共查询到20条相似文献,搜索用时 31 毫秒
1.
《International Journal of Hydrogen Energy》2023,48(62):24113-24126
Experimental and dynamic analyses of the deflagration characteristics of laminar premixed syngas-air at different preheating temperatures and with different CO2 volume fractions were carried out in a rectangular half-open pipe. The effects of CO2 concentration and different initial temperatures on the flame structure evolution, flame structure profile and reaction rate of critical radicals, flame propagation speed, overpressure dynamics and hydrodynamic instability of syngas-air mixture were studied. The FFCM-1 mechanism was used to predict the laminar burning velocity of syngas-air under relevant conditions. The results revealed that the addition of CO2 inhibited the flame propagation and reduced the concentration of H, OH and O, thus reduced the laminar burning velocity. The increase in temperature promotes the chemical effect of CO2, and the interaction between the flame front and the pressure wave is more pronounced, prolonging the duration of the " tulip " flame. Adding CO2 reduces the flame front speed and overpressure, decreases the oscillation amplitude in late flame propagation, and inhibits the explosion intensity. Meanwhile, the temperature increase accelerates the flame propagation in the spherical and finger stages, and the maximum flame propagation speed and peak pressure appear earlier. In addition, as CO2 content and temperature rise, flame hydrodynamic instability is difficult to ignore. However, there is a lack of data from studies of syngas deflagration dynamics at higher temperatures and with higher CO2 additions. This suggests a focus on studies at higher temperatures as well as with higher CO2 additions to enable the development of accurate kinetic models for wide range of syngas combustion. Also, the higher the initial temperature, the longer the time required for heating. 相似文献
2.
《International Journal of Hydrogen Energy》2022,47(87):37125-37137
With the industrial application of syngas, the explosion accident caused by it has gradually become a topic of concern for researchers. In this paper, the effects of CO2 addition on the deflagration characteristics of syngas-air premixed mixtures were investigated through experiments and numerical simulations. Experiments were carried out inside a T-pipeline, using a high-speed camera and a pressure sensor to simultaneously record the flame evolution and pressure dynamics during deflagration. Simulations were calculated using the GRI 3.0 mechanism by Chemkin Premix Code. The results show that the addition of CO2 has a certain inhibitory effect on the flame propagation, which can make the finger flame in the vertical pipe evolve into a “tulip” flame. And under the inhibition of CO2, the deflagration overpressure of the mixture is reduced, and the number of H, O, OH radicals is also greatly reduced, and the chemical reaction rate is correspondingly slowed down. 相似文献
3.
In this study, effect of carbon dioxide dilution on explosive behavior of syngas/air mixture was investigated numerically and experimentally. Explosion in a 3-D cylindrical geometry model with dimensions identical to the chamber used in the experiment was simulated using ANSYS Fluent. The simulated results showed that after ignition, the flame front propagated outward spherically until it touched the wall, like the propagating flame observed in the experiment. Both experimental and simulated results presented a same trend of decreasing the maximum explosion pressure and prolonging the explosion time with CO2 dilution. The results showed that for CO2 additions, the maximum explosion pressure decreased linearly and the explosion time increased linearly, while the maximum rate of pressure rise decreased nonlinearly, which can be correlated to an exponential equation. In addition, both results showed a good agreement for syngas/air flame with CO2 addition up to 20% in volume. However, larger discrepancies were observed for higher levels of CO2 dilutions. Of the three diluents tested, carbon dioxide displayed the strongest effect in reducing explosion hazard of syngas/air flame compared to helium and nitrogen. Chemical kinetic analysis results showed that maximum concentration of major radicals and net reaction rates of important reactions drastically decreased with CO2 addition, causing a reduction of laminar flame speed. 相似文献
4.
Minggao Yu Xufeng Yang Kai Zheng Ligang Zheng Xiaoping Wen 《International Journal of Hydrogen Energy》2018,43(29):13676-13686
The propagation behaviour of a deflagration premixed syngas/air flame over a wide range of equivalence ratios is investigated experimentally in a closed rectangular duct using a high-speed camera and pressure transducer. The syngas hydrogen volume fraction, φ, ranges from 0.1 to 0.9. The flame propagation parameters such as flame structure, propagation time, velocity and overpressure are obtained from the experiment. The effects of the equivalence ratio and hydrogen fraction on flame propagation behaviour are examined. The results indicate that the hydrogen fraction in a syngas mixture greatly influences the flame propagation behaviour. When φ, the hydrogen fraction, is ≥0.5, the prominently distorted tulip flame can be formed in all equivalence ratios, and the minimum propagation time can be obtained at an equivalence ratio of 2.0. When φ < 0.5, the tulip flame distortion only occurs in a hydrogen fraction of φ = 0.3 with an equivalence ratio of 1.5 and above. The minimum flame propagation time can be acquired at an equivalence ratio of 1.5. The distortion occurs when the maximum flame propagation velocity is larger than 31.27 m s?1. The observable oscillation and stepped rise in the overpressure trajectory indicate that the pressure wave plays an important role in the syngas/air deflagration. The initial tulip distortion time and the plane flame formation time share the same tendency in all equivalence ratios, and the time interval between them is nearly constant, 4.03 ms. This parameter is important for exploring the quantitative theory or models of distorted tulip flames. 相似文献
5.
The objective of this study is to investigate the impact of syngas composition by varying the H2/CO ratio (1:3, 1:1, and 3:1 by volume), the CO2 dilution (0%–40%), and methane addition (0%–40%) on laminar flame speed. Thus, laminar flame speeds of premixed syngas–air mixtures were measured for different equivalence ratios (0.8–2.2) and inlet temperatures (295–450 K) using the Bunsen-burner method. It was found that laminar flame speed increases with increasing H2/CO ratio, while CO2 dilution or CH4 addition decreased it. The location of the maximum flame speed shifts to richer mixtures with decreasing H2/CO ratio, while it shifts to leaner mixtures with the addition of CH4 due to its inherent slower flame speed. The location of the maximum flame speed is also shifted towards leaner mixtures with the addition of CO2 due to the preponderance of the reduction of the adiabatic flame temperature with increasing dilution. Comparison between experimental and numerical results shows a better agreement using a modified mechanism derived from GRI-Mech 3.0. A correlation, based on the experimental results, is proposed to calculate the laminar flame speed over a wide range of equivalence ratios, inlet temperatures, and fuel content. 相似文献
6.
《International Journal of Hydrogen Energy》2019,44(40):22654-22660
An experimental study of hydrogen/air premixed flame propagation in a closed rectangular channel with the inhibitions (N2 or CO2) was conducted to investigate the inhibiting effect of N2 and CO2 on the flame properties during its propagation. Both Schlieren system and the pressure sensor were used to capture the evolution of flame shape and pressure changes in the channel. It was found that both N2 and CO2 have considerable inhibiting effect on hydrogen/air premixed flames. Compared with N2, CO2 has more prominent inhibition, which has been interpreted from thermal and kinetic standpoints. In all the flames, the classic tulip shape was observed. With different inhibitor concentration, the flame demonstrated three types of deformation after the classic tulip inversion. A simple theoretical analysis has also been conducted to indicate that the pressure wave generated upon the first flame-wall contact can affect the flame deformation depending on its meeting moment with the flame front. Most importantly, the meeting moment is always behind the start of tulip inversion, which suggests the non-dominant role of pressure wave on this featured phenomenon. 相似文献
7.
《International Journal of Hydrogen Energy》2020,45(16):10164-10175
The lower flammability limits of H2/CO/air mixtures with N2 and CO2 dilution were systematic experimentally studied over a wide range of H2 blending ratios (0–100 vol%) with N2 (0–67 vol%) and CO2 (0–67 vol%) dilution in the fuels under various elevated initial temperatures (298 K–473 K) and atmospheric pressure. The experimentation was conducted via an 8 L stainless steel cylindrical explosion vessel and using the metal wire fusing as the ignition source. The corresponding cases were also calculated using Kondo's correlation proposed based on a limiting flame temperature concept. To gain an insightful understanding of the effect of chemical kinetics at different H2 fractions and CO2 dilution ratios, sensitivity analysis and H mole fractions were carried out using Chemkin-Pro. The experimental results showed that the lower flammability limits decreased with the increase of H2 fractions especially when the H2 content was low (xH2 ≤ 0.25). Attributable to the accelerated oxidation of CO by the greater generation of OH from H2/O2 reaction, Le Chatelier's Rule tended to relatively over-estimate the lower flammability limits of H2/CO mixtures with a small amount of H2. Because of the larger heat capacity, and the inhibition effect on the oxidation of CO and the generation of H radicals, CO2 presented a stronger dilution effect on lower flammability limit than N2. Moreover, the lower flammability limits for all measured syngas mixtures displayed great linear temperature dependence. A comparison between the experimental data and calculation results showed that, Kondo's correlation provided the satisfactorily accuracy predictions on the lower flammability limits of diluted syngas mixtures with lower H2 fractions (xH2 ≤ 0.5). However, when the H2 fractions were high and the mixture was highly CO2 diluted, Kondo's correlation over-estimated the lower flammability limits and the prediction error would reach to 30%. The considerably distinctions were not only attributed to the inadaptable assumption against to the growing and lower behaviour of H2 flame temperature at lower flammability limit, but also caused by the preferential diffusion of H2, as well as the variation of the chemical effects under high H2 content and high CO2 dilution conditions. 相似文献
8.
《International Journal of Hydrogen Energy》2022,47(9):6377-6387
This work is focused on the explosion characteristics of premixed gas containing different volume fractions of hydrogen in a narrow channel (1000 mm × 50 mm × 10 mm) under the circumstance of stoichiometric ratio. The ignition positions were set in the closed end and the middle of the pipeline respectively. The results showed that when the gas was ignited at the pipeline closed end, the propagating flame was tulip structure for different premixed gas. When the hydrogen volume fraction was less than 40%, the flame propagation speed increased significantly with the rise of hydrogen volume fraction, and the overpressure peak also appeared obviously in advance. However, when the volume fraction of hydrogen was more than 40%, the increase of flame propagation speed and the overpressure peak occurrence time varied slightly. Furthermore, when the ignition position was placed in the middle of the pipeline, the flame propagation speed propagating to the opening end was much faster than that propagating to the closing end, and there was no tulip shape when the flame propagates to the opening end. The flame propagating to the closed end appeared tulip shape under the influence of airflow, and high-frequency flame oscillation occurred during the propagation. This work shows that the hydrogen volume fraction and ignition position significantly affected the flame structure, flame front speed, and explosion overpressure. 相似文献
9.
《International Journal of Hydrogen Energy》2022,47(40):17808-17820
This article introduced the experimental study of the propagation of a syngas premixed flame in a narrow channel. The structural evolution, flame front position and velocity characteristics of lean and rich premixed flames were investigated at different hydrogen volume fractions as the flame was ignited at the open end of the pipe and propagated to the closed end. The comparative study of the syngas fuel characteristics, flame oscillation frequency and overpressure oscillation frequency prove that the syngas explosion flame oscillation in the narrow passage has a strong coupling relationship with overpressure and fuel heat release rate. The results was shown that the flame structure was strongly influenced by the hydrogen volume fraction of the syngas and the fuel concentration. The distorted tulip flame only appears in lean mixture. At 30% of hydrogen volume fraction, the flame exhibits intense and unstable propagation, manifested as the reciprocating and alternating movement of the flame front. As the volume fraction of hydrogen increased, the velocity of flame propagation and the frequency of oscillation increased. When the hydrogen volume fraction γ ≥ 0.4 at the equivalence ratio of Φ = 0.8, the pressure oscillation amplitude gradually increases and reaching the peak after 200–320 ms. Significantly, when γ = 0.3, the pressure peak increases abnormally. This work can provide support for the safe use of syngas in industry by experimental study of various explosion parameters in the narrow channel. 相似文献
10.
Meng Zhang Jinhua Wang Jin Wu Zhilong Wei Zuohua Huang Hideaki Kobayashi 《International Journal of Hydrogen Energy》2014
In order to investigate oxyfuel combustion characteristics of typical composition of coal gasification syngas connected to CCS systems. Instantaneous flame front structure of turbulent premixed flames of CO/H2/O2/CO2 mixtures which represent syngas oxyfuel combustion was quantitatively studied comparing with CH4/air and syngas/air flames by using a nozzle-type Bunsen burner. Hot-wire anemometer and OH-PLIF were used to measure the turbulent flow and detect the instantaneous flame front structure, respectively. Image processing and statistical analyzing were performed using the Matlab Software. Flame surface density, mean progress variable, local curvature radius, mean flame volume, and flame thickness, were obtained. Results show that turbulent premixed flames of syngas possess wrinkled flame front structure which is a general feature of turbulent premixed flames. Flame surface density for the CO/H2/O2/CO2 flame is much larger than that of CO/H2/O2/air and CH4/air flames. This is mainly caused by the smaller flame intrinsic instability scale, which would lead to smaller scales and less flame passivity response to turbulence presented by Markstain length, which reduce the local flame stretch against turbulence vortex. Peak value of Possibility Density Function (PDF) distribution of local curvature radius, R, for CO/H2/O2/CO2 flames is larger than those of CO/H2/O2/air and CH4/air flames at both positive and negative side and the corresponding R of absolute peak PDF is the smallest. This demonstrates that the most frequent scale is the smallest for CO/H2/O2/CO2 flames. Mean flame volume of CO/H2/O2/CO2 flame is smaller than that of CH4/air flame even smaller than that of CO/H2/O2/air flame. This would be due to the lower flame height and smaller flame wrinkles. 相似文献
11.
《International Journal of Hydrogen Energy》2022,47(81):34704-34714
The scaling-effect of mixture explosion is an unresolved issue in explosion science. In this work, we carry out experimental measurements of explosion characteristics using hydrogen/methane/air (H2/CH4/air) mixtures in two tubes with lengths of 1.5 m and 60 m. The explosion overpressure of the mixtures increases exponentially with hydrogen mole fractions in the small tube, as expected. In contrast, explosion overpressure increases rapidly, causing detonation when hydrogen is added to the mixtures. Comparing measurements in both tubes, the explosion overpressure exhibits a clear scaling-effect dependence on the tube size. The scaling-effect cannot be explained by the aspect ratio (AR) of the tube. The analysis of the hotspot size, which is correlated with the ignition delay time of mixtures, is the critical factor governing the scaling-effect of explosion seen in a large tube. 相似文献
12.
Nan DingRajat Arora Michael NorconkSeong-Young Lee 《International Journal of Hydrogen Energy》2011,36(4):3222-3231
In recent years, research efforts have been channeled to explore the use of environmentally-friendly clean fuel in lean-premixed combustion so that it is vital to understand fundamental knowledge of combustion and emissions characteristics for an advanced gas turbine combustor design. The current study investigates the extinction limits and emission formations of dry syngas (50% H2-50% CO), moist syngas (40% H2-40% CO-20% H2O), and impure syngas containing 5% CH4. A counterflow flame configuration was numerically investigated to understand extinction and emission characteristics at the lean-premixed combustion condition by varying dilution levels (N2, CO2 and H2O) at different pressures and syngas compositions. By increasing dilution and varying syngas composition and maintaining a constant strain rate in the flame, numerical simulation showed among diluents considered: CO2 diluted flame has the same extinction limit in moist syngas as in dry syngas but a higher extinction temperature; H2O presence in the fuel mixture decreases the extinction limit of N2 diluted flame but still increases the flame extinction temperature; impure syngas with CH4 extends the flame extinction limit but has no effect on flame temperature in CO2 diluted flame; for diluted moist syngas, extinction limit is increased at higher pressure with the larger extinction temperature; for different compositions of syngas, higher CO concentration leads to higher NO emission. This study enables to provide insight into reaction mechanisms involved in flame extinction and emission through the addition of diluents at ambient and high pressure. 相似文献
13.
Xuan Zhang Zuohua HuangZhiyuan Zhang Jianjun ZhengWu Yu Deming Jiang 《International Journal of Hydrogen Energy》2009
The laminar burning velocities and Markstein lengths for the dissociated methanol–air–diluent mixtures were measured at different equivalence ratios, initial temperatures and pressures, diluents (N2 and CO2) and dilution ratios by using the spherically outward expanding flame. The influences of these parameters on the laminar burning velocity and Markstein length were analyzed. The results show that the laminar burning velocity of dissociated methanol–air mixture increases with an increase in initial temperature and decreases with an increase in initial pressure. The peak laminar burning velocity occurs at equivalence ratio of 1.8. The Markstein length decreases with an increase in initial temperature and initial pressure. Cellular flame structures are presented at early flame propagation stage with the decrease of equivalence ratio or dilution ratio. The transition positions can be observed in the curve of flame propagation speed to stretch rate, indicating the occurrence of cellular structure at flame fronts. Mixture diluents (N2 and CO2) will decrease the laminar burning velocities of mixtures and increase the sensitivity of flame front to flame stretch rate. Markstein length increases with an increase in dilution ratio except for very lean mixture (equivalence ratio less than 0.8). CO2 dilution has a greater impact on laminar flame speed and flame front stability compared to N2. It is also demonstrated that the normalized unstretched laminar burning velocity is only related to dilution ratio and is not influenced by equivalence ratio. 相似文献
14.
This work experimentally investigates the effect of the presence of water vapor on the laminar flame speeds of moist syngas/air mixtures using the counterflow twin-flame configuration. The experimental results presented here are for fuel lean syngas mixtures with molar percentage of hydrogen in the hydrogen and carbon monoxide mixture varying from 5% to 100%, for an unburned mixture temperature of 323 K, and under atmospheric pressure. At a given equivalence ratio, the effect of varying amount of water vapor addition on the measured laminar flame speed is demonstrated. The experimental laminar flame speeds are also compared with computed values using chemical kinetic mechanisms reported in the literature. It is found that laminar flame speed varies non-monotonically with addition of water for the carbon monoxide rich mixtures. It first increases with increasing amount of water addition, reaches a maximum value, and then decreases. An integrated reaction path analysis is further conducted to understand the controlling mechanism responsible for the non-monotonic variation in laminar flame speed due to water addition. On the other hand, for higher values of H2/CO ratio the laminar flame speed monotonically decreases with increasing water addition. It is shown that the competition between the chemical and thermal effects of water addition leads to the observed response. Furthermore, reaction rate sensitivity analysis as well as binary diffusion coefficient sensitivity analysis are conducted to identify the possible sources of discrepancy between the experimental and predicted values. The sensitivity results indicate that the reaction rate constant of H2 + OH = H2O + H is worth revisiting and refinement of binary diffusion coefficient data of N2–H2O, N2–H2, and H2–H2O pairs can be considered. 相似文献
15.
Kai Zheng Minggao Yu Yunpei Liang Ligang Zheng Xiaoping Wen 《International Journal of Hydrogen Energy》2018,43(7):3871-3884
In this paper, large eddy simulation (LES) is performed to investigate the propagation characteristics of premixed hydrogen/methane/air flames in a closed duct. In LES, three stoichiometric hydrogen/methane/air mixtures with hydrogen fractions (volume fractions) of 0, 50% and 100% are used. The numerical results have been verified by comparison with experimental data. All stages of flame propagation that occurred in the experiment are reproduced qualitatively in LES. For fuel/air mixtures with hydrogen fractions of 0 and 50%, only four stages of “tulip” flame formation are observed, but when the hydrogen fraction is 100%, the distorted “tulip” flame appears after flame front inversion. In the acceleration stage, the LES and experimental flame speed and pressure dynamic coincide with each other, except for a hydrogen fraction of 0. After “tulip” flame formation, all LES and experimental flame propagation speeds and pressure dynamics exhibit the same trends for hydrogen fractions of 0 and 100%. However, when the hydrogen fraction is 50%, a slight periodic oscillation appears only in the experiment. In general, the different structures displayed in the flame front during flame propagation can be attributed to the interaction between the flame front, the vortex and the reverse flow formed in the unburned and burned zones. 相似文献
16.
《International Journal of Hydrogen Energy》2019,44(21):11185-11193
The CO/H2/CO2/O2, CO/H2/CO2/air turbulent premixed flames as the model of syngas oxyfuel and syngas/air combustion were studied experimentally and compared to that of CH4/air mixtures at high pressures up to 1.0 MPa. Hydrogen ratio in syngas was set to be 35%, 50% and 65% in volumetric fraction. Four perforated plates are used to generate wide range of turbulence intensity and scales. The instantaneous flame structure was measured with OH-PLIF technique and then statistic flame structure parameters and turbulent burning velocity were derived to interpret the multi scale turbulence-flame interaction. Results show that the flame structure of syngas is wrinkled and convex cusps to the unburned mixtures are sharper and deeper comparing to that of CH4 flames. Pressure has a dominating effect on flame wrinkling other than mixtures composition at high pressure of 1.0 MPa. The flame surface density, Σ of syngas is larger than that of CH4. The Σ of syngas flames is almost independent on pressure and hydrogen ratio especially when hydrogen ratio is over 50% which is a significant feature of syngas combustion. Larger flame surface density for syngas flames mainly comes from the finer structure with smaller wrinkles which is the result of more intensive flame intrinsic instability. The ST/SL of syngas is larger than CH4 and it slightly increases with the pressure rise. The ST/SL of syngas oxyfuel is similar to that of syngas/air flames in the present study. The ST/SL increases with the increase of hydrogen ratio and keeps almost constant when hydrogen ratio is over 50%. 相似文献
17.
Hong-Meng Li Guo-Xiu Li Yan-Huan Jiang 《International Journal of Hydrogen Energy》2018,43(33):16344-16354
An experimental study was conducted using outwardly propagating flame to evaluate the laminar burning velocity and flame intrinsic instability of diluted H2/CO/air mixtures. The laminar burning velocity of H2/CO/air mixtures diluted with CO2 and N2 was measured at lean equivalence ratios with different dilution fractions and hydrogen fractions at 0.1 MPa; two fitting formulas are proposed to express the laminar burning velocity in our experimental scope. The flame instability was evaluated for diluted H2/CO/air mixtures under different hydrogen fractions at 0.3 MPa and room temperature. As the H2 fraction in H2/CO mixtures was more than 50%, the flame became more unstable with the decrease in equivalence ratio; however, the flame became more stable with the decrease in equivalence ratio when the hydrogen fraction was low. The flame instability of 70%H2/30%CO premixed flames hardly changed with increasing dilution fraction. However, the flames became more stable with increasing dilution fraction for 30%H2/70%CO premixed flames. The variation in cellular instability was analyzed, and the effects of hydrogen fraction, equivalence ratio, and dilution fraction on diffusive-thermal and hydrodynamic instabilities were discussed. 相似文献
18.
《International Journal of Hydrogen Energy》2019,44(44):24321-24330
The self-acceleration characteristics of a syngas/air mixture turbulent premixed flame were experimentally evaluated using a 10% H2/90% CO/air mixture turbulent premixed flame by varying the turbulence intensity and equivalence ratio at atmospheric pressure and temperature. The propagation characteristics of the turbulent premixed flame including the variation in the flame propagation speed and turbulent burning velocity of the syngas/air mixture turbulent premixed flame were evaluated. In addition, the effect of the self-acceleration characteristics of the turbulent premixed flame was also evaluated. The results show that turbulence gradually changes the radius of the premixed flame from linear growth to nonlinear growth. With the increase of turbulence intensity, the formation of a cellular structure of the flame front accelerated, increasing the flame propagation speed and burning speed. In the transition stage, the acceleration exponent and fractal excess of the turbulent premixed flame decreased with increasing equivalence ratio and increased with increasing turbulence intensity at an equivalence ratio of 0.6. The acceleration exponent was always greater than 1.5. 相似文献
19.
Jianfei Xi Ye Yuan Weiben Yang Xianpeng Zhang Shengfu Wang 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2018,40(7):821-829
The effect of CO2/N2/CH4 dilution on NO formation in laminar coflow H2/CO syngas diffusion flames was experimentally and numerically investigated. The results reveal that the NO emission index increases with H2/CO mole ratio. In all cases, CO2/N2/CH4 dilution can reduce the peak temperature of syngas flame and have the ability to reduce peak flame temperature is decreased in the following order: CO2>N2>CH4. CO2/N2 dilution reduces the NO formation in syngas flame while CH4 dilution promotes the NO formation. Besides, the dilution of CO2/N2/CH4 can reduce the peak mole fraction of OH and its variations with H2/CO mole ratio and dilution ratio show the same trend as the peak flame temperature variations. The height of the flame with CO2 and N2 dilution increases with dilution ratio. The flame with CH4 dilution becomes higher and wider with the increase of dilution ratio. 相似文献
20.
《International Journal of Hydrogen Energy》2022,47(83):35171-35183
Syngas is a promising alternative energy carrier with low carbon and pollutants emissions, which has huge application potential in internal combustion engines and gas turbines. The combustion characteristics of stoichiometric syngas/air mixtures with varied initial pressure (0.5–2.5 atm) and hydrogen content (10%–90% v/v) were examined through experiments in a rectangular closed channel. The flame images and overpressure dynamics were captured by high-speed schlieren photography and pressure sensors. The flame instabilities and the flame-acoustic wave interaction were explored. The results showed that the flame morphology and dynamics were enhanced with increasing hydrogen content and initial pressure. The Darrius-Landau instability has an impact on flame deformation, which was strengthened with growing initial pressure, while the thermo-diffusive instability could be neglected during combustion. At later stages after tulip inversion, the flame-acoustic wave interaction was relatively outstanding inducing wrinkled flame front and cellular structures on the flame surface. 相似文献