PERFORMANCE OF DRIVE TRAIN

If a driver wants to keep its speed constant, he needs to have equivalent engine power to the running resistance but needs more power for acceleration to overcome the acceleration resistance. In the case of deceleration of the vehicle, the inertia energy of the vehicle can be restored by the inertia energy recovery system of the vehicle. The engine power required for driving changes at all the time due to the variation of moving condition on a road.

In here, the mathematical equations of the resistance terms are introduced to make the governing equation of the power train system of a vehicle. In general, the running resistance terms on a moving vehicle consist of:

- Rolling resistance

- Aerodynamic resistance

- Gradient resistance

A general form of total running resistance force of a vehicle can be expressed as the summation of above terms as given below:

Rt = R_{A} + R_{R} + R_{G} |
(1) |

With the change of driving condition, the general equation Eq. (1) should be modified.

*Rolling resistance*

The friction resistance between road and tire surface is defined as rolling resistance of a vehicle. It is clearly affected to the surface roughness of road but not to the vehicle speed. From the principle of physics, the rolling resistance of a running vehicle can be obtained from Eq. (2):

R_{R} = K x W |
(2) |

Where, K – constant of rolling resistance, depends on the nature of road = 0.015 for loose unpaved road. W – Weight of the vehicle = 250 x 9.81 = 2452.5N (Let)

Therefore, R_{R} = 36.79N

Where W is gross weight of a vehicle and W is the induced lift or down force on a running vehicle.

The rolling resistance coefficient (K ) depends on surface condition of road, material and tread pattern of tires and its charged air pressure and vehicle speed etc. Thus the multiple factors affecting rolling resistance cannot be taken into account at a time. In here, the most commonly used coefficient varied with road surface condition is incorporated in this study table.

TABLE 2: VARIATION OF ROLLING RESISTANCE COEFFICIENT WITH ROAD SURFACE CONDITION.

Road surface |
Rolling resistance coefficient Fr |

Firm Road condition | 0.010 – 0.035 |

Unmade road surface | 0.045 to 0.300 |

ATV | 0.3 |

*Aerodynamics Resistance*

As a vehicle runs on a road, the relative air movement occurs opposite to the driving direction of the vehicle even with no wind in air. Because of this air flow, the vehicle experiences aerodynamic force such as drag and lift on the body. The aerodynamic drag force generated on the frontal and rear side of the body acts on the vehicle as a driving resistance.

From the analytical equation in Eq. (3), the aerodynamic drag force can be estimated.

R_{A} = (1/2)ρA_{f} C_{d}(V/3.6)^{2} |
(3) |

ρ – Density of air A_{f} – Projected frontal area C_{d} _{–} coefficient of aerodynamics resistance V– Velocity of the vehicle

As a vehicle goes up or down the hill, it experiences gravitational resistance due to its weight and it is called gradient resistance of the vehicle.

http://upload.wikimedia.org/wikipedia/commons/thumb/4/4c/AASHTOSSD.png/400px-AASHTOSSD.png

The gradient resistant is calculated by Eq. (4):

RG = W sinθ | (4) |

Where θ is gradient angle of road.

The vehicle is desired to be able to climb a 30 degree slope while carrying the heaviest of the team’s drivers.

Hence θ = 30°

Velocity of Vehicle, Power of propulsion, Tractive effort, road performance and gearbox selection ………. coming soon

For more information on Manual Transmission drop a mail or comment below.

I WANT TO KNOW THAT WHAT ARE THE FACTORS THAT MUST BE TAKEN INTO CONSIDERATION WHILE SELECTING A MANUAL TRANSMISSION FOR AN ATV?

Many factors are taken into account while selecting a manual transmission, some of those I have considered are top speed of vehicle after reduction, torque that will be available, weight , availability, size as per your dimensions etc.

I WANT TO KNOW THAT WHAT ARE THE FACTORS THAT MUST BE TAKEN INTO CONSIDERATION WHILE SELECTING A MANUAL TRANSMISSION FOR AN ATV?

Need help regarding traction calculations and torque required for a hill climb of 45 deg…

Many factors are taken into account while selecting a manual transmission, some of those I have considered are top speed of vehicle after reduction, torque that will be available, weight , availability, size as per your dimensions etc.

part 2??

We will upload it soon

Need help regarding traction calculations and torque required for a hill climb of 45 deg…

Where is Part 2??

We will upload it soon

Where is Part 2??

We will upload it soon

Need help regarding calculations for gradability and traction

mail us to bajatutor@gmail.com

Need help regarding calculations for gradability and traction

mail us to bajatutor@gmail.com

part 2??

We will upload it soon

I need formulas to calculate the values for a gear box can any one provide it please……..

We have sent it. Pls check your mail.

I need formulas to calculate the values for a gear box can any one provide it please……..

We have sent it. Pls check your mail.

Can you help me with gear box selection?

Sure. Narendra. Send us the constraints like : placement of engine I.e. mounting and rear part spacing. How far have you gone info design and what are your expectations from your buggy.

Mail to – bajatutor@gmail.com

Can you help me with gear box selection?

Sure. Narendra. Send us the constraints like : placement of engine I.e. mounting and rear part spacing. How far have you gone info design and what are your expectations from your buggy.

Mail to – bajatutor@gmail.com

Velocity of Vehicle, Power of propulsion, Tractive effort, road performance …sir when will you upload this?

Velocity of Vehicle, Power of propulsion, Tractive effort, road performance …sir when will you upload this?

sir, what is grade ability and bar pull of vehical?

sir, what is grade ability and bar pull of vehical?

plz provide sufficient info about the transmission system

Hello Waqar, can you be a bit more clear as to what information are you looking for. You can mail us at help@bajatutor.net

I am a bit confused about the calculations of gradeability and sledge pull. Do we need to add the overcoming torque after calculating the torque required to pull the weight and do we need to consider any slope?

Which type of weight we have to put in these calculations, with driver or without driver?