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//f（kg.m2）0.218整车整备质量/kg1890二前轮转动惯量I/w1（kg.m2）1.798车轮半径/m0.367四后轮转动惯量I/w2（kg.m2）3.598传动系机械效率t0.85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质心距前车由距离a（满载）/m1.947主减速器传动比i05.83质心高h（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）B0B1B2B3B48151326.8-416.4672.379-5.86290.1776812071354.7-303.9836.657-2.05530.04307216141284.4-189.7514.524-0.511840.00681620121122.9-121.597.0035-0.185170.00185526031141.0-98.8934.4763-0.0910770.00068930061051.2-73.7142.8593-0.051380.00035034031233.9-84.4782.9788-0.0474490.00028238041129.7-45.2910.71113-0.000752-0.000038542001055.6-40.3120.52431-0.000372-0.00001021、绘制功率平衡图：根据公式u=0.377把,将各参数代入公式得发动机转速对应的车速;aii根据负荷特性曲线的拟合公式可以得到转矩；9550根据公式P=工，计算功率；

95501档数值:n/(r/min)u/(km/h)t (N.m)P(kw)00008153.564131.881411.254812075.278159.783120.194616147.058172.064429.079820128.798174.981136.8651260311.383172.749347.0855300613.145169.724653.4233340314.881164.887858.7553380416.635154.904161.7021420018.367134.539259.1691MATLAB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=polyval(p,n)功率：p=[-3.8445*10八-1240.875*10八-9-0.0001654410.29528-19.3130];n=[081512071614201226033006340338044200];P=polyval(p,n)/9550一档的功率特性图：a二[03.56405.27837.05818.798611.383113.145414.881516.635118.3669];b=[011.254820.194629.079836.865147.085553.423358.755361.702159.1691];values=spcrv([[a(1)aa(end)];[b(1)bb(end)]],3);plot(values(1,:),values(2,:),'g');2档数值：n/(r/min)u/(km/h)t (N.m)P(kw)0008157.1564131.881411.2548120710.5985159.783120.1946161414.1723172.064429.0798201217.6671174.981136.8651260322.8566172.749347.0855300626.3953169.724653.4233340329.8813164.887858.7553380433.4024154.904161.7021420036.8797134.539259.1691MATLAB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*10八-1240.875*10八-9-0.0001654410.29528-19.3130];n=[081512071614201226033006340338044200];P=polyval(p,n)/9550二档的功率特性图：a二[07.156410.598514.172317.667122.856626.395329.881333.402436.8797];b=[011.254820.194629.079836.865147.085553.423358.755361.702159.1691];values=spcrv([[a(1)aa(end)];[b(1)bb(end)]],3);plot(values(1,:),values(2,:),'g');3档数值：n/(r/min)u/(km/h)t (N.m)P(kw)000

81512.0536131.881411.2548120717.8511159.783120.1946161423.8705172.064429.0798201229.7586174.981136.8651260338.4975172.749347.0855300644.4578169.724653.4233340350.3293164.887858.7553380456.2599154.904161.7021420062.1167134.539259.1691MATLAB程序：车速：n=[081512071614201226033006340338044200];y=0.014789681*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*10八-1240.875*10八-9-0.0001654410.29528-19.3130];n=[081512071614201226033006340338044200];P=polyval(p,n)/9550三档的功率特性图：a=[012.053617.851123.870529.756838.497544.457850.329356.259962.1167];b=[011.254820.194629.079836.865147.085553.423358.755361.702159.1691];values=spcrv([[a(1)aa(end)];[b(1)bb(end)]],3);plot(values(1,:),values(2,:),'g');4档数值：n/(r/min)u/(km/h)t (N.m)P(kw)00081519.8161131.881411.2548120729.3473159.783120.1946161439.2432172.064429.0798201248.9202174.981136.8651260363.2900172.749347.0855300673.0886169.724653.4233340382.7413164.887858.7553380492.4914154.904161.70214200102.1198134.539259.1691MATLAB程序：车速：n=[081512071614201226033006340338044200];y=0.024314236*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*10八-1240.875*10八-9-0.0001654410.29528-19.3130];n=[081512071614201226033006340338044200];P=polyval(p,n)/9550四档的功率特性图：a二[019.816129.347339.243248.920263.290073.088682.741392.4914102.1198];b=[011.254820.194629.079836.865147.085553.423358.755361.702159.1691];values=spcrv([[a(1)aa(end)];[b(1)bb(end)]],3);plot(values(1,:),values(2,:),'g');5档数值：n/(r/min)u/(km/h)t (N.m)P(kw)00081524.9888131.881411.2548120737.0079159.783120.1946161449.4870172.064429.0798201261.6901174.981136.8651260379.8108172.749347.0855300692.1672169.724653.42333403104.3397164.887858.75533804116.6347154.904161.70214200128.7765134.539259.1691MATLAB程序：车速：n=[081512071614201226033006340338044200];y=0.030661079*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*10八-1240.875*10八-9-0.0001654410.29528-19.3130];n=[081512071614201226033006340338044200];P=polyval(p,n)/9550五档的功率特性图：a二[024.988837.007949.487061.690179.810892.1672104.3397116.6347128.7765];b=[011.254820.194629.079836.865147.085553.423358.755361.702159.1691];values=spcrv([[a(1)aa(end)];[b(1)bb(end)]],3);plot(values(1,:),values(2,:),'g');holdongridon6、阻力功率：GfuCAu3a+Da根据公式阻力功率=Pf+Pw=3600 76140“ 0.85MATLAB程序求阻力功率y=[0.000042800.08030];>>u=[024.988837.007949.487061.690179.810892.1672104.3397116.6347128.7765];>>p=polyval(y,u)阻力功率图：a=[024.988837.007949.487061.690179.810892.1672104.3397116.6347128.7765];>>b=[02.67455.14119.160815.002028.167340.910956.996077.2747101.7423];>>values=spcrv([[a(1)aa(end)];[b(1)bb(end)]],3);plot(values(1,:),values(2,:),'g');汽车功率平衡图如下：

iiMFigure1iiEditViewInsertToolsDesktopWindowHelpnhtewe⑨口口■□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:b=B+B•P+B•P2+B•P3+B-P4

0 1e2e3e4e计算燃油消耗率；再根据公式P,b1.02upga计算百公里燃油消耗量;n/(r/min)u((km/h)ab/(g/kw.h)Q/(L/100km)P(kw)001326.800

81524.9888300.410618.950011.2548120737.0079402.111130.731820.1946161449.4870336.301327.681329.0798201261.6901308.346525.807236.8651260379.8108288.069423.802647.0855300692.1672293.254123.806753.42333403104.3397293.793923.170858.75533804116.6347306.821922.733161.70214200128.7765303.799819.550059.1691MATLAB程序：a二[24.988837.007949.487061.690179.810892.1672104.3397116.6347128.7765];>b二[18.950030.731827.681325.807223.802623.806723.170822.733119.5500];>values=spcrv([[a(1)aa(end)];[b(1)bb(end)]],3);plot(values(1,:),values(2,:),'g');(2)次高档的参数值：n/