May – June 2020 ISSN: 0193-4120 Page No. 16434 – 16444 16438
Published by The Mattingley Publishing Co, Inc. Gross Vehicle Weight:
1.3-1.4 Tonnes
1.5 Tonnes
Acceleration: 0-100 KMPH
(15 secs)
0-100 KMPH
(9 secs) Under the consideration that the standard Curb Weight of the Sedan is about 860 - 985 Kgs, the table describes the difference in the parameters when the sedan is stripped off the ICE and introduced to a Battery-Motor drive system. As the rating for the motor is considered
higher for faster acceleration, the weight of the motor, batteries and the overall vehicle tend to increase but promise to stay in a good range. Some very important calculations for Torque and speed are given proceeding.
C. Calculations The amount of torque exerted by the internal combustion engine in the first gear of operation is said to be the maximum torque applied by the engine to the vehicle. This is so because initially the vehicle needs large torque to move from its initial position of rest to a forward or reverse momentum. This maximum torque of operation is considered as the maximum torque that the motor should possess in order to drive the vehicle. Keeping this under consideration, the torque on the motor and the required speed on the motor axle is calculated using formulae subjected in [16].
1) Rolling Resistance The Rolling resistance is a measure of opposing force the vehicle has to overcome during rolling or moving. RR = ttV W
∗Crr
(1) Consider Eqn (1). If the coefficient of rolling friction is considered for
Good asphalt conditions as 0.012, then the Rolling resistance can be given by RR = ttV W
∗ (0.012) As the GVW is considered to be 1.5 Tonnes, the RR can be given by RR = Kg
(2)
2) Grade Resistance The Grade Resistance is a form of gravitational force acting on the vehicle body. ttR = ttV W sin
(3) Consider in Eqn (3), the gradient of inclination is considered as (5)
and the GVW, then, we can have ttR = ttV W
∗ (0.0871) The Grade Resistance can be given by ttR = Kg
(4)
3) Acceleration Force The Acceleration force is the force that helps a vehicle reach its predefined speed in record time. FA = (ttV W/g)
∗ a
(5) Given the time of acceleration is considered to be 9 seconds, the acceleration is calculated as a = (vf − v0)/t a = 100/9 = ms Using this in Eqn (5) and gas 9.81 ms, we have the acceleration force to be FA = Kg
(6)
4) Total Tractive Effort The total force required to move the vehicle in its desired range is known as Total Tractive effort. It is basically defined as the sum of all the forces.
TTE = RR + ttR + FA TTE = 16.4 + 119 + 1542
TTE = Kg The TTE is given as
TTE = 16.44kN
(7)
5) Torque The Torque required by the motor for the
given conditions is given by τ = Rf TTE ∗rwheel Considering from Eqn (6), the radius of the wheel to be 17 inches, for 1.1 friction,
the torque is given by τ = 3.075kN
(8)
