A Bit of Automobile Technology

It would be nice to shift to a non-electrical topic for a change. A brief explanation would be provided about the recent past & current technology available in cars.

Different kinds of Transmission systems:
MT: Manual Transmission - The Coventional Gear selection system
AT: Automatic Transmission - The Automatic Gear selection system
ManuMatic/Tiptronic/GearTronic: Manu(al + Auto)matic system
CVT: Continuously Variable Transmission

5 Speed manual transmission - gears

Automatic transmission lever

Above the letters indicate the following:
1. P - Park
2. R - Reverse
3. N - Neutral
4. D - Drive
5. 2 - Second gear is maximum
6. L - Low/1st gear is maximum

Tiptronic - A type of manumatic/semi-automatic trnasmission

Normally manual transmission employs a clutch but an auto transmission utilises a torque converter instead of clutch.

Few emission control systems:
CVCC: Compound Vortex Controlled Combustion by Honda for complying with emission standards
CC: Catalytic Converter used for treating toxic emissioons

Compound vortex controlled combustion employs a 2nd spark plug near inlet

Various ValveTrain systems:

The valvetrain system having camshaft, valves etc

VTEC: Variable Valve Timing and Lift Electronic Control by Honda
VVT-i : Variable Valve Timing with Intelligence developed by Toyota
SOHC: Single Over Head Camshaft system
DOHC: Double Over Head Camshaft system

Multiple Fuel delivery systems:
Carburettor:Conventional indirect injection
MFI: Mechanical Fuel Injection
EFI: Electronic Fuel Injection

Engine Efficiency Improvement systems:
Intercooler/Aftercooler:
Turbocharger/TurboSupercharger:

Close view of an intercooler - courtesy: wikipedia

A Typical Turbocharger

 Passenger Safety systems:
ABS: AntiLock Braking System
EBD: Electronic Brakeforce Distribution

Emerging Aotomobile Design technologies:
HEV: Hybrid Electric Vehicle cosists of an IC Engine and Electric motors

2010 Toyota Prius: claimed to be the the most efficient & cleanest hybrid

The 'energy screen' of the Prius - showing the interaction between electric motor, IC engine & batteries

Half-a-loaf of Automotive Aerodynamics (AA)

what is aerodynamics?
Aerodynamics is a branch of dynamics concerned with studying the motion of air, particularly when it interacts with a moving object as defined by wikipedia.

Aerodynamics of automobiles:

drag:
drag is a fluid dynamics term, sometimes called as air resistance or fluid resistance. It is defined as "forces that oppose the relative motion of an object through a fluid. Drag forces act in a direction opposite to the oncoming flow velocity". (wikipedia)

Shape and flow	Form drag	Skin friction
	0%	100%
	~10%	~90%
	~90%	~10%
	100%	0%

lift:
A fluid flowing past the surface of a body exerts a surface force on it. Lift is defined to be the component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag force, which is defined to be the component of the surface force parallel to the flow direction.(wikipedia)

Note: In aircrafts Lift/drag ratio is expected to be higher. But this is not the case in automobiles where lift is to be reduced and drag too to be reduced. What is especially required in an autombile such as a racing car is the downforce (as opposed to the lift required in aircrafts).

Upper: non-aerodynamic car; Lower: aerodynamically improved design
From: http://www.generalamherst.com

A diffuser is seen in most racing cars:

Rear diffuser of Porsche - Courtesy: Wikipedia

Rear spoiler of Toyota - Courtesy: Wikipedia

Front Air Dam of Mazda - Courtesy: Mazda

Please visit hotrod for a fine detailed description of the role of aerodynamics in automobiles!

Internal Combustion (IC) Engines

Internal combustion engines have been a compact method to drive a generator to produce mechanical energy. IC engines can be mainly classified into two.
1. Diesel engines (Compression-ignition)
2. Petrol/gasoline engines (Spark-ignition)
Diesel and Gasoline engines are reprocating engines too as 1/more pistons move laterally to generate rotational energy which in turn used as a prime mover for either generators or simply as marine engines to drive the propeller.

A 3D cut-away model of an internal combustion engine, showing cylinder, piston, crankshaft, camshaft, valves etc.

The injection of fuel (either diesel or gasoline) can be direct or indirect.

1. Direct injection is done by the help of specially designed fuel injectors. This is applicable mostly to diesel engines.
2. Indirect injection is where fuel is not directly INJECTED. Actually this suits to gasoline engines. A carburrettor helps to DRAW the fuel rather than injecting it to the engine.This is applicable mostly to petrol engines. In modern cars, a carburettor is replaced by ELECTRONIC FUEL INJECTION (EFI), where injection is controlled by electronic means normally by a dedicated controller.

4-stroke cycle:

1. Intake stroke
2. Compression stroke
3. Power stroke
4. Exhaust stroke

4 strokes in a 4 cylinder engine cross-section, note the relative timing

Main Parts of a diesel generator set:

Parts of a diesel engine, showing main mechanical parts  

Mechanical components:

1. cylinder liner
2. piston
3. connecting rod
4. crankshaft
5. camshaft
6. push rod
7. valve spring
8. air inlet valve
9. exhaust valve
10. injector nozzle
11. fuel pump
12. ac pump
13. fuel filter
14. oil filter
15. air filter
16. oil sump
17. fuel tank
18. flywheel
19. rocker arm
20. governor

A very detailed exploded view of a diesel engine, showing cylinder head, block, valve set, shafts, bearings, gaskets etc.

Electrical components:

1. starting motor
2. battery
3. charging alternator
4. gen stator
5. gen rotor
6. windings
7. MVR/ AVR/ DVR
8. DC generator/PM Generator - exciter
9. rotating diode set
10. oil pressure sensor
11. water temperature sensor
12. speed sensor
13. gen control panel (GCP)
14. gen circuit breaker (GCB)