汽车理论课后习题1..doc

解：1） clear all f=0.013; G=38800;Ff=G*f; CdA=2.77;u1=0:1:120; Fw=CdA.*u1.2/21.15;F=Ff+Fw;Ig=5.56 2.769 1.644 1.000 0.793;k=1:5; 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=1:5u=ugk(k):ukm(k);n=Ig(k)*I0.*u./r/0.377; Tq=-19.313+295.27*n/1000-165.44*(n/1000).2+40.874*(n/1000).3-3.8445*(n/1000).4;Ft=Tq.*Ig(k)*I0*eta/r;plot(u,Ft,u1,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),(-19.313+295.27*(n/1000)-165.44*(n/1000)2+40.874*(n/1000)3-3.8445*(n/1000)4)*0.793*5.83*0.85/0.367-(2.77*u2/21.15+3880*10*0.013) n = 3299.9224534468163066899978278864 264.13689338171544956471411061266 3533.8761660967238474546442908623 + 2707.8751259314497120563837339829*i 3533.8761660967238474546442908623 - 2707.8751259314497120563837339829*i u = 98.757345195946534184690962185964 7.9048701073070256438355939579073 105.75891807712350450878660177051 + 81.039043290184796798403093329529*i 105.75891807712350450878660177051 - 81.039043290184796798403093329529*i 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I=0.218; Iw1=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;for i=1:5th(i)=1+(Iw1+Iw2)/(m*r2)+(I*i02+(ig(i)2*eta)/(m*r2);endfor i=1:5ual(i,1)=(600*0.377*r)/(ig(i)*i0);ual(i,2)=(4000*0.377*r)/(ig(i)*i0);endua=ual(1,1):.01:ual(1,2);x,y=size(ua);for i=1:yn=ua(i)*ig(1)*i0/(0.377*r);Tq=-19.313+295.27*(n/1000)-165.44*(n/1000)2+40.874*(n/1000)3-3.8445*(n/1000)4;Ft(i)=Tq*ig(1)*i0*eta/r; Fw(i)=Cd*ua(i)2/21.15;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(1+f2-D2)/(1+f2);i=tan(af);q=i;cf2=q/(a/L+q*hg/L); ii =0.3448 cf2cf2 = 0.48883） clcclearI=0.218; Iw1=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=1:5th(i)=1+(Iw1+Iw2)/(m*r2)+(I*i02+(ig(i)2*eta)/(m*r2);endfor i=1:5ual(i,1)=(600*0.377*r)/(ig(i)*i0);if (4000*0.377*r)/(ig(i)*i0) clcclear%定义个变量值：I=0.218; Iw1=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for i=1:5th(i)=1+(Iw1+Iw2)/(m*r2)+(I*i02+(ig(i)2*eta)/(m*r2);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=1:5ual(i,1)=(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;endend%从二档到五档按照A方法选取合适加速度for u=1:98if(uual(2,1)a(u)=0else if(u=ual(2,2) %当在二档ua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)2+40.874*(n/1000)3-3.8445*(n/1000)4;Ft=Tq*ig(2)*i0*eta/r;Fz=Cd*u2/21.15+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/1000)-165.44*(n/1000)2+40.874*(n/1000)3-3.8445*(n/1000)4;Ft=Tq*ig(3)*i0*eta/r;Fz=Cd*u2/21.15+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+29