Computational Analysis of Reacting Flows in Afterburner

Abstract

Gas turbine afterburner is used during take-off, combat, maneuvers, and emergencies when the aircraft engine needs more thrust than normal. A 60° sector full-scaled afterburner, with extended domain of three times the nozzle diameter in the axial direction and two times the nozzle diameter in the radial direction, is modeled. The numerical calculations are performed using SIMPLE algorithm and k–ε model has been used for turbulence. Kerosene (C₁₂H₂₃) is taken as fuel and virtual injectors are specified for fuel injection. Energy equation and species transport with the Discrete Phase model is selected for computations. Maximum density of 1.25 kg/m³ is observed and the density of the fluid reduced to 0.2 kg/m³ at the exit of nozzle after combustion. The desired Mach number of 1.1 could be observed at the exit of the nozzle. The CO₂ mass fraction increased from 0 to 0.075 whereas the O₂ mass fraction decreased from 0.23 to 0.145 from the inlet to the exit of afterburner. The maximum temperature of 2500 K is observed radially at 0.2 m, from the center of the afterburner and axially at a distance of 0.9 m of afterburner. The obtained results are validated with published experimental and computational fluid dynamics results.

Acknowledgements

The authors are greatly indebted to Commandant and Principal of Indian Naval Academy Ezhimala, India, for their support to conduct this research work. The author is also indebted to the guide, faculty and fellow research scholars at National Institute to Technology Calicut, India for their constant support and encouragement.

Additional information

Notes on contributors

Gurrala Srinivasa Rao

Gurrala Srinivasa Rao completed his M. Tech. (Turbomachines) from SVNIT Surat. During this period, he has done his research in the area of stability analysis of Newtonian and non-Newtonian fluids. He is presently working as Associate Professor in Indian Naval Academy, Ezhimala and pursuing his Ph.D. from National Institute of Technology Calicut. He is the Head of Department (Thermal and Fluid Engineering) and continuing research in the area of flame acoustic interaction applicable to gas turbine combustion instabilities. The area of his research includes analytical, numerical and computational analysis of the fluid flow in addition to predicting the instabilities using acoustic analysis.

Andavan Shaija

Andavan Shaija completed her M.Tech. in Thermal Sciences and Engineering from IIT Bombay and Ph.D. from Indian Institute of Science Bangalore in the area of natural convection and surface radiation in annuli. Presently she is working as Professor in the Department of Mechanical Engineering, National Institute of Technology, Calicut, India. Her present area of research includes biofuels and gasification including the study of instabilities in gas turbine afterburners.