**4. Conclusion**

82 Fuel Injection in Automotive Engineering

[O],[N2]–molar concentration of O-atoms and N2-molecules inside the reaction zone

It proves that the formation rate is controlled by the first Zeldovich reaction. Atoms of oxygen come mainly from dissociation process O2 ↔ 2 O, and their concentration can be

O–equilibrium constant of oxygen dissociation reaction referred to the concentration

[O],[O2]–molar concentration of O-atoms and O2-molecules inside the reaction zone

Finally, the NO formation rate formula (35) takes a following shape (all denotations are as

NO 2 2

<sup>1</sup> 2 [O ] [N ] *dn <sup>c</sup> k K*

The same formula can express a mass flux of NO in kilograms, so as to be used directly in

NO NO 2 2

*dM V <sup>c</sup> k K d n*

7

38000 m 7,6 10 exp mole s

8 2

*T*

*T T T*

O 3 10 mole

 

*RT*

<sup>12954</sup> 5 0,310805 ln( ) 1,07083 0,738336 10 0,344645 10

*T* 

4

µ NO–molar mass of nitric oxide [g/mole]; µ NO = 30.0061,

1

*k*

*c K*

1 1

1O 2 2

1 1

1O 2 2

O and *k*1 can be gathered from the bibliography sources (Heywood, 1988;

3

m

<sup>μ</sup> 2 [O ] [N ] <sup>6000</sup>

*V dt* (37)

(38)

(39)

(40)

1 2

O 2 [O] [O ] *<sup>c</sup> K* (36)

[mole/m3].

where:

[mole/m3],

[mole/m3].

where:

The constants *Kc*

same as above):

the model differential equation system:

n–engine crankshaft speed [rev/min],

–remaining denotations are as same as above.

Rychter & Teodorczyk, 1990), and are equal to:

Kc

calculated as follows:

The mathematical model of combustion that is presented in brief in this chapter consists of a lot of phenomena. Here, the most important like the energy conversion, fuel injection and NOX formation are presented. Many of physical and chemical events occurred in the actual engine have been omitted in the model or considered in a reduced form. It is because of impossibility in their exact mathematical representation. Surely, it influences model accuracy, but can be partially compensated by pre-calculation parametric estimation process. This way of model validation shows the disadvantage, i.e. it has to be anew performed for each engine taken under simulation. Nevertheless, the presented model can be a valuable research tool to be used for extensive studies on combustion in all types of stratified charge engines.
