Experimental Study on the Production of CO-NO-HC Emissions in the Radial Swirling Flow Combustion System


  • Mohamad Shaiful Ashrul Ishak School of Manufacturing Engineering, Universiti Malaysia Perlis, P.O. Box 77, Pejabat Pos Besar, 01000 Kangar, Perlis, Malaysia
  • Mohammad Nazri Mohd Jaafar Department of Aeronautics, Automotive & Ocean Engineering, Faculty of Mechanical Engineering,Universiti Teknologi Malaysia, 81310 UTM, Johor, Malaysia




Combustion, air swirler, swirl strength, flame stabilizing, CO-NO-HC emission


The main purpose of this paper is to evaluate the production of CO-NO-HC emissions while varying the swirl angle of curve vane radial swirler. Air swirler adds sufficient swirling to the inlet flow to generate central recirculation region (CRZ) which is necessary for flame stability and fuel air mixing enhancement. Therefore designing an appropriate air swirler is a challenge to produce stable, efficient and low emission combustion inside a burner system. Four radial curve vane swirlers with 30o, 40o, 50o and 60o vane angle corresponding to swirl number of 0.366, 0.630, 0.978 and 1.427 respectively were used in this analysis to show the effect of vane angle on emission production at end of combustion chamber. Pollutant NO reduction of more than 10 percent was obtained for the swirl number of 1.427 compared to 0.366. CO emissions were reduced by 20 percent, 25 percent and 38 percent reduction in carbon monoxide (CO) emission for swirl number of 0.630, 0.978 and 1.427 compared to swirl number of 0.366 respectively. Meanwhile, there was a small decrease in unburned HC emissions when increasing the swirl number for the whole range of equivalence ratios.  Results show that the swirling action is augmented with the increase in the vane angle, which leads to better performance of CO-NO-HC emission production inside liquid fuel burner system.


Jaafar, M. N. M., Ishak, M. S. A., Saharin, S. 2010. Removal of NOx and CO from a Burner System. Environmental Science and Technology. 44 (8): 3111–3115.

Gupta, A. K., Lilley, D. G. and Syred, N. 1984. Swirl Flows. Abacus Press, Tunbridge Wells, England.

Sloan, D. G., Smith, P. J. and Smoot, L. D. 1986. Modelling of Swirl in Turbulent Flow System. Prog. Energy Combust. Sci. 12: 163–250.

Lefebvre, A. H. 1983. Gas Turbine Combustion. First edition. Hemisphere Publishing Corporation.

Mellor, A. M. 1990. Design of Modern Gas Turbine Combustor. Academic Press.

Mohd Jaafar, M. N., Eldrainy, Y. A., Ahmad, M. F. 2009. Investigation of Radial Swirler Effect on Flow Pattern inside Gas Turbine Combustor. Modern Appl. Sci. 3(5): 21–30.

Yehia, A. E., Hossam, S. A., Khalid, M. S., Mohd Jaafar, M. N. 2010. A Multiple Inlet Swirler for Gas Turbine Combustors. Int. J. Mechanical Syst. Sci. Eng. 2(2): 106–109.

Beer, J. M., Chigier, N. A. 1972. Combustion Aerodynamics. Applied Science Publishers Ltd.

Spiers, H. M. 1977. Technical Data on Fuel. 7th ed. The British National Committee, World Power Conference, London.

British Standard-BS845. 1987. Methods for Assessing Thermal Performance of Boilers for Steam, Hot Water and High Temperature Heat Transfer Fluids, Comprehensive Procedure. British Standard Institution. United Kingdom.

Gupta, A. K., Lewis, M. J., Qi, S. 1998. Effect of Swirl on Combustion Characteristics of Premixed Flames. J. Eng. Gas Turbine and Power. Trans, ASME. 120: 488–494.




How to Cite

Ashrul Ishak, M. S., & Mohd Jaafar, M. N. (2014). Experimental Study on the Production of CO-NO-HC Emissions in the Radial Swirling Flow Combustion System. Jurnal Teknologi, 69(2). https://doi.org/10.11113/jt.v69.3104