汽车理论动力性燃油经济性计算.docx
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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/kg
1990
飞轮转动惯量
/(kg.m2)
0.218
整车整备质量/kg
1890
二前轮转动惯量
/(kg.m2)
1.798
车轮半径/m
0.367
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f
0.013
轴距L/m
3.2
空气阻力系数*迎风面积/m2
2.77
质心距前轴距离a(满载)/m
1.947
主减速器传动比
5.83
质心高
(满载)/m
0.9
变速器速比
1档
2档
3档
4档
5档
五档变速器
5.56
2.769
1.644
1.0
0.793
拟合公式系数
(r/min)
B0
B1
B2
B3
B4
815
1326.8
-416.46
72.379
-5.8629
0.17768
1207
1354.7
-303.98
36.657
-2.0553
0.043072
1614
1284.4
-189.75
14.524
-0.51184
0.006816
2012
1122.9
-121.59
7.0035
-0.18517
0.001855
2603
1141.0
-98.893
4.4763
-0.091077
0.000689
3006
1051.2
-73.714
2.8593
-0.05138
0.000350
3403
1233.9
-84.478
2.9788
-0.047449
0.000282
3804
1129.7
-45.291
0.71113
-0.000752
-0.0000385
4200
1055.6
-40.312
0.52431
-0.000372
-0.0000102
1、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)
0
0
0
0
815
3.564
131.8814
11.2548
1207
5.278
159.7831
20.1946
1614
7.058
172.0644
29.0798
2012
8.798
174.9811
36.8651
2603
11.383
172.7493
47.0855
3006
13.145
169.7246
53.4233
3403
14.881
164.8878
58.7553
3804
16.635
154.9041
61.7021
4200
18.367
134.5392
59.1691
MATLAB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^-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=spcrv([[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)
0
0
0
815
7.1564
131.8814
11.2548
1207
10.5985
159.7831
20.1946
1614
14.1723
172.0644
29.0798
2012
17.6671
174.9811
36.8651
2603
22.8566
172.7493
47.0855
3006
26.3953
169.7246
53.4233
3403
29.8813
164.8878
58.7553
3804
33.4024
154.9041
61.7021
4200
36.8797
134.5392
59.1691
MATLAB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^-9-0.0001654410.29528-19.3130];
n=[081512071614201226033006340338044200];
P=polyval(p,n)/9550
二档的功率特性图:
a=[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)
/(km/h)
(N.m)
(kw)
0
0
0
815
12.0536
131.8814
11.2548
1207
17.8511
159.7831
20.1946
1614
23.8705
172.0644
29.0798
2012
29.7586
174.9811
36.8651
2603
38.4975
172.7493
47.0855
3006
44.4578
169.7246
53.4233
3403
50.3293
164.8878
58.7553
3804
56.2599
154.9041
61.7021
4200
62.1167
134.5392
59.1691
MATLAB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^-1240.875*10^-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)
/(km/h)
(N.m)
(kw)
0
0
0
815
19.8161
131.8814
11.2548
1207
29.3473
159.7831
20.1946
1614
39.2432
172.0644
29.0798
2012
48.9202
174.9811
36.8651
2603
63.2900
172.7493
47.0855
3006
73.0886
169.7246
53.4233
3403
82.7413
164.8878
58.7553
3804
92.4914
154.9041
61.7021
4200
102.1198
134.5392
59.1691
MATLAB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^-1240.875*10^-9-0.0001654410.29528-19.3130];
n=[081512071614201226033006340338044200];
P=polyval(p,n)/9550
四档的功率特性图:
a=[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)
/(km/h)
(N.m)
(kw)
0
0
0
815
24.9888
131.8814
11.2548
1207
37.0079
159.7831
20.1946
1614
49.4870
172.0644
29.0798
2012
61.6901
174.9811
36.8651
2603
79.8108
172.7493
47.0855
3006
92.1672
169.7246
53.4233
3403
104.3397
164.8878
58.7553
3804
116.6347
154.9041
61.7021
4200
128.7765
134.5392
59.1691
MATLAB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^-1240.875*10^-9-0.0001654410.29528-19.3130];
n=[081512071614201226033006340338044200];
P=polyval(p,n)/9550
五档的功率特性图:
a=[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');
holdon
gridon
6、阻力功率:
根据公式阻力功率=
MATLAB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:
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)
0
0
1326.8
0
0
815
24.9888
300.4106
18.9500
11.2548
1207
37.0079
402.1111
30.7318
20.1946
1614
49.4870
336.3013
27.6813
29.0798
2012
61.6901
308.3465
25.8072
36.8651
2603
79.8108
288.0694
23.8026
47.0855
3006
92.1672
293.2541
23.8067
53.4233
3403
104.3397
293.7939
23.1708
58.7553
3804
116.6347
306.8219
22.7331
61.7021
4200
128.7765
303.7998
19.5500
59.1691
MATLAB程序:
a=[24.988837.007949.487061.690179.810892.1672104.3397116.6347128.7765];
>>b=[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/(r/min)
/(km/h)
b/(g/kw.h)
Q/(L/100km)
(kw)
0
0
1326.8
0
0
815
19.8161
300.4106
23.8966
11.2548
1207
29.3473
402.1111
38.7538
20.1946
1614
39.2432
336.3013
34.9026
29.0798
2012
48.9202
308.3465
32.5438
36.8651
2603
63.2900
288.0694
30.0159
47.0855
3006
73.0886
293.2541
30.0211
53.4233
3403
82.7413
293.7939
29.2193
58.7553
3804
92.4914
306.8219
28.6673
61.7021
4200
102.1198
303.7998
24.6532
59.1691
MATLAB程序:
a=[19.816129.347339.243248.920263.290073.088682.741392.4914102.1198];
>>b=[23.896638.753834.902632.543830.015930.021129.219328.667324.6532];
>>values=spcrv([[a
(1)aa(end)];[b
(1)bb(end)]],3);
plot(values(1,:
),values(2,:
),'r');
得到百公里燃油消耗量曲线: