**6. Conclusion**

298 Thermodynamics – Interaction Studies – Solids, Liquids and Gases

mean piston speed

cylinder

*dt* velocity

acceleration

2 2 *d x dt*

The in-cylinder pressure curves with different ignition compression ratio while *Leff*\*=0.6765 are shown in Fig.23. It is clear that smaller ignition compression ratio or bigger ignition advance leads to higher peak pressure which is in agreement with the

effectively compressed volume of the

*a* combustion constant *R* air gas constant *A* top area of the piston *RL* load resistance

*b* combustion form factor *t* time

*h* heat transfer coefficient *U*

*<sup>H</sup>*length of the coils cutting magnetic lines *Veff*

*He* enthalpy output *W* work done *Hi* enthalpy input *We* effective work *iL* current in the load circuit *Wf* frictional work *L* induction *Wi* indicated work

*M* load coefficient *γ* specific heat ratio *MF* mean magneto motive force *ε* compression ratio

*Ncoil* number of turns in the coil *εind* induced voltage

*pR* pressures in the right cylinder *τ* pole pitch *Pe* effective power output *τ<sup>p</sup>* width of PM *Pf* frictional power *η<sup>e</sup>* effective efficiency *Q* energy *η<sup>i</sup>* indicated efficiency

*Qc* heat released in combustion *dx*

(The variable with superscript "\*" is its dimensionless form.)

*Qht* heat transfer

*Qin* total input energy

dimensionless results.

*pL* pressures in the left cylinder *μ<sup>0</sup>* vacuum permeability

*Acyl* heat transfer area *Rs* internal resistance of coils

*B* magnetic induction intensity *t0* time combustion begins *cV* constant volume specific heat *tc* combustion duration *D* cylinder diameter *tign* ignition timing *f* frequency *T* temperature

*Fe* electromagnetic force *T0* scavenge temperature *Ff* friction force *Tw* wall temperature *g* air gap length *U* internal energy

*hm* thickness of the permanent magnet *V* displaced volume of the cylinder

*Hc* magnetic field strength *Vign* volume of the cylinder when ignite

*Ltot* total stroke length *x* displacement of the translator *Leff* effective stroke length *xign* translator ignition position *m* translator mass *xs* half of maximum stroke length *min* mass of the charge *α* opening proportion of throttle

*n* polytrophic exponent *εign* ignition compression ratio

*p* in-cylinder absolute pressure *Φ* flux passing through the coil *p0* scavenge pressure *λ* total flux pass through the coil

**Nomenclature** 

A detailed dimensionless modeling and dimensionless parametric study of spark ignited FPLA was presented to build up a guideline for the design of FPLA prototype with desired operating performances. The parameters of the numerical simulation program were amended by comparing the simulated in-cylinder pressure with experimentally derived data. At last CFD calculation of the combustion process was carried out to verify the effects of translator ignition position with two kinds of typical effective stroke length to bore ratios. According to the dimensionless results, it can be concluded that:

