scholarly journals High-Speed Diagnostics in a Natural Gas–Air Rotating Detonation Engine

2020 ◽  
Vol 36 (4) ◽  
pp. 498-507 ◽  
Author(s):  
Christopher L. Journell ◽  
Rohan M. Gejji ◽  
Ian V. Walters ◽  
Aaron I. Lemcherfi ◽  
Carson D. Slabaugh ◽  
...  
Keyword(s):  
Natural Gas ◽  
High Speed ◽  
Rotating Detonation Engine ◽  
Detonation Engine ◽  
Rotating Detonation

scholarly journals Numerical Analysis of Detonability Assessment in a Natural Gas-Air Fueled Rotating Detonation Engine

2019 ◽  
Author(s):  
Pankaj Saha ◽  
Peter Strakey ◽  
Donald Ferguson ◽  
Arnab Roy
Keyword(s):  
Natural Gas ◽  
Detonation Wave ◽  
Hydrogen Fuel ◽  
Air Breathing ◽  
Wave Characteristics ◽  
Fuel Blends ◽  
Rotating Detonation Engine ◽  
Continuous Detonation ◽  
Detonation Engine ◽  
Rotating Detonation

Abstract Rotating Detonation Engines (RDE) offer an alternative combustion strategy to replace conventional constant pressure combustion with a process that could produce a pressure gain without the use of a mechanical compressor. Recent numerical and experimental publications that consider air as the oxidizer have primarily focused on the ability of these annular combustors to sustain a stable continuous detonation wave when fueled by hydrogen. However, for this to be a viable consideration for the land-based power generation it is necessary to explore the ability to detonate natural gas and air within the confines of the annular geometry of an RDE. Previous studies on confined detonations have expressed the importance of permitting detonation cells to fully form within the combustor in order to achieve stability. This poses a challenge for natural gas–air fueled processes as their detonation cell size can be quite large even at moderate pressures. Despite the practical importance, only a few studies are available on natural gas detonations for air-breathing RDE applications. Moreover, the extreme thermodynamic condition (high temperature inside the combustor) allows limited accessibility inside the combustor for detailed experimental instrumentations, providing mostly single-point data. Recent experimental studies at the National Energy Technology Laboratory (NETL) have reported detonation failure at higher methane concentration in an air-breathing RDE fueled by natural gas-hydrogen fuel blends. This encourages to perform a detailed numerical investigation on the wave characteristics of detonation in a natural gas-air fueled RDE to understand the various aspects of instability associated with the natural gas-air detonation. This study is a numerical consideration of a methane-air fueled RDE with varying operating conditions to ascertain the ability to achieve a stable, continuous detonation wave. The simulations have been performed in a 2D unwrapped RDE geometry using the open-source CFD library “OpenFOAM” employing an unsteady pressure-based compressible reactive flow solver with a k–ε turbulence model in a structured rectangular grid system. Both reduced and detailed chemical kinetic models have been used to assess the effect of the chemistry on the detonation wave characteristics and the underlying flow features. A systematic grid sensitivity study has been conducted with various grid sizes to quantify the weakly stable overdriven detonation on a coarse mesh and oscillating features at fine mesh resolutions. The main focus of the current study is to investigate the effects of operating injection pressure on detonation wave characteristics of an air-breathing Rotating Detonation Engine (RDE) fueled with natural gas-hydrogen fuel blends. Wave speeds, peak pressures and temperatures, and dominant frequencies have been computed from the time histories. The flow structures were then visualized using 2D contours of temperature and species concentration.

scholarly journals Performance Characterization of a Natural Gas–Air Rotating Detonation Engine

2020 ◽  
pp. 1-13
Author(s):  
Ian V. Walters ◽  
Aaron Lemcherfi ◽  
Rohan M. Gejji ◽  
Stephen D. Heister ◽  
Carson D. Slabaugh
Keyword(s):  
Natural Gas ◽  
Performance Characterization ◽  
Rotating Detonation Engine ◽  
Detonation Engine ◽  
Rotating Detonation

scholarly journals Parametric Survey of a Natural Gas-Air Rotating Detonation Engine at Elevated Pressure

2019 ◽  
Author(s):  
Ian V. Walters ◽  
Christopher L. Journell ◽  
Aaron Lemcherfi ◽  
Rohan Gejji ◽  
Stephen D. Heister ◽  
...  
Keyword(s):  
Natural Gas ◽  
Elevated Pressure ◽  
Rotating Detonation Engine ◽  
Detonation Engine ◽  
Rotating Detonation

scholarly journals Operability of a Natural Gas–Air Rotating Detonation Engine

2020 ◽  
Vol 36 (3) ◽  
pp. 453-464 ◽  
Author(s):  
Ian V. Walters ◽  
Christopher L. Journell ◽  
Aaron Lemcherfi ◽  
Rohan M. Gejji ◽  
Stephen D. Heister ◽  
...  
Keyword(s):  
Natural Gas ◽  
Rotating Detonation Engine ◽  
Detonation Engine ◽  
Rotating Detonation

Multiphase Rotating Detonation Engine

2020 ◽  
Author(s):  
Ian Dunn ◽  
Kareem Ahmed
Keyword(s):  
Detonation Wave ◽  
High Speed ◽  
Fourier Transforms ◽  
Operational Parameters ◽  
Discrete Fourier Transforms ◽  
Rotating Detonation Engine ◽  
Coal Particles ◽  
Detonation Engine ◽  
Rotating Detonation ◽  
Carbon Concentrations

Abstract The first experimental evidence of a solid-gas multiphase rotating detonation engine. Coal particles, carbon black with a volatility of 1% and a carbon concentration of 99%, were detonated successfully over many operational parameters. These operational parameters surrounding the various points of investigation are shown in multiple 2-D slices as well as plotted in one 3-D graph to show the effects of varying carbon concentrations. These parameters include: variation in total mass flux injected into the annulus ranging from (≅120–270 kg/(s*m2), variation in hydrogen-air equivalence ratio (0.65–1.0), and finally variation in total concentrations of carbon (0–42.5%). High-speed backend imaging allowed for the analysis of the detonation wave dynamics, where detonation velocities were deduced using Discrete Fourier Transforms. By varying the parameters mentioned above, detonation velocities experienced in the detonation channel allowed for an introduction of an optimal operational point. When carbon was injected into very lean hydrogen-air conditions, the detonation was over-driven, causing fluctuations in the detonation velocities upwards of ∼100 m/s. As carbon concentrations increased further, detonation wave velocities relative to Chapman-Jouguet detonation velocities decreased.

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