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1、汽车理论作业姓名：陈洪平学号：021100701班级：车辆一班1.3解：(1)绘制驱动力与行驶阻力平衡图的Matlab程序：i0=5.83;r=0.367;nt=0.85;m=3880;g=9.8;f=0.013;CdA=2.27;ig=6.093.091.71 1; n=600:1:4000; ua=0:1:120; ua1=0.377*r*n./ig(1)./i0; ua2=0.377*r*n./ig(2)./i0; ua3=0.377*r*n./ig(3)./i0; ua4=0.377*r*n./ig(4)./i0; N=n./1000; Tq=-19.313+295.27.*N-165
2、.44.*NA2+40.874.*NA3-3.8445*NA4; Ft1=Tq.*ig(1).*i0.*nt./r; Ft2=Tq.*ig(2).*i0.*nt./r; Ft3=Tq.*ig(3).*i0.*nt./r; Ft4=Tq.*ig(4).*i0.*nt./r; F=m*g*f+CdA/21.15*ua.A2; plot(ua1,Ft1,ua2,Ft2,ua3,Ft3,ua4,Ft4,ua,F); set(gca, XTick,0 40 80 120 ); set(gca,YTick,0 2000 4000 6000 8000 10000 12000 14000 16000);gte
3、xt(FtT),gtext(Ft2),gtext(Ft3),gtext(Ft4),gtext(Ff+Fw); title( 汽车驱动力-行驶阻力平衡图); xlabel(Ua/(km/h); ylabel(Ft/N);Matlab运行结果:14000汽车驱动力行驶阻力平衡图Uam/h) 由驱动力与行驶阻力平衡图可得 见E=94.93km/h求汽车最大爬坡度是可根据公式0gM = orcsinuf - F1R ifnaii+f3工+严再根据tanamax =蹴皿换算成最大爬坡度。汽车在最大爬坡度时，具空气阻力、加速阻力、滚动阻力可忽略不计，所以附着率可简化为:求最大爬坡度及其相应附着率的 Mat
4、lab程序：i0=5.83;r=0.367;nt=0.85;m=3880;g=9.8;f=0.013;CdA=2.27;L=3.2;a=1.947;h g=0.9;ig=6.09 3.09 1.71 1;n=(600:1:4000);ua1=0.377*r*n./ig(1)./i0;N=n./1000;Tq=-19.313+295.27.*N-165.44.*NA2+40.874.*NA3-3.8445*NA4;Ft1=Tq.*ig(1).*i0.*nt./r;D1=(Ft1-CdA/21.15*ua1.A2)/(m*g);Dmax=max(D1);amax=asin(Dmax-f.*sqrt
5、(1-Dmax.A2+f.A2)/(1+f.A2);imax=tan(amax);e=imax/(a/L+hg*imax/L);disp( 汽车最大爬坡度imax=);disp(imax);disp( 相应的附着率=);disp(e);Matlab 运行结果：汽车最大爬坡度imax=0.3934相应的附着率=0.5471( 3) 绘制汽车行驶加速度倒数曲线曲线的 Matlab 程序：m=3880;r=0.367;nt=0.85;f=0.013;CdA=2.77;i0=5.83;If=0.218;Iw1=1.798;Iw2=3.598; ig=6.09 3.09 1.71 1;g=9.8;n=6
6、00:1:4000;ua=0:1:120;O1=1+(Iw1+Iw2+If*ig(1)A2*i0A2*nt)/(m*rA2);O2=1+(Iw1+Iw2+If*ig(2)A2*i0A2*nt)/(m*rA2);O3=1+(Iw1+Iw2+If*ig(3)A2*i0A2*nt)/(m*r.A2)；O4=1+(Iw1+Iw2+If*ig(4).A2*i0A2*nt)/(m*r.A2)；ua1=0.377.*r.*n./ig(1)./i0;ua2=0.377.*r.*n./ig(2)./i0;ua3=0.377.*r.*n./ig(3)./i0;ua4=0.377.*r.*n./ig(4)./i0;
7、N=n./1000;Tq=-19.313+295.27.*N-165.44.*N.A2+40.874.*N.A3-3.8445.*N.A4;Ft1=Tq.*ig(1).*i0.*nt./r;Ft2=Tq.*ig(2).*i0.*nt./r;Ft3=Tq.*ig(3).*i0.*nt./r;Ft4=Tq.*ig(4).*i0.*nt./r;Fw1=CdA*ua1.A2/21.15;Fw2=CdA*ua2.A2/21.15;Fw3=CdA*ua3.A2/21.15;Fw4=CdA*ua4.A2/21.15;D1=(Ft1-Fw1)/(m*g);D2=(Ft2-Fw2)/(m*g);D3=(Ft3-
8、Fw3)/(m*g);D4=(Ft4-Fw4)/(m*g);ad1=O1./(g*(D1-f);ad2=O1./(g*(D2-f);ad3=O1./(g*(D3-f);ad4=O1./(g*(D4-f);plot(ua1,ad1,ua2,ad2,ua3,ad3,ua4,ad4);axis(0 100 0 10);title( 汽车的加速度倒数曲线);xlabel(ua);ylabel(1/a);gtext(1/a1);gtext(1/a2);gtext(1/a3);gtext(1/a4);Matlab运行结果：汽车的加速度倒数曲线U3求2档起步加速行驶至70km/h的加速时间的Matlab程序
9、：m1=2000;m2=1800;m=3880;r=0.367;nt=0.85;f=0.013;CdA=2.77;i0=5.83;If=0.218;Iw1=1.798;Iw2=3.598;Ig=6.09 3.09 1.71 1;g=9.8;fo门=1:3401;for j=1:4;n(i)=i+599;ua(i,j)=0.377*r*n(i)./(Ig(j)*i0);O(j)=1+(Iw1+Iw2)/(m*rA2)+If*Ig(j)A2*i0A2*nt/(m*rA2);endenduamax=max(ua);uamin=min(ua);ua2=uamin(2):uamax(2);n=ua2*i
10、0*Ig(2)/(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;Ft2=Tq*i0*Ig(2)*nt/r;F2=m*g*f+CdA*ua2 A2/21.15;ad2=(Ft2-F2)./(O(2)*m);t2=trapz(ua2,1./ad2)/3.6;ua3=uamax(2):uamax(3);n3=ua3*i0*Ig(3)/(0.377*r);Tq3=-19.313+295.27*(n3/1000)-165.44*(n3/1000).A2+40.874*(n
11、3/1000).A3-3.8445*(n3/1000).A4;Ft3=Tq3*i0*Ig(3)*nt/r;F3=m*g*f+CdA*ua3.A2/21.15;ad3=(Ft3-F3)./(O(3)*m);t3=trapz(ua3,1./ad3)/3.6;ua4=uamax(3):70;n4=ua4*i0*Ig(4)/(nt*r);Tq4=-19.313+295.27*(n4/1000)-165.44*(n4/1000).A2+40.874*(n4/1000).A3-3.8445*(n4/1000).A4;Ft4=Tq4*5.83*Ig(4)*nt/r;F4=m*g*f+CdA*ua4.A2/2
12、1.15;ad4=(Ft4-F4)./(O(4)*m);t4=trapz(ua4,1./ad4)/3.6;t=t2+t3+t4Matlab 运行结果： t =27.6350。所以汽车2档起步加速行驶至 70km/h 的加速时间为 27.6350s2.7 解(1) 绘制汽车功率平衡图的 Matlab 程序：i0=5.83;r=0.367;nt=0.85;m=3880;g=9.8;f=0.013;CdA=2.27;ig=6.093.091.71 1;n=600:1:4000;ua=0:0.1:120;ua1=0.377.*r.*n./ig(1)./i0;ua2=0.377.*r.*n./ig(2)
13、./i0;ua3=0.377.*r.*n./ig(3)./i0;ua4=0.377.*r.*n./ig(4)./i0;N=n./1000;Tq=-19.313+295.27.*N-165.44.*N.A2+40.874.*N.A3-3.8445.*N.A4;Ff=m*g*f;Fw=CdA*ua.A2/21.15;Pf=Ff*ua/3600;Pw=Fw.*ua/3600;Pe0=(Pf+Pw)./nt;Pe1=Tq.*ig(1)*i0.*ua1./(3600*r);Pe2=Tq.*ig(2)*i0.*ua2./(3600*r);Pe3=Tq.*ig(3)*i0.*ua3./(3600*r);Pe
14、4=Tq.*ig(4)*i0.*ua4./(3600*r);Pe=max(Pe1);plot(ua1,Pe1,ua2,Pe2,ua3,Pe3,ua4,Pe4,ua,Pe0,ua,Pe);title(汽车功率平衡图);xlabel(ua/(km/h);ylabel(Pe/kw);gtext(1),gtext(2),gtext(3),gtext(4),gtext(Pf+Pw)/nt),gtext (Pe);Matlab运行结果：2040 E0 60 WO 120ua/(kin/h)汽车功率平衡图 00706n5040/WOJOLu d(2)绘制最高档与次高档的等速百公里油耗曲线的Matlab程序：
15、m=3880;g=9.8;r=0.367;nt=0.85;f=0.013;CdA=2.77;i0=5.83;pg=7.1;ig=6.09 3.09 1.71 1;n=600:1:4000;n0=815 1207 1614 2012 2603 3006 3403 3804;B00=1326.8 1354.7 1284.4 1122.9 1141.0 1051.2 1233.9 1129.7;B10=-416.46 -303.98 -189.75 -121.59 -98.893 -73.714 -84.478 -45.291;B20=72.379 36.657 14.524 7.0035 4.4763 2.8593 2.9788 0.71113;B30=-5.8629 -2.0553 -0.51184 -0
