汽车理论动力性燃油经济性计算.docx

1、汽车理论动力性燃油经济性计算期中试题动力性燃油经济性计算整车参数表 参数值参数参数值装载质量/kg1990飞轮转动惯量/（kg.m2）0.218整车整备质量/kg1890二前轮转动惯量/（kg.m2）1.798车轮半径/m0.367四后轮转动惯量/（kg.m2）3.598传动系机械效率0.85变速器5档滚动阻力系数f0.013轴距L/m3.2空气阻力系数*迎风面积/m22.77质心距前轴距离a（满载）/m1.947主减速器传动比5.83质心高（满载）/m0.9变速器速比1档2档3档4档5档五档变速器5.562.7691.6441.00.793拟合公式系数（r/min）B0B1B2B3B4815

2、1326.8-416.4672.379-5.86290.1776812071354.7-303.9836.657-2.05530.04307216141284.4-189.7514.524-0.511840.00681620121122.9-121.597.0035-0.185170.00185526031141.0-98.8934.4763-0.0910770.00068930061051.2-73.7142.8593-0.051380.00035034031233.9-84.4782.9788-0.0474490.00028238041129.7-45.2910.71113-0.00075

3、2-0.000038542001055.6-40.3120.52431-0.000372-0.00001021、绘制功率平衡图：根据公式，将各参数代入公式得发动机转速对应的车速；根据负荷特性曲线的拟合公式可以得到转矩；根据公式，计算功率；1档数值：n/（r/min）/（km/h）（N.m）（kw）00008153.564131.881411.254812075.278159.783120.194616147.058172.064429.079820128.798174.981136.8651260311.383172.749347.0855300613.145169.724653.423334

4、0314.881164.887858.7553380416.635154.904161.7021420018.367134.539259.1691MATLAB程序：车速：n=0 815 1207 1614 2012 2603 3006 3403 3804 4200;y=0.00437306*n转矩：p=-3.8445 40.875 -165.441 295.28 -19.313; n=0 0.815 1.207 1.614 2.012 2.603 3.006 3.403 3.804 4.200; T=polyval(p,n)功率：p=-3.8445*10-12 40.875*10-9 -0.0

5、00165441 0.29528 -19.313 0;n=0 815 1207 1614 2012 2603 3006 3403 3804 4200;P=polyval(p,n)/9550一档的功率特性图：a=0 3.5640 5.2783 7.0581 8.7986 11.3831 13.1454 14.8815 16.6351 18.3669;b=0 11.2548 20.1946 29.0798 36.8651 47.0855 53.4233 58.7553 61.7021 59.1691;values = spcrv(a(1) a a(end);b(1) b b(end),3);plo

6、t(values(1,:),values(2,:), g);2档数值：n/（r/min）/（km/h）（N.m）（kw）0008157.1564131.881411.2548120710.5985159.783120.1946161414.1723172.064429.0798201217.6671174.981136.8651260322.8566172.749347.0855300626.3953169.724653.4233340329.8813164.887858.7553380433.4024154.904161.7021420036.8797134.539259.1691MATLA

7、B程序：车速：n=0 815 1207 1614 2012 2603 3006 3403 3804 4200;y=0.008780872772*n转矩：p=-3.8445 40.875 -165.441 295.28 -19.313; n=0 0.815 1.207 1.614 2.012 2.603 3.006 3.403 3.804 4.200; T=polyval(p,n)功率：p=-3.8445*10-12 40.875*10-9 -0.000165441 0.29528 -19.313 0;n=0 815 1207 1614 2012 2603 3006 3403 3804 4200

8、;P=polyval(p,n)/9550二档的功率特性图：a= 0 7.1564 10.5985 14.1723 17.6671 22.8566 26.3953 29.8813 33.4024 36.8797;b=0 11.2548 20.1946 29.0798 36.8651 47.0855 53.4233 58.7553 61.7021 59.1691;values = spcrv(a(1) a a(end);b(1) b b(end),3);plot(values(1,:),values(2,:), g);3档数值：n/（r/min）/（km/h）（N.m）（kw）00081512.0

9、536131.881411.2548120717.8511159.783120.1946161423.8705172.064429.0798201229.7586174.981136.8651260338.4975172.749347.0855300644.4578169.724653.4233340350.3293164.887858.7553380456.2599154.904161.7021420062.1167134.539259.1691MATLAB程序：车速：n=0 815 1207 1614 2012 2603 3006 3403 3804 4200;y=0.014789681*

10、n转矩：p=-3.8445 40.875 -165.441 295.28 -19.313; n=0 0.815 1.207 1.614 2.012 2.603 3.006 3.403 3.804 4.200; T=polyval(p,n)功率：p=-3.8445*10-12 40.875*10-9 -0.000165441 0.29528 -19.313 0;n=0 815 1207 1614 2012 2603 3006 3403 3804 4200;P=polyval(p,n)/9550三档的功率特性图：a=0 12.0536 17.8511 23.8705 29.7568 38.4975

11、 44.4578 50.3293 56.2599 62.1167;b=0 11.2548 20.1946 29.0798 36.8651 47.0855 53.4233 58.7553 61.7021 59.1691;values = spcrv(a(1) a a(end);b(1) b b(end),3);plot(values(1,:),values(2,:), g);4档数值：n/（r/min）/（km/h）（N.m）（kw）00081519.8161131.881411.2548120729.3473159.783120.1946161439.2432172.064429.079820

12、1248.9202174.981136.8651260363.2900172.749347.0855300673.0886169.724653.4233340382.7413164.887858.7553380492.4914154.904161.70214200102.1198134.539259.1691MATLAB程序：车速：n=0 815 1207 1614 2012 2603 3006 3403 3804 4200;y=0.024314236*n转矩：p=-3.8445 40.875 -165.441 295.28 -19.313; n=0 0.815 1.207 1.614 2.0

13、12 2.603 3.006 3.403 3.804 4.200; T=polyval(p,n)功率：p=-3.8445*10-12 40.875*10-9 -0.000165441 0.29528 -19.313 0;n=0 815 1207 1614 2012 2603 3006 3403 3804 4200;P=polyval(p,n)/9550四档的功率特性图：a=0 19.8161 29.3473 39.2432 48.9202 63.2900 73.0886 82.7413 92.4914 102.1198;b=0 11.2548 20.1946 29.0798 36.8651 4

14、7.0855 53.4233 58.7553 61.7021 59.1691;values = spcrv(a(1) a a(end);b(1) b b(end),3);plot(values(1,:),values(2,:), g);5档数值：n/（r/min）/（km/h）（N.m）（kw）00081524.9888131.881411.2548120737.0079159.783120.1946161449.4870172.064429.0798201261.6901174.981136.8651260379.8108172.749347.0855300692.1672169.72465

15、3.42333403104.3397164.887858.75533804116.6347154.904161.70214200128.7765134.539259.1691MATLAB程序：车速：n=0 815 1207 1614 2012 2603 3006 3403 3804 4200;y=0.030661079*n转矩：p=-3.8445 40.875 -165.441 295.28 -19.313; n=0 0.815 1.207 1.614 2.012 2.603 3.006 3.403 3.804 4.200; T=polyval(p,n)功率：p=-3.8445*10-12 4

16、0.875*10-9 -0.000165441 0.29528 -19.313 0;n=0 815 1207 1614 2012 2603 3006 3403 3804 4200;P=polyval(p,n)/9550五档的功率特性图：a=0 24.9888 37.0079 49.4870 61.6901 79.8108 92.1672 104.3397 116.6347 128.7765;b=0 11.2548 20.1946 29.0798 36.8651 47.0855 53.4233 58.7553 61.7021 59.1691;values = spcrv(a(1) a a(end

17、);b(1) b b(end),3);plot(values(1,:),values(2,:), g);hold ongrid on6、阻力功率：根据公式阻力功率=MATLAB程序求阻力功率y=0.0000428 0 0.0803 0; u=0 24.9888 37.0079 49.4870 61.6901 79.8108 92.1672 104.3397 116.6347 128.7765; p=polyval(y,u)阻力功率图：a=0 24.9888 37.0079 49.4870 61.6901 79.8108 92.1672 104.3397 116.6347 128.7765; b

18、=0 2.6745 5.1411 9.1608 15.0020 28.1673 40.9109 56.9960 77.2747 101.7423; values = spcrv(a(1) a a(end);b(1) b b(end),3);plot(values(1,:),values(2,:), g);汽车功率平衡图如下：2、绘制最高档和次高档的等速百公里油耗线。（1）、最高档的参数值：根据燃油消耗率的特性拟合公式：计算燃油消耗率；再根据公式计算百公里燃油消耗量；n/（r/min）/（km/h）b/（g/kw.h）Q/（L/100km）（kw）001326.80081524.9888300.

19、410618.950011.2548120737.0079402.111130.731820.1946161449.4870336.301327.681329.0798201261.6901308.346525.807236.8651260379.8108288.069423.802647.0855300692.1672293.254123.806753.42333403104.3397293.793923.170858.75533804116.6347306.821922.733161.70214200128.7765303.799819.550059.1691MATLAB程序：a=24.9

20、888 37.0079 49.4870 61.6901 79.8108 92.1672 104.3397 116.6347 128.7765; b=18.9500 30.7318 27.6813 25.8072 23.8026 23.8067 23.1708 22.7331 19.5500; values = spcrv(a(1) a a(end);b(1) b b(end),3);plot(values(1,:),values(2,:), g);（2）次高档的参数值：n/（r/min）/（km/h）b/（g/kw.h）Q/（L/100km）（kw）001326.80081519.816130

21、0.410623.896611.2548120729.3473402.111138.753820.1946161439.2432336.301334.902629.0798201248.9202308.346532.543836.8651260363.2900288.069430.015947.0855300673.0886293.254130.021153.4233340382.7413293.793929.219358.7553380492.4914306.821928.667361.70214200102.1198303.799824.653259.1691MATLAB程序：a=19.8161 29.3473 39.2432 48.9202 63.2900 73.0886 82.7413 92.4914 102.1198; b=23.8966 38.7538 34.9026 32.5438 30.0159 30.0211 29.2193 28.6673 24.6532; values = spcrv(a(1) a a(end);b(1) b b(end),3);plot(values(1,:),values(2,:), r);得到百公里燃油消耗量曲线：