Numerical Study of Deflagration to Detonation Transition in 2D and Axisymmetric Detonation Tube with Obstacles Using OpenFOAM

2020 ◽  
pp. 807-820
Author(s):  
Udit Vohra ◽  
Rajpreet Singh ◽  
Vinayak Bassi ◽  
T. K. Jindal ◽  
Amarjit Singh
Keyword(s):  
Numerical Study ◽  
Detonation Tube ◽  
Deflagration To Detonation Transition ◽  
Detonation Transition

Experimental investigation on multi-cycle two-phase spiral pulse detonation tube of two configurations

2018 ◽  
Vol 233 (11) ◽  
pp. 4166-4175
Author(s):  
Hua Qiu ◽  
Zheng Su ◽  
Cha Xiong
Keyword(s):  
Pressure Waves ◽  
Propagation Characteristics ◽  
Transient Pressure ◽  
Two Phase ◽  
Pulse Detonation ◽  
Compression Waves ◽  
Detonation Tube ◽  
Deflagration To Detonation Transition ◽  
Pulsed Detonation ◽  
Detonation Transition

The spiral tube structure is an effective method to shorten the axial length of the pulse detonation chamber. In this article, spiral pulsed detonation tube with two kinds of spiral configuration was experimentally investigated. Liquid gasoline and air were used as fuel and oxidant, respectively, and equivalence ratios were controlled to about 1.0. Based on the transient pressure along the tube, the propagation characteristics of the pressure waves in the multi-cycle spiral pulsed detonation tubes, such as pressure peaks, wave velocities and propagation process, were analyzed. Results showed that propagation of double compression waves was the common feature during the process of deflagration to detonation transition in the presented spiral tubes, and the onset of detonation was initiated by a local explosion in the second compression wave. The deflagration to detonation transition characteristics with detonation initiation and combustion characteristics without initiation in the spiral sections were both related to the dimensionless distance. Propagation characteristics of the pressure waves were influenced by the use of different spiral configuration. And some interesting phenomena were also found.

NUMERICAL SIMULATION OF DEFLAGRATION-TO-DETONATION TRANSITION IN A PULSED DETONATION ENGINE

2020 ◽  
Author(s):  
A. E. Zangiev ◽  
◽  
V. S. Ivanov ◽  
S. M. Frolov ◽  
◽  
...  
Keyword(s):  
Check Valve ◽  
Fuel Mixture ◽  
Minimum Length ◽  
Flame Acceleration ◽  
Pulsed Detonation Engine ◽  
Detonation Tube ◽  
Deflagration To Detonation Transition ◽  
Pulsed Detonation ◽  
Detonation Engine ◽  
Detonation Transition

The air-breathing pulsed detonation engine (PDE) for an aircraft designed for a subsonic flight when operating on the products of pyrolysis of polypropylene was developed using the analytical estimates and parametric multivariant threedimensional (3D) calculations. The PDE consists of an air intake with a check valve, a fuel supply system, a prechamber-jet ignition system, and a combustion chamber with an attached detonation tube. Parametric 3D calculations allowed choosing the best length of the PDE combustor, which provides an efficient mixing of air with fuel, the best way to ignite the mixture (prechamber-jet ignition), the best location of the prechamber, the minimum length of the section with turbulizing obstacles for flame acceleration and deflagration-to-detonation transition (DDT), and the best degree of filling the detonation tube with the fuel mixture to achieve the maximum completeness of combustion.

Computational Study of Deflagration to Detonation Transition in Pulse Detonation Engine Using Shchelkin Spiral

2015 ◽  
Vol 772 ◽  
pp. 136-140 ◽  
Author(s):  
Pinku Debnath ◽  
Krishna Murari Pandey
Keyword(s):  
Combustion Wave ◽  
Computational Study ◽  
Pulse Detonation Engine ◽  
Flame Velocity ◽  
Pulse Detonation ◽  
Detonation Tube ◽  
Deflagration To Detonation Transition ◽  
Contour Plots ◽  
Detonation Engine ◽  
Detonation Transition

Detonation combustion wave is much more energetic combustion process in pulse detonation engine combustion system. Numerous experimental, theoretical and numerical analyses have been studied in pulse detonation engine to implement in practical propulsion system. In this present computational study the simulation was carried out for deflagration flame acceleration and deflagration to detonation transition of hydrogen air combustible mixture inside the detonation tube with and without Shchelkin spiral. A three dimensional computational analysis has been done by finite volume discretization method using ANSYS Fluent 14 CFD commercial software. The LES turbulence model with second order upwind discretization scheme was adopted with standard boundary conditions for unsteady combustion wave simulations. From the computational study it was found that intensity of detonation wave velocity and dynamic pressure is higher near to the boundary of Shchelkin spiral in detonation tube. The contour plots comparisons clearly show that deflagration flame accelerates in detonation tube as present of Shchelkin spiral. The contour plots also suggest that deflagration flame velocity and pressure are less in without Shchelkin spiral in detonation tube. The accelerating detonation waves are approximately near about Chapment-Jouguet values in detonation tube with Shchelkin spiral.

scholarly journals Numerical simulation of the deflagration-to-detonation transition of iso-octane vapor in an obstacle-filled tube

2018 ◽  
Vol 10 (3) ◽  
pp. 244-259 ◽  
Author(s):  
Hu Ma ◽  
Zhenjuan Xia ◽  
Wei Gao ◽  
Changfei Zhuo ◽  
Dong Wang
Keyword(s):  
Activation Energy ◽  
Flame Front ◽  
Total Energy Release ◽  
Exponential Factor ◽  
Transition Processes ◽  
Flame Acceleration ◽  
Detonation Tube ◽  
Deflagration To Detonation Transition ◽  
Detonation Transition ◽  
Total Energy Release Rate

Flame acceleration and deflagration-to-detonation transition of an iso-octane vapor–air mixture in an obstacle-filled detonation tube were simulated by solving Navier–Stokes equations with a single-step reaction mechanism. A variable specific heat ratio was used in these simulations. Detonation cell size was successfully simulated for the iso-octane vapor–air mixture. Two methods for initiating detonation waves were revealed in a detonation tube with obstacles. Pressure and flame parameters, such as the temporal variation of total energy release rate, flame front location, propagation velocity of the flame front, and flame front area, were investigated during the flame acceleration and deflagration-to-detonation transition process. According to the variation of these parameters, flame acceleration and deflagration-to-detonation transition processes could be divided into four stages, i.e. the early stage of flame acceleration, the middle stage of flame acceleration, the end stage of flame acceleration, and the detonation transition stage. The effects of activation energy and pre-exponential factor on deflagration-to-detonation transition processes were examined. The results indicate that the pre-exponential factor and activation energy influence the flame parameters, but not the development law of flame acceleration or deflagration-to-detonation transition processes. For lower reactants activity, detonation wave is easy to fail in couple while bypassing obstacles in the obstacle-filled detonation tube, which causes a large fluctuation in flame propagation velocity and total energy release rate. The length of detonation tube filled by obstacles should not be more than deflagration-to-detonation transition distance. These investigations are conducive to understanding the flame acceleration and deflagration-to-detonation transition and developing detonation combustion chamber of pulse detonation engine.

scholarly journals Experimental research into the influence of two­spark ignition on the deflagration to detonation transition process in a detonation tube

2019 ◽  
Vol 4 (5 (100)) ◽  
pp. 26-31
Author(s):  
Kostyantyn Korytchenko ◽  
Pavel Krivosheyev ◽  
Dmytro Dubinin ◽  
Andrii Lisniak ◽  
Kostiantyn Afanasenko ◽  
...  
Keyword(s):  
Experimental Research ◽  
Transition Process ◽  
Detonation Tube ◽  
Deflagration To Detonation Transition ◽  
Detonation Transition

Cellular Pattern Evolution of Deflagration-to-Detonation Transition in Square Detonation Tube

2011 ◽  
Vol 130-134 ◽  
pp. 3351-3355
Author(s):  
Peng Gang Zhang ◽  
Xiao Min He ◽  
Qian Wang
Keyword(s):  
Experimental Investigation ◽  
Detonation Wave ◽  
Early Stage ◽  
Pressure Transducers ◽  
Entire Process ◽  
Detonation Tube ◽  
Deflagration To Detonation Transition ◽  
Cellular Pattern ◽  
Detonation Transition ◽  
Overdriven Detonation

This paper presents recent results of an experimental investigation on Deflagration to Detonation Transition (DDT) with H2/air and C2H2/air mixtures in 60mm×60mm square detonation tube. The entire process of DDT is demonstrated by cellular patterns and the analysis is mainly based on their evolution.The pressure transducers and ion-probes were utilized to get the pressure and flame history in the tube respectively, and the corresponding cellular patterns are recorded on soot foils along cover board with 60mm×1380mm.Results show that overdriven detonation appears only once and several blast appear in DDT.Cellular patterns show that severaltwistable linesappear at the obstacle exit neighborhood area , while regular cell takes place after the final twistable line.Details of the cellular pattern indicate that from the early stage to the end of regular cell, the detonation wave sequentially experiences impactive area, abundant secondary cells, secondary cells expanding, local explosive, fine secondary cells, regular cell.

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