Decomposition Analysis of an Automotive Powertrain Design ...

Appendix B: Parameters in Optimization Model
Table B.1: Summary of optimization model parameters.
Variable Description Value Units
τ 0 Baseline 0-60 mph time 11 sec
τ 1 Baseline 5-20 mph time 1.81 sec
S o-4 Distance traveled 4 seconds on max. accel 88.4 ft
α s Grade limit 30 %
V c Cruising speed @ grade 65 mph
A Vehicle frontal area 22.7 ft 2
Cd Vehicle body drag coefficient .33
Hcg Height of center of gravity 20.5 in
M g Weight of vehicle 3537 lbf
Ld Distance from center of gravity to driving axle 40.28 in
Lnd Distance from center of gravity to non-driving axle 65.72 in
Lw Wheelbase 106 in
Sw Length of axle 60.2 in
re Effective tire radius 12.24 in
µo Coefficient of adhesion 1.00
Id Rotational inertia of driving wheel .62 lbf-ft-sec 2
Ind Rotational inertia of non-driving wheel .62 lbf-ft-sec 2
ngears Number of gears in gearbox 4
Ifd Rotational inertia of differential .0124 lbf-ft-sec 2
It Rotational inertia of torque converter turbine .0874 lbf-ft-sec 2
Ii Rotational inertia of torque converter impeller .0293 lbf-ft-sec 2
Ie Rotational inertia of engine .164 lbf-ft-sec 2
Nidle Engine idle speed 700 rpm
vtype Valvetrain type pushrod
etype Engine type V
Cstiff Valvetrain stiffness factor .970
Cs System discharge coefficient .325
Cm Manifold discharge coefficient .650
Cp Port discharge coefficient .413
nbm Number of main bearings 4
ηcat Catalyst NOx effiecincy 0.90