Experimental research on a newly developed detonation flame arrester
In this research, a flame arrester consists of radial slit structure is developed. In order to determine the characteristic of the newly developed flame arrester, pressure response and detonation wave velocity are measured using two radial slit structures with different inside diameter. At first, the flow characteristics for the slit structures are investigated theoretically and experimentally. Then, the slit structures are applied to the flame arrester. Detonation experiments are performed for mixture gas of air and hydrogen. It reveals that the radial slit structure with the suitable inside diameter is effective for the flame arrester.
A Study on Behavior of Detonation Wave Passing through Narrow Grooves
A detonation wave produced in a combustible gaseous mixture might cause serious damages by interacting with an artificial structure or human bodies because of an extremely high-pressure and high-temperature behind this wave. Therefore, the detonation wave produced in the gaseous mixture and propagated into a circumstance by accident should be attenuated or quenched within a short distance from its origin. Experiments were conducted in order to investigate behaviors of the detonation wave passing through narrow grooves, since the detonation wave was accompained with a cellular structure and no detonation wave could be propagated. In this study, the detonation wave produced in a gaseous mixture of hydrogen and oxygen was propagated through a grooved block and behaviors of the detonation wave were experimentally investigated by using techniques of pressure measurement and soot track record. As a result, the behavior of detonation wave propagating through the grooved block was classified into two categories, i. e. (i) the detonation wave was quenched, (ii) the detonation wave was once quenched behind the block but re-initiated again by focusing mechanisms of a reflected shock wave on a central axis.
A Practical Solution to the Problem of Noise and Vibration in a Pressure Reducing Valve
Abstract The mechanical vibration that is occasionally found in gas pressure reducing valves can be eliminated by careful design of the valve plug and seat. A pressure-reducing valve was found to be excessively noisy, producing a sound pressure level of 117 dB when throttling air at an inlet-to-outlet pressure ratio of 15; as a result the valve suffered wear and vibration damage. By changing the design of the original flat plug and seat, the problem was significantly reduced. A 60° conical plug and seat produced a noise reduction of 12 dB (a factor of 4 in actual sound pressure level), the mechanical vibration was eliminated, and the flow capacity was increased by about 25%.