**6. References**

Bejan, A. (1982). Entropy Generation through Heat and Fluid Flow. *Wiley,*New York.

Bejan, A. (1988). Advanced Engineering Thermodynamics. *Wiley,* New York.


**10** 

*China* 

**Dimensionless Parametric Analysis of Spark** 

The decreasing crude oil sources, the increasing concern about greenhouse gas pollution, and the strict emission standards force researchers into never-ending effort to design less polluting and more fuel efficient vehicles. Free-piston linear alternator (FPLA) which is a free-piston engine coupled to a linear alternator, converting piston's kinetic energy into electricity directly, has attracted considerable research interests recently by a number of

1. High efficiency. 1) Direct conversion of piston motion into electric energy with shorter energy transferring path. 2) Reduction of friction between piston ring and cylinder wall

2. High power capacity. With a free-piston engine, heavy mechanical components as crankshaft, flywheel and camshaft are eliminated and the generator is integrated into the engine directly. Therefore, the power-train will have fewer components, lower

3. Controllable compression ratio. The stroke and thus the compression ratio can be

4. Multi-fuel feasibility. The variable compression ratio feature provides the opportunity

5. Few moving parts. There is only one major moving part: the piston, connecting rod and translator assembly. As a consequence, the engine requires less lubrication and has less

6. Good transient response. The free-piston engine reaches its operating point almost immediately since it does not have any energy accumulators, such as flywheel [2]. In the recent two decades, some literatures have already been published about the design and numerical simulation of FPLA. Martin Goertz and Lixin Peng evaluated several feasible hybrid power-train concepts and the results indicated that free-piston linear generator was one of the most promising candidates of the future power-train configuration [3]. West Virginia University had already demonstrated stable operation of a spark ignited FPLA prototype with bore of 36.5mm, maximum possible stroke of 50mm and 316W output power was produced at 79V working at full load [4]. Ehab Shoukry did some research about parametric study of a two-stroke direct injection linear engine using zero dimensional single zone models [5].The European Union has been doing a subject of

research groups worldwide due to its potential advantages listed bellow:

due to the elimination of the dynamic piston side forces.

dynamically controlled through the electrical load.

for the engine to be operated with wide range of fuels [1].

weight and also occupies less space.

**1. Introduction** 

friction wear.

**Ignited Free-Piston Linear Alternator** 

Jinlong Mao, Zhengxing Zuo and Huihua Feng

*School of Mechanical Engineering, Beijing Institute of Technology, Beijing,* 

Jordan, D.P. (1997). Macroscopic Thermodynamics. Part 9: Methodology, *Pergamon.* 

