检索结果-南通市图书馆

Defence Technology（防务技术） 2021年第5期17卷 1617-1624页

作者： Wan-li Wei Yu-wen Wu chun-sheng weng Quan Zheng National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyNanjing210094China

Due to the pressure gain combustion characteristics,the rotating detonation combustor(RDC)can enhance thermodynamic cycle ***,the performance of gas-turbine engine can be further improved with this combustion *** the present study,the RDC operation performance with a turbine guide vane(TGV)is experimentally *** and air are used as propellants while hydrogen and air mass flow rate are about 16.1 g/s and 500 g/s and the equivalence ratio is about 1.0.A pre-detonator is used to ignite the ***-frequency dynamic pressure transducers and silicon pressure sensors are employed to measure pressure oscillations and static pressure in the combustion *** experimental results show that the steady propagation of rotating detonation wave(RDW)is observed in the combustion chamber and the mean propagation velocity is above 1650 m/s,reaching over 84%of theoretical Chapman-Jouguet detonation *** and counterclockwise propagation directions of RDW are *** clockwise propagation direction,the static pressure is about 15%higher in the combustor compared with counterclockwise propagation direction,but the RDW dominant frequency is *** the oblique shock wave propagates across the TGV,the pressure oscillations reduces *** addition,as the detonation products flow through the TGV,the static pressure drops up to 32%and 43%for clockwise and counterclockwise propagation process respectively.

关键词： Rotating detonation combustor Propagation direction Turbine guide vane Operation performance

Experimental study of the influence of annular nozzle on acoustic characteristics of detonation sound wave generated by pulse detonation engine

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2022年第10期31卷 436-443页

作者： Yang Kang Ning Li Xiao-Long Huang chun-sheng weng National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyNanjing 210094China

Acoustic characteristics of the detonation sound wave generated by a pulse detonation engine with an annular nozzle,including peak sound pressure, directivity, and A duration, are experimentally investigated while utilizing gasoline as fuel and oxygen-enriched air as oxidizer. Three annular nozzle geometries are evaluated by varying the ratio of inner cone diameter to detonation tube exit diameter from 0.36 to 0.68. The experimental results show that the annular nozzles have a significant effect on the acoustic characteristics of the detonation sound wave. The annular nozzles can amplify the peak sound pressure of the detonation sound wave at 90° while reducing it at 0° and 30°. The directivity angle of the detonation sound wave is changed by annular nozzles from 30° to 90°. The A duration of the detonation sound wave at 90° is also increased by the annular nozzles. These changes indicate that the annular nozzles have an important influence on the acoustic energy distribution of the detonation sound wave, which amplify the acoustic energy in a direction perpendicular to the tube axis and weaken it along the direction of the tube axis.

关键词： pulse detonation engine annular nozzle detonation sound wave acoustic characteristics

In situ measurement on nonuniform velocity distributionin external detonation exhaust flow by analysis ofspectrum features using TDLAS

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2022年第1期31卷 417-427页

作者： Xiao-Long Huang Ning Li chun-sheng weng Yang Kang National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyNanjing 210094China

Instantaneous and precise velocity sensing is a critical part of research on detonation mechanism and flow *** paper presents a novel multi-projection tunable diode laser absorption spectroscopy solution,to provide a real-time and reliable measurement of velocity distribution in detonation exhaust flow with obvious *** are established between overlapped spectrums along probing beams and Gauss velocity distribution phantom according to the frequency shifts and tiny variations in components of light-of-sight absorbance profiles at low frequencies analyzed by the fast Fourier *** simulated optical measurement using H2O feature at 7185.6 cm-1 carried out on a phantom generated using a simulation of two-phase detonation by a two-fluid model,this method demonstrates a satisfying performance on recovery of velocity distribution profiles in supersonic flow even with a noise equivalent absorbance up to 2×10^(-3).This method is applied to the analysis of rapidly decreasing velocity during a complete working cycle in the external flow field of an air-gasoline detonation tube operating at 25 Hz,and results show the velocity in the core flow field would be much larger than the arithmetic average from traditional tunable diode laser doppler *** proposed velocity distribution sensor would reconstruct nonuniform velocity distribution of high-speed flow in low cost and simple operations,which broadens the possibility for applications in research on the formation and propagation of external flow filed of detonation tube.

关键词： velocity distribution tunable diode laser absorption spectroscopy nonuniform flow Doppler effect

Acoustic characteristics of pulse detonation engine sound propagating in enclosed space

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第1期29卷 378-386页

作者： Yang Kang Ning Li chun-sheng weng Xiao-Long Huang National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyNanjing 210094China

Acoustic characteristics of pulse detonation engine(PDE)sound propagating in enclosed space are numerically and experimentally *** finite element software LS-DYNA is utilized to numerically simulate the PDE sound propagating in enclosed *** measurement systems are established for testing the PDE sound in enclosed space,and the time-frequency characteristics of PDE sound in enclosed space are reported in *** experimental results show that the sound waveform of PDE sound in enclosed space are quite different from those in open space,and the reflection and superposition of PDE sound on the walls of enclosed space results in the sound pressure oscillating *** is found that the peak sound pressure level(PSPL)and overall sound pressure level(OASPL)of PDE sound in enclosed space are higher than those in open space and their difference increases with the rise of propagation *** results of the duration of PDE sound indicate that the A duration of PDE sound in enclosed space is higher than that in open space except at measuring points located at 2-m and 5-m while the B duration is higher at each of all measuring *** show that the enclosed space has a great influence on the acoustic characteristic of PDE *** research is helpful in performing PDE experiments in enclosed laboratories to prevent the PDE sound from affecting the safety of laboratory environment,equipment,and staffs.

关键词： pulse detonation engine acoustics characteristics enclosed space

Acoustic characteristics of pulse detonation engine with ellipsoidal reflector

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第10期27卷 413-423页

作者： Yang Kang Ning Li chun-sheng weng Chuan-Wei Wang National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyNanjing 210094China

Acoustic characteristics of a pulse detonation engine（PDE） with and without an ellipsoidal reflector are numerically and experimentally investigated. A two-dimensional（2 D） non-splitting unstructured triangular mesh Euler solver based on the space-time conservation element and solution element（CE/SE） method is employed to simulate the flow field of a *** numerical results clearly demonstrate the external flow field of the PDE. The effect of an ellipsoidal reflector on the flow field characteristic near the PDE exit is investigated. The formation process of reflected shock wave and reflected jet shock are reported in detail. An acoustic measurement system is established for the PDE acoustic testing. The experimental results show that the ellipsoidal reflector changes the sound waveform and directivity of PDE sound. The reflected shock wave and reflected jet shock result in two more positive pressure peaks in the sound waveform. The ellipsoidal reflector changes the directivity of PDE sound from 20 to 0. It is found that the peak sound pressure level（PSPL） and overall sound pressure level（OASPL） each obtain an increment when the PDE is installed with a reflector. The maximum relative increase ratio of PSPL and OASPL are obtained at the focus point F2, whose values are 6.1% and 6.84% respectively. The results of the duration of the PDE sound indicate that the reflecting and focusing wave generated by the reflector result in the increment of A duration and B duration before and near focus point F2. Results show that the ellipsoidal reflector has a great influence on the acoustic characteristic of PDE sound. The research is helpful for understanding the influence of an ellipsoidal reflector on the formation and propagation process of PDE sound.

关键词： pulse detonation engine ellipsoidal reflector acoustic characteristics experiments and simulations

Experimental study on propagation characteristics of rotating detonation wave with kerosene fuel-rich gas

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2022年第8期18卷 1498-1512页

作者： Jia-xiang Han Qiao-dong Bai Shi-jian Zhang Fang Wang chun-sheng weng National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyNanjing210094China

In this study, kerosene fuel-rich gas produced by the combustion in the gas generator was used as the fuel and oxygen-rich air was used as the oxidant to investigate the propagation characteristics of the rotating detonation wave (RDW). The initiation of the kerosene fuel-rich gas and propagation process of the RDW were analyzed. The influences of the oxygen content in the oxidizer, kerosene mass flow rate of the gas generator, and temperature of the kerosene fuel-rich gas on the propagation process of the RDW were studied. The experimental results revealed that the propagation velocity of the RDW could be improved by increasing the three parameters mentioned above with the kerosene mass flow rate as the strongest factor. The minimum oxygen content that could successfully initiate and maintain the stable propagation of the RDW was 32%, achieving the RDW velocity of 1141.9 m/s. The RDW mainly propagated as two-counter rotating waves and a single wave when the equivalent ratios were 0.62–0.79 and 0.85–0.87, respectively. The highest RDW velocity of 1637.2 m/s was obtained when the kerosene mass flow rate, oxygen content, and equivalent ratio were 74.6 g/s, 44%, and 0.87, respectively.

关键词： Rotating detonation wave Kerosene fuel-rich gas Initiation process Propagation mode

Effects of total pressures and equivalence ratios on kerosene/air rotating detonation engines using a paralleling CE/SE method

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2021年第6期17卷 1805-1816页

作者： Fang Wang chun-sheng weng Yu-wen Wu Qiao-dong Bai Quan Zheng Han Xu National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyNanjing210094China

In this paper,the kerosene/air rotating detonation engines(RDE)are numerically investigated,and the emphasis is laid on the effects of total pressures and equivalence ratios on the operation characteristics of RDE including the initiation,instabilities,and propulsive performance.A hybrid MPI t OpenMP parallel computing model is applied and it is proved to be able to obtain a more effective parallel performance on high performance computing(HPC)systems.A series of cases with the total pressure of 1 MPa,1.5 MPa,2 MPa,and the equivalence ratio of 0.9,1,1.4 are *** one hand,the total pressure shows a significant impact on the instabilities of rotating detonation *** instability phenomenon is observed in cases with low total pressure(1 MPa)and weakened with the increase of the total *** total pressure has a small impact on the detonation wave velocity and the specific *** the other hand,the equivalence ratio shows a negligible influence on the instabilities,while it affects the ignition process and accounts for the detonation velocity *** is more difficult to initiate rotating detonation waves directly in the lean fuel operation *** difference was observed in the thrust with different equivalence ratios of 0.9,1,and *** highest specific impulse was obtained in the lean fuel cases,which is around 2700 *** findings could provide insights into the understanding of the operation characteristics of kerosene/air RDE.

关键词： Kerosene/air rotating detonation waves Total pressure Equivalence ratio Instabilities MPItOpenMP

Experimental study on the detonation process of a pulse detonation engine with ionized seeds

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2020年第1期16卷 178-187页

作者： Ling Lin Shun-an Hu Yan-bin Hu Guang-ju Xu Hong-yu Jiao chun-sheng weng School of Automotive Engineering Changshu Institute of TechnologySuzhou215500China National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyNanjing210094China

An experimental platform of a pulse detonation engine(PDE) was established to study the effect of different K_2 CO_3 ionized seed mass contents on the detonation *** pressure and ion concentration were detected in the detonation process of the PDE with different contents of ionized *** initiation process of the PDE at different ignition frequencies was *** results show that the gas conductivity in the detonation process increased by adding ionized seeds to the PDE tube,and the conductivity increased with the increase in ionized seed mass *** the increase in ionized seed mass content,the range of the conductivity *** PDE was successfully ignited and formed a stable detonation wave at ignition frequencies of 5 Hz and 10 Hz,and the peak pressure of the stable detonation with the ignition frequency of 5 Hz was 17% higher than that with an ignition frequency of 10 *** detonation wave intensity was weake ned and dege nerated to a shock wave that propagated in the tube without the fuel filled at the ignition frequency of 20 Hz.

关键词： Pulse detonation engine Ionized seeds Detonation process Ignition frequency

Experimental research on the instability propagation characteristics of liquid kerosene rotating detonation wave

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2020年第6期16卷 1106-1115页

作者： Quan Zheng Hao-long Meng chun-sheng weng Yu-wen Wu Wen-kang Feng Ming-liang Wu National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyNanjing210094China

In order to study the instability propagation characteristics of the liquid kerosene rotating detonation wave(RDW),a series of experimental tests were carried out on the rotating detonation combustor(RDC)with *** fuel and oxidizer are room-temperature liquid kerosene and preheated oxygenenriched air,*** experimental tests keep the equivalence ratio of 0.81 and the oxygen mass fraction of 35%unchanged,and the total mass flow rate is maintained at about 1000 g/s,changing the total temperature of the oxygen-enriched air from 620 K to 860 *** different types of instability were observed in the experiments:temporal and spatial instability,mode transition and *** interaction between RDW and supply plenum may be the main reason for the fluctuations of detonation wave velocity and pressure peaks with ***,the inconsistent mixing of fuel and oxidizer at different circumferential positions is related to RDW oscillate *** phenomenon of single-double-single wave transition is *** the transition,the initial RDW weakens until disappears,and the compression wave strengthens until it becomes a new RDWand propagates *** increased deflagration between the detonation products and the fresh gas layer caused by excessively high temperature is one of the reasons for the RDC quenching and re-initiation.

关键词： Rotating detonation wave Liquid kerosene Oxygen-enriched air Instability propagation characteristics Compression wave

Experimental Research on the Propagation Process of Continuous Rotating Detonation Wave

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2013年第4期9卷 201-207页

作者： Quan ZHENG chun-sheng weng Qiao-dong BAI National Key Laboratory of Transient Physics Nanjing University of Science and Technology

In order to study the propagation mechanism of continuous rotating detonation wave,the H2/air continuous rotating detonation engine ignited by tangentially installed H2/O2pre-detonation tube is studied experimentally using a tilt slot injector *** experimental results show that the stable rotating detonation wave can be gained successfully with the equivalent ratio of *** propagation frequency and velocity of rotating detonation wave range from 5200 to 5500 Hz and from 1518.5 to 1606.1 m/s,*** propagation modes,such as rotation,reversal and bifurcation,of detonation wave are verified through the analysis of propagation mechanism of rotating detonation wave.

关键词：连续旋转传播过程爆轰波实验传播机制传播模式传播机理喷射器