6 汽车总体性能计算6.1 汽车动力性计算6.1.1 汽车各档车速计算各挡车速的计算公式如下：rnu 二 0.377—(km/h)(6T)aiig0式中 r——汽车滚动半径，r=0.279m；n 发动机转速(r/min)；i——汽车变速器的传动比，i=3.17；i=2.158；i=1.469；i=1；gg1g2g3g4i 主减速器的传动比，i=5.01。00代入相关参数所得结果见表 6-1。表 6-1 汽车各档车速n(r/min)Ua1(km/h)Ua2(km/h)Ua(km/h)Ua4(km/h)10006.622919.7287414.2917720.9946112007.9474911.6744817.1501225.1935314009.2720713.6202320.0084829.39246160010.5966515.5659822.8668333.59138180011.9212317.5117225.7251937.79030200013.2458119.4574728.5835441.98922220014.5703921.4032231.4418946.18814240015.8949723.3489634.3002550.38707260017.2195525.2947137.1586054.58599280018.5441427.2404640.0169658.78491300019.8687229.1862142.8753162.98383320021.1933031.1319545.7336767.18275340022.5178833.0777048.5920271.38168360023.8424635.0234551.4503775.58060380025.1670436.9691954.3087379.77952400026.4916238.9149457.1670883.97844420027.8162040.8606960.0254488.17737440029.1407842.8064462.8837992.37629460030.4653744.7521865.7421496.57521480031.7899546.6979368.60050100.77413500033.1145348.6436871.45885104.973056.1.2 汽车行驶阻力计算汽车行驶阻力包括：滚动阻力、空气阻力、加速阻力和爬坡阻力。F+F 二 Gxf+fw21.21)滚动阻力滚动阻力计算公式：F=Gf(N)(6-2)f式中 G——汽车重力,G=14250N；f——滚动阻力系数,f=0.015。2)空气阻力空气阻力计算公式：F=CDAua(N)(6-3)w21.25式中 C 汽车的空气阻力系数 C=0.52；D——DA——汽车的迎风面积 A=2.726m2；U——汽车各档车速(km/h)。a代入相关参数有：2.726x0.52xu2a21.25所以，汽车的行驶阻力C D A 仃二 14250x0.015+2.726x0.52x 叮21.25所得结果见表 6-2。表 6-2 汽车各档行驶阻力(Ff+Fw)l(Ff+Fw)2(Ff+Fw)3(Ff+Fw)4216.67595220.06369227.37518243.15261217.96337222.84171233.37026256.08976219.48487226.12483240.45536271.37912221.24044229.91304248.63047289.02069223.23009234.20635257.89559309.01446225.45381239.00475268.25073331.36045227.91161244.30824279.69588356.05864230.60349250.11684292.23105383.10905233.52944256.43052305.85623412.51166236.68947263.24930320.5714344...
