The cavity may include a plurality of {TAIL ~ pedestals} and protrusions configured to create one or more spirals flow paths of a gas traveling through {HEAD ~ the cavity} 
The cavity may include a plurality of { TAIL ~ pedestals } and protrusions configured to create one or more spirals flow paths of a gas traveling through { HEAD ~ the cavity }
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD