汽车理论动性,燃油经济性计算.doc

《汽车理论动性,燃油经济性计算.doc》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、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）B0B1B2B3B4

2、8151326.8-416.4672.379-5.86290.1776812071354.7-303.9836.657-2.05530.04307216141284.4-189.7514.524-0.511840.00681620121122.9-121.597.0035-0.185170.00185526031141.0-98.8934.4763-0.0910770.00068930061051.2-73.7142.8593-0.051380.00035034031233.9-84.4782.9788-0.0474490.00028238041129.7-

3、45.2910.71113-0.000752-0.000038542001055.6-40.3120.52431-0.000372-0.00001021、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

4、.749347.0855300613.145169.724653.4233340314.881164.887858.7553380416.635154.904161.7021420018.367134.539259.1691MATLAB程序：车速：n=[081512071614201226033006340338044200];y=0.00437306*n转矩：p=[-3.844540.875-165.441295.28-19.313];>>n=[00.8151.2071.6142.0122.6033.0063.4033.8044.200];>>T=poly

5、val(p,n)功率：p=[-3.8445*10^-1240.875*10^-9-0.0001654410.29528-19.3130];n=[081512071614201226033006340338044200];P=polyval(p,n)/9550一档的功率特性图：a=[03.56405.27837.05818.798611.383113.145414.881516.635118.3669];b=[011.254820.194629.079836.865147.085553.423358.755361.702159.1691];values=spc

6、rv([[a(1)aa(end)];[b(1)bb(end)]],3);plot(values(1,:),values(2,:),'g');2档数值：n/（r/min）/（km/h）（N.m）（kw）0008157.1564131.881411.2548120710.5985159.783120.1946161414.1723172.064429.0798201217.6671174.981136.8651260322.8566172.749347.0855300626.3953169.724653.4233340329.8813164.887858.755

7、3380433.4024154.904161.7021420036.8797134.539259.1691MATLAB程序：车速：n=[081512071614201226033006340338044200];y=0.008780872772*n转矩：p=[-3.844540.875-165.441295.28-19.313];>>n=[00.8151.2071.6142.0122.6033.0063.4033.8044.200];>>T=polyval(p,n)功率：p=[-3.8445*10^-1240.875*10^-9-0.0001654410.2

8、9528-19.3130];n=[081512071