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.
Decoupling and recoupling of detonation waves associated with sudden expansion
Detonation propagation behavior associated with sudden expansions has been investigated both experimentally and numerically. Different mechanisms, from sustained propagation to detonation failure and reinitiation including shock and flame front decoupling and recoupling have been observed with the schlieren technique. The shock-induced flame propagation has been modeled with two-step chemistry and structured two-dimensional CFD on arbitrary geometries. The results of the numerical simulations show good correspondence to the variety of phenomena observed in experiments. Thus the numerical simulation can be used to study detonation propagation in complex geometries. It provides a tool for the design of safety devices and aids experimental investigations.
Development of slit-type pressure differentiator using an isothermal chamber
Recently, measurement of the differentiated value of pressure has become necessary to realize precise control of pneumatic apparatuses. This paper proposes a pressure differentiator that contains a slit-type laminar flow element and an isothermal chamber. The underlying principle and the design method for the sensor are detailed. Then, simulations and experiments are conducted. The results verify the effectiveness of the proposed sensor and its potential in future applications.