scholarly journals The effect of wall temperature on three-dimensional rotating detonation wave

2021 ◽  
Vol 1786 (1) ◽  
pp. 012045
Author(s):  
Pengxin Liu ◽  
Chen Li ◽  
Dong Sun ◽  
Qilong Guo ◽  
Wei Zhao
2019 ◽  
Vol 9 (20) ◽  
pp. 4259 ◽  
Author(s):  
Chengwen Sun ◽  
Hongtao Zheng ◽  
Zhiming Li ◽  
Ningbo Zhao ◽  
Lei Qi ◽  
...  

In this study, three-dimensional numerical studies have been performed to investigate the performance of a rotating detonation combustor with a diverging nozzle downstream. The effects of a diverging nozzle on the formation and propagation process of a detonation wave and typical flow field parameters in a rotating detonation combustor are mainly discussed. The results indicate that the diverging nozzle downstream is an important factor affecting the performance and design of a rotating detonation combustor. The diverging nozzle does not affect the formation and propagation process of the rotating detonation wave, while the time of two key wave collisions are delayed during the formation process of the detonation wave. With increases of the diverging angle, the rotating detonation combustor with the diverging nozzle can still maintain a certain pressure gain performance. Both the diverging nozzle and diverging angle have great influence on the flow field parameters of the rotating detonation combustor, including reducing the high pressure and temperature load, making the distribution of the outlet parameters uniform, and changing the local supersonic flow at the outlet. Among them, the outlet static pressure is reduced by up to 88.32%, and the outlet static temperature is reduced by up to 32.12%. This evidently improves the working environment of the combustor while reducing the thermodynamic and aerodynamic loads at the outlet. In particular, the diverging nozzle does not affect the supersonic characteristics of the outlet airflow, and on this basis, the Mach number becomes coincident and enhanced.


2020 ◽  
Vol 45 (53) ◽  
pp. 29546-29559 ◽  
Author(s):  
Pengxin Liu ◽  
Qilong Guo ◽  
Dong Sun ◽  
Chen Li ◽  
Hanxin Zhang

2021 ◽  
Vol 9 ◽  
Author(s):  
Chenyi Su ◽  
Xingqi Xu ◽  
Jinghua Huang ◽  
Bailiang Pan

Abstract Considering the thermodynamical fluid mechanics in the gain medium and laser kinetic processes, a three-dimensional theoretical model of an exciplex-pumped Cs vapor laser with longitudinal and transverse gas flow is established. The slope efficiency of laser calculated by the model shows good agreement with the experimental data. The comprehensive three-dimensional distribution of temperature and particle density of Cs is depicted. The influence of pump intensity, wall temperature, and fluid velocity on the laser output performance is also simulated and analyzed in detail, suggesting that a higher wall temperature can guarantee a higher output laser power while causing a more significant heat accumulation in the cell. Compared with longitudinal gas flow, the transverse flow can improve the output laser power by effectively removing the generated heat accumulation and alleviating the temperature gradient in the cell.


Author(s):  
Arnab Roy ◽  
Donald Ferguson ◽  
Todd Sidwell ◽  
Peter Strakey

Operational characteristics of an air breathing Rotating Detonation Combustor (RDC) fueled by natural gas-hydrogen blends are discussed in this paper. Experiments were performed on a 152 mm diameter uncooled RDC with a combustor to inlet area ratio of 0.2 at elevated inlet temperature and combustor pressure while varying the fuel split between natural gas and hydrogen over a range of equivalence ratios. Experimental data from short-duration (∼6sec) tests are presented with an emphasis on identifying detonability limits and exploring detonation stability with the addition of natural gas. Although the nominal combustor used in this experiment was not specifically designed for natural gas-air mixtures, significant advances in understanding conditions necessary for sustaining a stable, continuous detonation wave in a natural gas-hydrogen blended fuel were achieved. Data from the experimental study suggests that at elevated combustor pressures (2–3bar), only a small amount of natural gas added to the hydrogen is needed to alter the detonation wave operational mode. Additional observations indicate that an increase in air inlet temperature (up to 204°C) at atmospheric conditions significantly affects RDC performance by increasing deflagration losses through an increase in the number of combustion (detonation/Deflagration) regions present in the combustor. At higher backpressure levels the RDC exhibited the ability to achieve stable detonation with increasing concentrations of natural gas (with natural gas / hydrogen-air blend). However, losses tend to increase at intermediate air preheat levels (∼120°C). It was observed that combustor pressure had a first order influence on RDC stability in the presence of natural gas. Combining the results from this limited experimental study with our theoretical understanding of detonation wave fundamentals provides a pathway for developing an advanced combustor capable of replacing conventional constant pressure combustors typical of most power generation processes with one that produces a pressure gain.


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