(3) fd(4) fd(5)]';
end

% usedrugf.m
x10 = 0.5; x20 = 0.4; x30 = 0.35; x40 = 0; x50 = 0;
V = 1200; tau = 240; Sa = 1; Sd = 0.4; rho = 1414.7;
tspan = [0 150]; x0 = [x10 x20 x30 x40 x50];
[t x] = ode45(@drugf,tspan,x0,[],V,rho,tau,Sa,Sd);
D1 = x(:,1); D2 = x(:,2); D3 = x(:,3); Cas = x(:,4); Cds = x(:,5);
figure(1)
plot(t,D1,t,D2,':',t,D3,'.-'), xlabel('t(min)'), ylabel('D(cm)')
legend('D_1','D_2','D_3'), axis tight
figure(2)
plot(t,Cas,t,Cds,':'), xlabel('t(min)'), ylabel('C(mg/cm^3)')
axis tight, legend('C_{AS}','C_{DS}','