Mathematical Problems in Engineering
Volume 2011 (2011), Article ID 861436, 14 pages
http://dx.doi.org/10.1155/2011/861436
Research Article

Characterization of Periodic, Quasiperiodic, and Chaotic States in Nonpremixed Biodiesel/Air Jet Flames

Jianxin Xu,1 Hua Wang,1 and Hui Fang2

1Engineering Research Center of Metallurgical Energy Conservation and Emission Reduction, Ministry of Education, Kunming University of Science and Technology, Yunnan 65009, China
2Department of Applied Mathematics, Kunming University of Science and Technology, Yunnan 650093, China

Received 8 April 2011; Revised 31 July 2011; Accepted 22 August 2011

Academic Editor: Christos H. Skiadas

Copyright © 2011 Jianxin Xu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Characterization for nonpremixed biodiesel/air jet flames instability is investigated by the 0-1 test for chaos and recurrence plots. Test conditions involve biodiesel from Jatropha curcas. L-fueled flames have inlet oil pressure of 0.2–0.6 MPa, fuel flow rates (Q1) of 15–30 kg/h, and combustion air flow rate (Q2) of 150–750 m3/h. This method is based on image analysis and nonlinear dynamics. Structures of flame are analyzed using an image analysis technique to extract position series which are representative of the relative change in temperature of combustion chamber. Compared with the method of maximum Lyapunov exponent, the 0-1 test succeeds in detecting the presence of regular and chaotic components in flame position series. Periodic and quasiperiodic characteristics are obtained by the Poincaré sections. A common characteristic of regular nonpremixed flame tip position series is detected by recurrence plots. Experimental results show that these flame oscillations follow a route to chaos via periodic and quasiperiodic states.