**Author details**

with Realizable k-ε as a turbulence closure model. The eddy dissipation model is

The passive control added to the basic of the burner is based on the inclined of side oxygen jets towards the central natural gas jet in burner with three separated jets. From ϴ = 0° to inclined state ϴ = 30°, the jets fusion point becomes closer the burner as well as the dynamic field changes. The result shows that the inclination of the jets affects significantly the flow field and consequently the flame behaviour. The effect of equivalence ratio and hydrogen on characteristics of a nonpremixed oxy-methane flame from a burner with separated jets is studied in this document. The velocity fields with different equivalence ratio (0.7, 0.8 and 1) are presented. Near the burner a decrease in the equivalence ratio increases the injection velocity of the lateral jet and keeps a constant velocity in the central jet. For the turbulence intensity, near and far from the burner, an increase in the turbulence intensity is observed in the two layers of internal mixtures, this makes it possible to improve the mixing and increase the stability of the flame. Thus, there is an increase in the adiabatic temperature of the flame, which promotes heat transfer and

The use of hydrogen solves instability problems of the flame that are related to lean combustion, due to the high diffusivity and reactivity of hydrogen in combustion. The results showed that the addition of hydrogen increased the flame velocity and the temperature while reducing CO2 and CO emissions due to the reduction of

applied to take into account the turbulence-reaction interactions.

*Numerical and Experimental Studies on Combustion Engines and Vehicles*

improves thermal efficiency.

d Tube internal tube, mm mng mass flow rate, kg.s<sup>1</sup>

S separation distance between the jets, mm

Ung nozzle exit velocity of gas, m.s<sup>1</sup> Uo2 nozzle exit velocity of oxygen, m.s<sup>1</sup> U longitudinal mean velocity, m.s<sup>1</sup> u' longitudinal velocity fluctuation, m.s<sup>1</sup>

V radial mean velocity, m.s<sup>1</sup> v' radial velocity fluctuation, m.s<sup>1</sup> r, x radial and longitudinal coordinate, mm

μ dynamic viscosity, kg.m.s<sup>1</sup>

ρ gas density, kg.m<sup>3</sup> α percentage of hydrogen

Ф transport terms Φ equivalence ratio ΓΦ transport coefficient

ng natural gas jet P thermal power, W Re Reynolds number

the carbon in the fuel.

**Nomenclature**

**Greek symbols**

**28**

Mohamed Ali Mergheni1,2\*, Mohamed Mahdi Belhajbrahim2 , Toufik Boushaki<sup>3</sup> and Jean-Charles Sautet<sup>4</sup>

1 Department of Mechanical Engineering, College of Engineering, King Khalid University, Abha, Saudi Arabia

2 College of Engineering, University of Monastir, Monastir, Tunisia

3 ICARE-CNRS, Avenue de la Recherche Scientifique, University of Orléans, Orléans, France

4 CORIA, CNRS-Université et INSA de Rouen, Saint Etienne du Rouvray, Rouen, France

\*Address all correspondence to: mmerghni@kku.edu.sa

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
