Ho, 21 April 2022, Science.The phenomenon of electrical oscillations in the case of a d-c discharge in hydrogen in tho region of the positive v-i characteristic has been investigated for the pressure range 40 to 200 microns, discharge voltages 0.6 to 11.2 kv, and discharge currents 0.1 to 2.5 ma.
Coherent oscillations were observed in the frequency range 40 to 100 kc/sec which were accompanied by three or four frequency groups in the range 170 to 2,300 kc/sec. The existence of a common cut-off current for all these frequencies has been shown which is found to depend on the pressure in such a manner that it has a maximum value for p = 60 to 90 microns. The frequencies of the oscillations show a significant dependence on i and p and are independent of the circuit parameters. The frequencies have a minimum value for p = 60 to 90 microns. The lower frequencies show only an insignificant variation with i whereas in the highest frequency group there is a very rapid rise of frequency with current. The model reproduced the range and change tendency of the experimentally measured oscillation frequency.The amplitude of the oscillations is determined by i and p and shows a maximum for some value of i and p = 60 to 90 microns. The resonant frequencies under both the 100% natural gas and hydrogen–natural gas conditions were successfully calculated. A whole piping model was then developed by adding a casing and an air supply pipe to the combustor. However, the model could not reproduce the experimental value under the hydrogen–natural gas condition. A swirler-combustor model was then constructed to get closer to the actual configuration and shape of the experimental setup. Conversely, the experimentally observed frequencies under the hydrogen–natural gas condition were not accurately predicted. The experimental frequencies of the 100% natural gas condition were successfully predicted. To analyze the resonant frequency, two- and four-region models considering unburned and burned regions of the combustor were developed. Journal of Verification, Validation and Uncertainty QuantificationĪ combustion oscillation experiment showed combustion oscillation frequencies of around 350 Hz when only natural gas was used as fuel and approximately 200 and 400 Hz when a hydrogen–natural gas mixture was used.Journal of Thermal Science and Engineering Applications.Journal of Offshore Mechanics and Arctic Engineering.Journal of Nuclear Engineering and Radiation Science.Journal of Nondestructive Evaluation, Diagnostics and Prognostics of Engineering Systems.
Journal of Computational and Nonlinear Dynamics.Journal of Autonomous Vehicles and Systems.ASME Letters in Dynamic Systems and Control.ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems, Part B: Mechanical Engineering.Mechanical Engineering Magazine Select Articles.
0 kommentar(er)
