Experimental study on standing wave regimes of premixed H2–air combustion in planar micro-combustors partially filled with porous medium

Flame stabilization in a planar microcombustor partially filled with anisotropic porous medium

“…As such, only a few experimental studies on filtration combustion for millimeter‐scaled combustors could be found in the literature. To the authors' best knowledge, only silicon carbide foams, microfibrous ceramics, and stainless steel mesh have been applied in micro/mesocombustors, with the details given in Table . In our earlier studies, fine stainless steel mesh was used as the porous medium to fill into planar microcombustors with H = 1–2 mm .…”

“…To the authors' best knowledge, only silicon carbide foams, microfibrous ceramics, and stainless steel mesh have been applied in micro/mesocombustors, with the details given in Table . In our earlier studies, fine stainless steel mesh was used as the porous medium to fill into planar microcombustors with H = 1–2 mm . Critical conditions corresponding to the flame stability limits were experimentally identified for premixed H 2 /air combustion with different combustor sizes and filling conditions .…”

“…Critical conditions corresponding to the flame stability limits were experimentally identified for premixed H 2 /air combustion with different combustor sizes and filling conditions . Furthermore, a standing‐wave regime in which a stationary combustion could be achieved within the porous medium was observed and characterized with a systematic approach …”

“…In other words, the assumption of isotropic properties may not be valid as far as the present microcombustors are concerned, because porous structures exhibit homogeneity only when the sample size is beyond a certain level . For the three types of porous medium given in Table , it is believed that anisotropy would be inevitably introduced into the porous zone for the microfibrous ceramic due to its softness as well as the stainless steel mesh because of the folding and filling method employed, but their anisotropy could be neither characterized nor quantified, and therefore its effects on flame characteristics could not be understood even in a qualitative way. In view of that problem, this study is intended to answer the above question by “exaggerating” the anisotropy to investigate its effects on the flame stability limits in a planar microcombustor partially filled with porous medium, and the results obtained could potentially provide some guidance or clues to the design and operation of porous microcombustors.…”

Temperature and radiative characteristics of cylindrical porous Ni–Al burners

“…The flame is stabilized outside porous burner, when the burner power exceeds 1000 kW/m 2 [12]. The flame stabilization inside the porous burner carcass causes difficulties, especially for large scale porous burners [13,14], because of possibility of flashback, when the flame can penetrate into the mixing chamber of the burner and cause explosion of the gas mixture. In order to avoid the flashback, the dual layer porous burners made of dissimilar materials are used.…”