International Journal of Automotive Technology

, Volume 11, Issue 1, pp 111–117 | Cite as

Parametric study of a free piston linear alternator

Article

Abstract

This work presents the modeling and simulation of a novel free piston linear alternator. The modeling consists of two parts, a thermodynamic model and dynamic model, and these are combined and solved by matlab/simulink. The effects of various intake pressures, moving masses, ignition positions, and resistance loads are studied. The simulation results show that the free piston motion is different from that of the traditional internal combustion engine (ICE). The free piston accelerates and decelerates more quickly at the end of the stroke and additionally, the top dead center is free and changes accordingly with the studied parameters. Thus, a high compression ratio can be easily achieved.

Key Words

Free piston Linear alternator Parametric study Matlab/Simulink 

Nomenclature

Q

heat transfer [J]

ht

enthalpy flow [J/kg]

U

internal energy [J]

δm

micro-unit mass [kg]

δWi

output work [J]

P

cylinder pressure [Pa]

V

cylinder volume [m3]

S

piston cross-sectional area [m2]

cv

specific heat at constant volume [J/kg·K]

Rg

gas constant [J/kg·K]

T

temperature [K]

Hu

lower heating value of the fuel [kJ/kg]

Gb

fuel mass [kg]

χ

mass fraction burned [%]

tz

combustion duration [s]

n

fuel quality

h

heat transfer coefficient [kW/m2·K]

A

heat transfer areas [m2]

νm

piston mean velocity [m/s]

Fmag

thrust force [N]

Kf

thrust constant [N/A]

f

frictional force; [N]

a

piston acceleration [m/s2]

φ

magnetic flux [Wb]

x

piston displacement [m]

ɛ

actual back electromotive force (EMF) [V]

i

stator current [A]

r

stator resistance [Ω]

L

stator inductance [H]

R

external resistance load [Ω]

N

number of windings

d/dt

full derivation with respect to time

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References

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Copyright information

© The Korean Society of Automotive Engineers and Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  1. 1.Key Laboratory for Power Machinery and Engineering of Ministry of EducationShanghai Jiaotong UniversityShanghaiChina

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