sem - getting better fuel economy 2

7/24/2019 SEM - Getting Better Fuel Economy 2

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Copyright of Shell Global Solutions Sdn. Bhd.

SHELL ECO-MARATHON CARTECHNOLOGIES FOR FUEL EFFICIENCY

Colin Chin

Shell Global Solutions

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Shell Eco-marathon Objectives

It is not just about building a car

It is about building a fuel efficient car

October 2011 2


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Top Teams

1.0

Aug 2014 3


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SEM 2014 Europe Winner Prototype Gasoline

La Joliverie Projet Microjoule

Prototype Gasoline (Petrol)

3314.9 km/l


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Top Teams

Enablers

Streamlined body

Internal wheels Light vehicle (and components)

Low friction

Simplicity

Consume < 5 ml for entire run

Small engine

Use the engine only 2-3 timesper lap

Free-wheels most of the time

October 2011 5

Learn from the top teams


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Concepts

2.0


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Energy & the Engine

Why is The Engine Used?

To accelerate

To keep moving

Energy

The less energy needed to do the above, the less fuel is consumed

How far can your car go if you give it a push?

Winning cars may go as far as 80 m with a single push

October 2011 7

5 m?

80 m?

Push


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How to Use Less Fuel?

October 2011 8

Smallerengine

Lighter car

Less engineuse

Less drag

Less friction

Bearings

Drive train

Engine

Rolling resistance Tyres

Lubrication

Glide

Design

Efficient components

ElectronicsOptimumconditions

Tuning/ settingsSpeed

Driving style


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Consider

Everything Counts

October 2011 9

Weight

Wheels Drive train Engine

Drag

Bearings

Driver

Efficiency

Friction

Weight

Brakes

Settings

Battery Body Specs


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Technologies Employed in SEM Cars

Reduce weight by use of

Innovative light weight materials

Optimized selection of engineand vehicle components

Fuel / power train optimization Computerized fuel injection and

timing

Advanced electronics andcomputer control

To improve efficiency varioustechnologies are employed:

Reduce friction/drag

Special tyres

Aerodynamic design Low viscosity engine oil / gear oil

Low friction engines

Low friction bearings &

components


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Aerodynamic Design

To reduce drag


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Engine

Engine selection

A large an engine is heavy and will consume more fuel

It should be small, but powerful enough to move the car up a hill Engine friction (materials and lubrication)

Hub motors in BEV may not be the most efficient

Engine optimization

Compression ratio

Timing

Fuel injection/carburetor

Air/Fuel mixture

Injector condition


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Engine Size

October 2011 13

Engine


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Tyres

Low friction tyres to reducerolling resistance

Design

What is the best size?What is the best profile?

Weight

Covered tyres for reduced windresistance

Correct tyre inflation

Underinflated tyres can give highfuel consumption

Correct alignment andbalancing


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Reducing Internal Friction

Low friction bearings Low viscosity engine oil


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Drive Train

What is the most efficient drive train?

Belt, chain, gear?

Friction Reliability

Ensure that your drive train is as efficient as possible Correct gear/chain ratios

Sufficient gear ratios

Dis-engagement from engine during when free-wheeling

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Minimize Weight

Component selection/design

Engine

Drive train Chassis

Body

Steering system

Battery size

Light weight materials

Carbon fibre

Plastic


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Optimized Components

Every component contributes to fuel efficiency

Keep the design simple

Does the component need to be there? Is it the right size/capacity (will a smaller unit work)?

Can it be removed?

Can it be replaced by a more efficient system/component? Can it be made of a different material?

Is it too heavy (can a lighter version be used) ?


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Optimized Components

Settings

Is the engine tuned correctly (engine timing)?

Is the fuel injection timing correct? Fuel pressure

Tyre pressure, alignment

Gear ratios

Properly lubricated?


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Fuel Injection Systems

Carburetors are not as efficient

Fuel injection systems help control the amount of fuel used thereby

improving fuel efficiency (this is now common in the auto industry)


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Advanced Electronics and Computer Control

Advanced electronics and computer control can be used to optimizefuel usage and car settings


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Driving Strategy

Driving strategy also plays an important role in efficiency

Manage the speed

Dont accelerate unnecessarily High speed doesnt give good efficiency

Drive smoothly

Racing line It is not necessary to have the engine running all the time

Plan when you need to use the engine

Make use of gravity

Coast when possible

Drive with the correct gear for the speed of the vehicle


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Test Your Car

Find out the most efficient operating conditions for your car before therace:

Tyre inflation Speed

Engine cut off

Gearing Engine tuning

Best driver

Do the Push Test !


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sem - getting better fuel economy 2

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