Numerical simulations on propane/oxygen detonation in a narrow channel using a detailed chemical mechanism: formation an
- PDF / 10,734,139 Bytes
- 16 Pages / 595.276 x 790.866 pts Page_size
- 61 Downloads / 181 Views
ORIGINAL ARTICLE
Numerical simulations on propane/oxygen detonation in a narrow channel using a detailed chemical mechanism: formation and detailed structure of irregular cells N. Takeshima1
· K. Ozawa1 · N. Tsuboi1 · A. K. Hayashi2 · Y. Morii3
Received: 30 November 2019 / Revised: 28 October 2020 / Accepted: 1 November 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract Numerical simulations of two-dimensional inviscid detonations for a stoichiometric propane/oxygen gas mixture are performed using a detailed chemical reaction model. The UC San Diego model which includes 57 chemical species and 268 elementary reactions is mainly used in the present study. It is shown that a grid size of 3 µm can capture important features such as the unburned gas pocket behind the detonation when compared to larger grid sizes. The effects of channel width show that the detonation propagates with the CJ (Chapman–Jouguet) velocity for all cases and for more than 100 times the channel width of 4.5 mm. Increasing the channel width results in an irregular detonation cell structure. A transverse detonation forms with cross-hatching marks on the maximum pressure history. The irregular detonation cell structure forms because both the reduced activation energy and the stability parameter have a value of approximately 10; however, the maximum thermicity in the detonation is one. The free radicals C3 H7 and H2 O2 play an important role in the propane oxidation under the high temperature in the detonation. The maximum concentration exists at a temperature of 2000–3000 K. The fifth-order WCNS (weighted compact nonlinear scheme) scheme can resolve the contact surface and complicated flow structure behind the detonation front compared to the second-order MUSCL (Monotonic Upstream-centered Scheme for Conservation Laws). Keywords Detonation dynamics · Detonation structure · Propane · Detailed chemical reaction · Numerical simulation
1 Introduction Detonation is a supersonic combustion phenomenon where high-pressure and high-temperature reactions are involved. Communicated by G. Ciccarelli. This paper is based on work that was presented at the 25th International Colloquium on the Dynamics of Explosions and Reactive Systems, Beijing, China, July 28–August 2, 2019.
B
N. Tsuboi [email protected]; [email protected] N. Takeshima [email protected]
1
Department of Mechanical and Control Engineering, Kyushu Institute of Technology, Kitakyushu, Fukuoka, Japan
2
Department of Mechanical Engineering, Aoyama Gakuin University, Sagamihara, Kanagawa, Japan
3
Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan
Detonations can seriously damage industrial plants. Explosion accidents related to detonations have been recorded in many different locations [1, 2]. Therefore, in the field of safety engineering, understanding the initiation conditions and propagation limits of detonation is very important. Unstable detonation propagation and its structure are one of the most important topics in
Data Loading...