求助!!!!!!!!!!!!!!!!!!!!!!!!!
function cxsj()D=input('缸径D=');
S=input('汽缸行程S=');
n=input('转速=');
epsilon=input('压缩比=');
Ze=input('进气门个数=');
Za=input('排气门个数=');
Po=input('大气压力=');
To=input('大气温度=');
L=input('连杆长度=');
r=input('曲柄半径=');
for phi=0:1:720
if phi<180
Ma = S.*pi.*(D/2)^2.*28.97; %空气质量
vf=S.*pi.*D^2./4
Va = pi^2.*D^2.*S./(8.*180).*(sin(pi.*phi./180)+r./(2.*L).*sin(pi.*2.*phi./180)./(1-(r./L*sin(pi.*phi./180)^0.5))); %汽缸容积变化率
[x,y] = ode45(@xxx,[0 180],1);
plot(x,vf-y)
grid
end
end
% dV/dphi的表达式
function Y=xxx(x,y)
global D S L r
Y=pi^2.*D^2.*S./(8.*180).*(sin(pi.*x./180)+r./(2.*L).*sin(pi.*2.*x./180)./(1-(r./L*sin(pi.*x./180)^0.5)));
运行后出现??? Error using ==> funfun\private\odearguments
Solving XXX requires an initial condition vector of length 0.
Error in ==> ode45 at 173
[neq, tspan, ntspan, next, t0, tfinal, tdir, y0, f0, odeArgs, ...
Error in ==> Untitled8 at 19
[x,y] = ode45(@xxx,[0 180],1);
到底是怎么回事啊???[tk14]
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