scholarly journals Combustion Characteristics in Rotating Detonation Engines

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Yuhui Wang ◽  
Wenyou Qiao ◽  
JialingLe
Keyword(s):  
Detonation Wave ◽  
Flow Rate ◽  
Detonation Waves ◽  
Outer Diameter ◽  
Combustion Mode ◽  
Hydrogen Flow ◽  
Pulsed Detonation ◽  
Rotating Detonation Engine ◽  
Rotating Detonation Engines ◽  
Rotating Detonation

A lot of studies on rotating detonation engines have been carried out due to the higher thermal efficiency. However, the number, rotating directions, and intensities of rotating detonation waves are changeful when the flow rate, equivalence ratio, inflow conditions, and engine schemes vary. The present experimental results showed that the combustion mode of a rotating detonation engine was influenced by the combustor scheme. The annular detonation channel had an outer diameter of 100 mm and an inner diameter of 80 mm. Air and hydrogen were injected into the combustor from 60 cylindrical orifices in a diameter of 2 mm and a circular channel with a width of 2 mm, respectively. When the air mass flow rate was increased by keeping hydrogen flow rate constant, the combustion mode varied. Deflagration and diffusive combustion, multiple counterrotating detonation waves, longitudinal pulsed detonation, and a single rotating detonation wave occurred. Both longitudinal pulsed detonation and a single rotating detonation wave occurred at different times in the same operation. They could change between each other, and the evolution direction depended on the air flow rate. The operations with a single rotating detonation wave occurred at equivalence ratios lower than 0.60, which was helpful for the engine cooling and infrared stealth. The generation mechanism of longitudinal pulsed detonation is developed.

HIGH-SPEED IMAGING FOR AN OPTICALLY ACCESSIBLE ROTATING DETONATION ENGINE

2020 ◽  
Author(s):  
Yuhui Wang ◽  
◽  
Jialing Le ◽  
Keyword(s):  
Low Temperature ◽  
Flow Rate ◽  
High Speed ◽  
Equivalence Ratio ◽  
Air Flow ◽  
Detonation Waves ◽  
Outer Diameter ◽  
Air Flow Rate ◽  
High Speed Imaging ◽  
Rotating Detonation

Nonpremixed rotating detonation waves (RDWs) for ethylene or hydrogen and air sources at room temperatures 283-284 K were obtained in the same hollow combustor. The combustor was optically accessible by embedded a piece of quartz glass in the combustor wall. The hollow combustor channel here had an outer diameter 100 mm. Fuel and air were injected into the combustor from 150 cylindrical orifices of a diameter 0.8 mm axially and a circular channel with a width 1 mm radially, respectively. The detonation speeds for ethylene and air were 1562 or 1389 m/s for the air flow rate 642.35 g/s at an equivalence ratio 0.78. The detonation speed for hydrogen and air were 2013 m/s for the air flow rate 327.73 g/s at an equivalence ratio 1.24. Hydrogen operation was more stable than ethylene operation in the condition of low temperature gas sources. High-speed images showed RDW structures were changeful and unstable. Low-temperature regions could intrude into and break the detonation wave.

Critical condition of inner cylinder radius for sustaining rotating detonation waves in rotating detonation engine thruster

2019 ◽  
Vol 37 (3) ◽  
pp. 3461-3469 ◽  
Author(s):  
Akira Kawasaki ◽  
Tomoya Inakawa ◽  
Jiro Kasahara ◽  
Keisuke Goto ◽  
Ken Matsuoka ◽  
...  
Keyword(s):  
Critical Condition ◽  
Detonation Waves ◽  
Cylinder Radius ◽  
Rotating Detonation Engine ◽  
Detonation Engine ◽  
Rotating Detonation

The effect of the throat width of plug nozzles on the combustion mode in rotating detonation engines

Shock Waves ◽  
2018 ◽  
Vol 29 (4) ◽  
pp. 471-485 ◽  
Author(s):  
Y. Wang ◽  
J. Le ◽  
C. Wang ◽  
Y. Zheng ◽  
S. Huang
Keyword(s):  
Combustion Mode ◽  
Throat Width ◽  
Plug Nozzles ◽  
Rotating Detonation Engines ◽  
Rotating Detonation

Evidence of Carbon Driven Detonation Waves within a Rotating Detonation Engine

2021 ◽  
Author(s):  
Ian B. Dunn ◽  
Vidhan Malik ◽  
Kareem A. Ahmed ◽  
Marc Salvadori ◽  
Suresh Menon
Keyword(s):  
Detonation Waves ◽  
Rotating Detonation Engine ◽  
Detonation Engine ◽  
Rotating Detonation

Application of a Convolutional Neural Network for Wave Mode Identification in a Rotating Detonation Combustor Using High-Speed Imaging

2020 ◽  
Author(s):  
Kristyn B. Johnson ◽  
Donald H. Ferguson ◽  
Robert S. Tempke ◽  
Andrew C. Nix
Keyword(s):  
Neural Network ◽  
Detonation Wave ◽  
High Speed ◽  
Wave Mode ◽  
Classification Performance ◽  
Detonation Waves ◽  
Single Image ◽  
High Speed Imaging ◽  
Mode Identification ◽  
Rotating Detonation

Abstract Utilizing a neural network, individual down-axis images of combustion waves in a Rotating Detonation Engine (RDE) can be classified according to the number of detonation waves present and their directional behavior. While the ability to identify the number of waves present within individual images might be intuitive, the further classification of wave rotational direction is a result of the detonation wave’s profile, which suggests its angular direction of movement. The application of deep learning is highly adaptive and therefore can be trained for a variety of image collection methods across RDE study platforms. In this study, a supervised approach is employed where a series of manually classified images is provided to a neural network for the purpose of optimizing the classification performance of the network. These images, referred to as the training set, are individually labeled as one of ten modes present in an experimental RDE. Possible classifications include deflagration, clockwise and counterclockwise variants of co-rotational detonation waves with quantities ranging from one to three waves, as well as single, double and triple counter-rotating detonation waves. After training the network, a second set of manually classified images, referred to as the validation set, is used to evaluate the performance of the model. The ability to predict the detonation wave mode in a single image using a trained neural network substantially reduces computational complexity by circumnavigating the need to evaluate the temporal behavior of individual pixels throughout time. Results suggest that while image quality is critical, it is possible to accurately identify the modal behavior of the detonation wave based on only a single image rather than a sequence of images or signal processing. Successful identification of wave behavior using image classification serves as a stepping stone for further machine learning integration in RDE research and comprehensive real-time diagnostics.

scholarly journals Analysis of the Detonation Wave Structure in a Linearized Rotating Detonation Engine

AIAA Journal ◽  
2020 ◽  
Vol 58 (12) ◽  
pp. 5063-5077 ◽  
Author(s):  
Supraj Prakash ◽  
Romain Fiévet ◽  
Venkat Raman ◽  
Jason Burr ◽  
Kenneth H. Yu
Keyword(s):  
Detonation Wave ◽  
Wave Structure ◽  
Rotating Detonation Engine ◽  
Detonation Engine ◽  
Rotating Detonation
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