汽車理論作業(yè)

1、最新可編輯word文檔汽車理論作業(yè)姓名：陳洪平學號：021100701班級：車輛一班3.091.3解：(1)繪制驅動力與行駛阻力平衡圖的Matlab程序：i0=5.83;r=0.367;nt=0.85;m=3880;g=9.8;f=0.013;CdA=2.27;ig=6.091.711;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-1

2、65.44.*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',04080120);set(gca,'YTick',0200040006000800010000120001400016000);gt

3、ext('FtT),gtext('Ft2'),gtext('Ft3'),gtext('Ft4'),gtext('Ff+Fw');title('汽車驅動力-行駛阻力平衡圖');xlabel('Ua/(km/h)');ylabel('Ft/N');Matlab運行結果：由驅動力與行駛阻力平衡圖可得4mM=94.93km/hImaxfJ1"ins+'m3=wcstn-3求汽車最大爬坡度是可根據(jù)公式1+/再根據(jù)的/皿=/換算成最大爬坡度。汽車在最大爬坡度時，具空氣阻

4、力、加速阻力、滾動阻力可忽略不計，所以附著Lmax率可簡化為：求最大爬坡度及其相應附著率的Matlab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;hg=0.9;ig=6.093.091.711;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.A

5、2)/(m*g);Dmax=max(D1);amax=asin(Dmax-f.*sqrt(1-Dmax.A2+f.A2)/(1+f.A2);imax=tan(amax);e=imax/(a/L+hg*imax/L);disp('汽車最大爬坡度imax=');disp(imax);disp('相應的附著率=');disp(e);Matlab運行結果：汽車最大爬坡度imax=0.3934相應的附著率=0.5471(3)繪制汽車行駛加速度倒數(shù)曲線曲線的Matlab程序：m=3880;r=0.367;nt=0.85;f=0.013;CdA=2.77;i0=5.83;If

6、=0.218;Iw1=1.798;Iw2=3.598;ig=6.093.091.711;g=9.8;n=600:1:4000;ua=0:1:120;O1=1+(Iw1+Iw2+If*ig(1).A2*i0.A2*nt)/(m*r.A2);O2=1+(Iw1+Iw2+If*ig(2).A2*i0.A2*nt)/(m*r.A2);O3=1+(Iw1+Iw2+If*ig(3).A2*i0.A2*nt)/(m*r.A2);O4=1+(Iw1+Iw2+If*ig(4).A2*i0.A2*nt)/(m*r.A2);ua1=0.377.*r.*n./ig(1)./i0;ua2=0.377.*r.*n./ig

7、(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-165.44.*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=C

8、dA*ua4.A2/21.15;D1=(Ft1-Fw1)/(m*g);D2=(Ft2-Fw2)/(m*g);D3=(Ft3-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(0100010);title('汽車的加速度倒數(shù)曲線);xlabel('ua');ylabel('1/a');gtext('1/a1

9、9;);gtext('1/a2');gtext('1/a3');gtext('1/a4');Matlab運行結果:汽車的加速度倒數(shù)曲線求2檔起步加速行駛至70km/h的加速時間的Matlab程序：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=6.093.091.711;g=9.8;fo門=1:3401;forj=1:4;n(i)=i+599;ua(i,j)=0.377*r*n(i)./(Ig(j)*i0

10、);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*i0*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

11、./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*(n3/1000).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+295.2

12、7*(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.A2/21.15;ad4=(Ft4-F4)./(O(4)*m);t4=trapz(ua4,1./ad4)/3.6;t=t2+t3+t4Matlab運行結果：t=27.6350。所以汽車2檔起步加速行駛至70km/h的加速時間為27.6350s2.7解(1)繪制汽車功率平衡圖的Matlab程序：i0=5.83;r=0.367;nt=0.85;m=3880;g=9.8;f=0

13、.013;CdA=2.27;ig=6.093.091.711;n=600:1:4000;ua=0:0.1:120;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-165.44.*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+

14、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);Pe4=Tq.*ig(4)*i0.*ua4./(3600*r);Pe=max(Pe1);plot(ua1,Pe1,ua2,Pe2,ua3,Pe3,ua4,Pe4,ua,Pe0,ua,Pe);title('汽車功率平衡圖');xlabel('ua/(km/h)');ylabel('Pe/kw');gtext('1'),gtext

15、(2),gtext('3'),gtext('4'),gtext('(Pf+Pw)/nt'),gtext('Pe');Matlab運行結果：0204060 BOu 消km/h)100120汽車功率平衡圖 8070605040200(2)繪制最高檔與次高檔的等速百公里油耗曲線的Matlab程序：m=3880;g=9.8;r=0.367;nt=0.85;f=0.013;CdA=2.77;i0=5.83;pg=7.1;ig=6.093.091.711;n=600:1:4000;n0=8151207161420122603300634033

16、804;B00=1326.81354.71284.41122.91141.01051.21233.91129.7;B10=-416.46-303.98-189.75-121.59-98.893-73.714-84.478-45.291;B20=72.37936.65714.5247.00354.47632.85932.97880.71113;B30=-5.8629-2.0553-0.51184-0.18517-0.091077-0.05138-0.047449-0.00075215;B40=0.177680.0430720.00681640.00185550.000689060.0003503

17、20.00028230-0.000038568;B0=spline(n0,B00,n);B1=spline(n0,B10,n);B2=spline(n0,B20,n);B3=spline(n0,B30,n);B4=spline(n0,B40,n);ua3=0.377*r*n/ig(3)/i0;ua4=0.377*r*n/ig(4)/i0;Ff=m*g*f;Fz3=Ff+CdA*(ua3A2)/21.15;Fz4=Ff+CdA*(ua4A2)/21.15;Pe3=Fz4.*ua3./(nt*3.6*1000);Pe4=Fz4.*ua4./(nt*3.6*1000);fori=1:1:3401b3(i)=B0(i)+B1(i)*Pe3(i)+B2(i)*Pe3(i).A2+B3(i)*Pe3(i).A3+B4(i)*Pe3(i).A4;b4(i)=B0(i)+B1(i)*Pe4(i)+B2(i)*Pe4(i).A2+B3(i)*Pe4(i).A3+B4(i)*Pe4(i).A4;endQ3=Pe3.*b3./(1.02.*ua3.*pg);Q4=Pe4.*b4./(1.02.*ua4.*pg);plo