I think the wood burner below has potential, it had the best burn that I have seen with small wood and straw, but I am new to (wood gas?) burners so maybe not.
The improved center frame was simple and fast too build, it uses a spiral wire that is formed around a tube.
A funnel cut from the bottom of a pail (8" dia flat lay out) replaces the grate and focuses the combustion air and heated secondary combustion air up the center frame.
Small wood splinters and straw are used for fuel.
I light it from the bottom, Top lighting may be better.
It produced nice flames with no visible smoke.
Then the char burned and most of the ashes fell through the cone.
The next set up will control the combustion air to see if the burner can turn down without smoking.