Klausur

B = quantity of fuel in liter

L = distance in 100 km

—> Ergebniss ist l pro 100 km

Vh = piston displacement = Hubraum

Vc = compression volume

b = track width (Spurbreite=

R = curve radius

hs= height of center of gravity

• No engine speed gap during start up, high torque available from start

• Better and more suitable torque characteristics

• High efficiency of e motor

• energy recuperation possible

• Storage proble of electrical energy

• overall efficiency of rive system with regard to energy production and storage is low

• Torque and speed converters transform the speed and torque characteristics of an engine into a different speed and torque characteristics. Torque & speed converters are for example clutches and gear boxes.

• Speed converter = clutch —> Ma=Me but na ≠ ne

• max speed

• max gradient

• max acceleration

• which gear can be used at a certain speed and traction force atr different acceleration or gradient operations

• The driving performance results from running resistances and the limitations of the drive train on high friction surface

• Examples - Top speed on level road, climbing ability, acceleration ability

It shows the fuel consumption at a const. speed, road gradient and acceleration

• small rolling resistance

• mass must be small

• product of cw * A must be small (Air resistance)

• The mean efficiency of the combustion engine must be high

• The mean efficiency of the torque and speed converter must be high

• NEDC: New European Driving Cycle

• WLTC / WLTP: Worldwide Harmonized light duty Vehicle test Procedure

• lambda < 1: highj CO + HC emissions

• lambda > 1: high NOx emissions

• Chargign efficiency is the ratio of the fresh gas mass actually remaining in the cylinder to the theoretically maximum filling

• Max for suction engines 0,6 - 0,9 with supercharging > 1

• Dynamic supercharging using vibrations of the air column

• Mechanical supercharging - compressor driven by crankshaft

• Exhaust gas turbocharging - compressor driven by exhaust gas

• External supercharging - compressor driven by electric motor

• increased power and torque

• reduced fuel consumption

• lower exhaust emissions

• means a lamda of 1

• the exact ammount of oxygen is supplied to the combustion as requiered

• less emissions of NOx HC and CO

• Indicated power only contains the thermodynamic losses and the losses from the carge cycle. The friction losses are not included. Measured by the pressure in the cylinder

• Effective power contains all losses of the engine. Meassured of the crankshaft

• The thermodynamic reference cylce shows an ideal cornot cycle.

• You can read the :

  • added and discharged heat

  • the work done of the process

  • the minimal and maximal temperature

  
  

• increase the ammount of air in the combustion chamber

• increase the ammount of fuel

• Because of the high temperatures at lean combustion

selfignition

• too expensive and heavy for small cars

• needs minimum temperature

• regular refilling of AdBlue at petrol stations

• Fuel composition: Diesel fuel contains higher levels of sulfur and nitrogen compounds than gasoline, which can poison the catalytic converter and reduce its effectiveness.

• Combustion process: The combustion process in a diesel engine is different than that of a gasoline engine, and the exhaust gases that are produced are also different. The high temperatures and pressures in a diesel engine can cause the catalytic converter to degrade more quickly.

• NOx emissions: NOx emissions from diesel engines are typically much higher than those from gasoline engines, and the 3-way catalytic converter is not as effective at reducing NOx as it is at reducing CO and HC.

• emit fewer harmfull pollutants

• emit less CO2 or other greenhouse gases

• Less use of fossil or nuclear fuel for operation

• Less harmful noise

• change of transport mode to public transport, bike or walking

• change use of car. E.g more effective navigationm or more passengers per journey

• reduction of running resistrances

• efficient convbentional drives

• alternative fuels

• electric and hybrid drives

• vehicle acceleration increases kinetic energy of vehicle —> can be partially recuperated

• vehicle climbing uphill increases potential energy —> can be partially recuperated

• can be burned in conventional ICE

• CO2 reduction for existing car fleet

• worldwide infrastructure can be used

• overall efficiency from electricity to fuel between 45-60%

• high cost

• availability of CO2

• locally zero pollutants and CO2 emissions

• recuperation possible

• low noise

• convincing driving performance

• increased driving comfort

• Regarding CO2 emissions only advantageous if electrical power used from renewable sources

• Reduced range with todays battery technologies

• Higher costs

Advantages:

• summation of power/ torque possible

• only one electrical machine

• better efficiency

Disadvantages:

• more constaints for packaging

• simultaneoues charging and electric driving not possible

Advantages:

• free choice of packaging

• combustion engine runs at ideal operation point

Disadvantages:

• less overall eficiency due to multiple energy convbersions

• 2 electrical machines —> higer costs

Pro:

• advantages like BEV

• only small ICE for range extension

• free choise of packaging

• combustion engine runs at ideal operation point

Con:

• additional cost and weight for range extender

• 2 electrical machines

• electric traction motor

• HV Battery

• Power electronics (DC/DC converter)

• ECU

• charging device

wheel slip angle (alpha)

Driving limits:

• are given by physical laws

• Max cornering speed, max climbing performance at low friction

Driving behavior:

• Driving behaviour is the reaction of the vehicle to the driver’s actions and disturbances during movement, described by the movement parameters. Good driving behaviour is the possibility to comply exactly with the desired course in terms of the vehicle guidance function and thus is an essential component of the control performance of the overall system.

• The most important aspect for evaluation and review of driving behaviour is the contribution to the prevention of traffic accidents. Good driving behaviour means that the risk of accidents for drivers and vehicles on the road is reduced to a minimum.

  
  

• Assesment of the overall systems together with the driver. given is for example course of the road and maneuver

• close to reality

• Disadvantage: subjective

• Driver's influence is eliminated by steering and braking machines as far as possible.

• Goal is to study the vehicle response to operations and disturbances, from which the vehcicle course results.

• Advantage: good reproducibility, vehicle influence is visible

• Disadvantage: limited to a small area of driving behavior

1. v max eintragen

2. Z berechnen = ende der Zugkrafthyperbel

3. Zmax berechnen

4. Punkt für adhesion limit ausrechnen

5. mit gegebenen Punkten DIagramm erstellen