汽车理论课后习题13.pdf

解：1)clear all f=0.013;G=38800;Ff=G*f;CdA=2.77;ul=0:1:120;Fw=CdA.*u 1 .A2/21.15;F=Ff+Fw;Ig=5.562.769 1.644 1.000 0.793;k=l:5;ngk=600 600 600 600 600;ngm=4000 4000 4000 4000 4000;r=0.367;I0=5.83;eta=0.85;ugk=0.377*r*ngk(k)./(Ig(k).*I0);ukm=0.377.*r.*ngm(k)./(Ig(k).*I0);for k=l:5u=ugk(k):ukm(k);n=Ig(k)*I0.*u./r/0.377;Tq=-19.313+295.27*n/1000-165.44*(n/1000).A2+40.874*(n/1000).A3-3.8445*(n/1000).A4;Ft=Tq.*I g(k)*I0*eta/r;plot(u,Ft,ul,F)hold on,grid onend2）最高车速求解程序:n,u=solve(,n=u*0.793*5.83/(0.377*0.367),(-19.3I3+295.27*(n/1000)-165.44*(n/1000)A2+40.874*(n/1000)八 33.8445*(n/1000)八 4)*0.793*5.83*0.85/0.367(2.77*u 八 2/21.15+3880*10*0.013)3299.9224534468163066899978278864264.136893381715449564714110612663533.8761660967238474546442908623+2707.8751259314497120563837339829*13533.8761660967238474546442908623-2707.8751259314497120563837339829*iu=98.7573451959465341846909621859647.9048701073070256438355939579073105.75891807712350450878660177051+81.039043290184796798403093329529*i105.75891807712350450878660177051-81.039043290184796798403093329529*1分析：u 的后三个解明显不符合题意，所以最高车速是98.757km/h求最大爬坡度和最大附着系数1=0.218;Iwl=1.798;Iw2=3.598;L=3.2;m=3880;r=0.367;eta=0.85;Cd=2.77;f=0.013;i0=5.83;a=1.947;hg=0.9;g=10;ig=5.56;2.769;1.644;1.00;0.793;fo r i=l:5th(i)=l+(Iwl+Iw2)/(m*rA2)+(I*i0A2+(ig(i)A2*eta)/(m*rA2);end fb r i=l:5ual(i,l)=(600*0.377*r)/(ig(i)*i0);ual(i,2)=(4000*0.377*r)/(ig(i)*i0);endua=ual(1,1):.O l:ual(l,2);x,y=size(ua);fb r i=l:yn=ua(i)*ig(l)*i0/(0.377*r);Tq=-19.313+295.27*(n/1000)-165.44*(n/1000)A2+40.874*(n/1000)A3-3.8445*(n/1000)A4;Ft(i)=Tq*ig(l)*iO*eta/r;Fw(i)=Cd*ua(i)A2/21.15;Fc(i)=Ft(i)-Fw(i)endplot(ua,Ft/1000,:,ua,Fc/1000，,ua,Fw/1000,)D=max(Fc)/m/g;af=asin(D-f*sqrt(l+fA2-DA2)/(l+fA2);i=tan(af)；q=i；cf2=q/(a/L+q*hg/L);i0.3448 cf2cf2=0.48883)clcclear1=0.218;Iwl=1.798;Iw2=3.598;L=3.2;m=3880;r=0.367;eta=0.85;Cd=2.77;f=0.013;i0=5.83;a=1.947;hg=0.9;g=10;ig=5.56;2.769;1.644;1.00;0.793;umax=96;for i=l:5th(i)=l+(Iw l+Iw2)/(m*rA2)+(I*iOA2+(ig(i)A2*eta)/(m*rA2);endfori=l:5ual(i,l)=(600*0.377*r)/(ig(i)*i0);if(4000*0.377*r)/(ig(i)*i0)umaxual(i,2)=(4000*0.377*r)/(ig(i)*i0);elseual(i,2)=umax;endendfor j=l:5ua=ual(j,1):ual(j,2);x,y=size(ua);for i=l:yn=ua(i)*ig(j)*i0/(0.377*r);Tq=-19.313+295.27*(n/1000)-165.44*(n/1000)A2+40.874*(n/1000)A3-3.8445*(n/1000)A4;Ft=Tq*ig(j)*iO*eta/r;Fz=Cd*ua(i)A2/21.15+m*g*f;a(i)=(th(j)*m)/(Ft-Fz);endplot(ua,a,-r)hold onend clcclear%定义个变量值：1=0.218;Iwl=1.798;Iw2=3.598;L=3.2;m=3880;r=0.367;eta=0.85;Cd=2.77;f=0.013;i0=5.83;a=1.947;hg=0.9;g=10;ig=5.56;2.769;1.644;1.00;0.793;%求出各档所对应加速质量系数fbri=l:5th(i)=l+(Iwl+Iw2)/(m*rA2)+(I*iOA2+(ig(i)A2*eta)/(m*rA2);endumax=99;%求出各档在最大车速范围内稳定转速所对应的速度for i=l:5ual(i,l)=(600*0.377*r)/(ig *i0);if(4000*0.377*r)/(ig(i)*i0)umaxual(i,2)=(4000*0.377*r)/(ig(i)*i0);elseual(i,2)=umax;endend%从二档到五档按照A 方法选取合适加速度for u=l:98if(uual(2,l)a(u)=0else if(u=ual(2,2)%当在二档u a内的加速度倒数n=u*ig(2)*i0/(0.377*r);Tq=-19.313+295.27*(n/1000)-165.44*(n/1000)A2+40.874*(n/1000)A3-3.8445*(n/1000)A4;Ft=Tq*ig(2)*iO*eta/r;Fz=Cd*u 八 2/21.15+m*g*f;a(u)=(th(2)*m)/(Ft-Fz);else if(u=ual(3,2)%在二档最大速度到三档最大速度内加速度倒数n=u*ig(3)*i0/(0.377*r);Tq=-19.313+295.27*(n/l 000)-165.44*(n/l 000)八 2+40.874*(n/1000)A3-3.8445*(n/1000)A4;Ft=Tq*ig(3)*i0*eta/r;Fz=Cd*uA2/21.15+m*g*f;a(u)=(th(3)*m)/(Ft-Fz);else if(u=ual(4,2)%在三档最大速度到四档最大速度内加速度倒数n=u*ig(4)*i0/(0.377*r);Tq=-19.313+295.27*(n/1000)-165.44*(n/1000)A2+40.874*(n/1000)A3-3.8445*(n/1000)A4;Ft=Tq*ig(4)*iO*eta/r;Fz=Cd*uA2/21.15+m*g*f;a(u)=(th(4)*m)/(Ft-Fz);else if(u=ual(5,2)%在四档最大速度到五档最大速度内加速度倒数n=u*ig(5)*i0/(0.377*r);Tq=-19.313+295.27*(n/1000)-165.44*(n/1000)A2+40.874*(n/1000)A3-3.8445*(n/1000)A4;Ft=Tq*ig(5)*i0*eta/r;Fz=Cd*uA2/21.15+m*g*f;a(u)=(th(5)*m)/(Ft-Fz);endendendendendendux=l:ual(2,l);%给低速无意义阶段的速度赋予5km/h时同样的加速度x,y=size(u x);for i=l:ya(i)=a(y+l)endt=0;u=l:9 8;for i=1:9 8t=t+l/3.6*a;图解积分法求解时间ts(i)=t;endplot(ts,u)title(速度时间图,)ylabel(,u a(km/h)x labeK tC s)tex t(3 3,7 0,leftarrow 7 0 k m/h 加速时间)Q Figure 2口 回File Edit View Insert Tools Desktop Window Help 玉D d d *|O 0小 国 国速度时间图100(WEX)en60440120100180t(s)204060ts(7 0)ans=2 7.4 8 3 0。