資源描述:
《汽車運(yùn)用工程綜合大作業(yè)》由會(huì)員上傳分享,免費(fèi)在線閱讀,更多相關(guān)內(nèi)容在行業(yè)資料-天天文庫(kù)。
1、汽運(yùn)大作業(yè)授課教師:許洪國(guó)班級(jí):441002學(xué)號(hào):44100221姓名:衡威威(一)汽車動(dòng)力性計(jì)算(1)繪制汽車驅(qū)動(dòng)力與行駛阻力平衡圖;;;其他參數(shù)已知;又以上條件可求出Ft,并畫(huà)出圖形。;參數(shù)均已知,可求出圖形。數(shù)據(jù)表格見(jiàn):《附表一》(2)求最高車速令Ft=Ff+Fw,得到方程使用MATLAB求解>>p=[0.000165,-0.042,4.16,-173.68,629.58]p=0.0002-0.04204.1600-173.6800629.5800>>px=poly2str(p,'x')px=0.000165x^4-0.042x^3+4.16x^2-173.
2、68x+629.58>>formatrat%>>r=roots(p)r=17290/1598296/117+11840/193i8296/117-11840/193i2782/697=108.7km/h.這與從驅(qū)動(dòng)力—行駛阻力平衡圖觀察結(jié)果一致。最大爬坡度的求解見(jiàn)(4)。(3)繪制加速度倒數(shù)曲線,其中,;,;,;,;由以上條件繪出圖形如下:數(shù)據(jù)表格見(jiàn):《附表二》(4)繪制汽車動(dòng)力因數(shù)特性曲線,,,;,;,;;由以上條件求出D,并畫(huà)出圖像如下:數(shù)據(jù)表格見(jiàn):《附表三》求解如下:欲求,只需求,用MAITLAB求解如下:先令,求解y’=0的根>>y=[-5.68,176.
3、76,-1852.34,6505.08]y=-142/254419/25-92617/5084566/13>>yx=poly2str(y,'x')yx=-5.68x^3+176.76x^2-1852.34x+6505.08>>formatrat%>>r=roots(y)r=2593/237+1397/676i2593/237-1397/676i1903/206得到對(duì)應(yīng)的速度=1903/206=9.24km/h,此時(shí)=0.428(4)二檔車速——時(shí)間曲線,距離——時(shí)間曲線MATLAB程序如下:>>t=cumtrapz(uat,adt)/3.6;t70=max(t);
4、figure(1),plot(t,uat,'b','LineWidth',1.5);title('二檔起步的車速—時(shí)間曲線');ylabel('ua(km/h)');xlabel('t(s)');gridon;Sa=cumtrapz(t,uat)/3.6;figure(2),plot(t,Sa,'b','LineWidth',1.5);title('二檔起步的距離—時(shí)間曲線');ylabel('S(m)');xlabel('t(s)');(二)汽車燃料經(jīng)濟(jì)性計(jì)算(1)求汽車功率平衡圖;;;由以上條件可計(jì)算出,并畫(huà)出曲線;,可畫(huà)出曲線如下:數(shù)據(jù)表格見(jiàn):《附表四》(2
5、)求最高擋和次高檔的等速百公里油耗曲線;;取8.00N/L;;;;由以上這些條件可求出,并畫(huà)出曲線如下:(Qs單位:L)數(shù)據(jù)表格:nuaPebQs4ig482019.619519732.48215644753.097919511.67621456120028.711492284.115953076599.967109510.54027479160038.281989716.428622686558.929866911.50245632200047.852487149.547593942454.886249611.12249132260062.2082332816.
6、17881262379.778013212.10426539300071.778730722.19543041344.773363413.06505805340081.3492281329.72386379343.761266315.39283477388092.8338250441.03739859310.274171516.80850328nuaPebQs3ig382011.609183271.357433164980.580496914.05108563120016.989048692.086663267863.948015413.0041138316002
7、2.652064922.977105295838.39008213.50337632200028.315081154.034593844734.692609212.82913937260036.809605496.025392456688.876281413.8189565300042.472621727.683204435629.361835113.95222798340048.135637959.654228637651.867896216.02213114388054.9312574212.49169819676.130413518.84266189(2)求
8、該貨車6工