Here is a photo of one of my own woodgas stoves while it is burning gas at its secondary air jets ( a smokeless burn ):
Notice how the flames seems to come out of the sides where the Secondary Air Jets are. Where the air and the wood-gas mixes.
Photo of secondary air jets:
I usually load it with sticks like these ( about 2.5 cm in length and 8mm in diameter ):
I used these two coffee cans, one new and one from a dump, to build this stove:
The diameter of the outer can is 12.6 cm and the inner can is 10 cm. The advantage of using such a tall outer can is that the bottom will not get so hot that it starts to burn whatever it stands on. My smaller stove for backpacking has very little distance the outer can and the inner can at the bottom, it will actually burn green grass totally black and make it smoke where it stands. It could potentially start a fire if not put on a rock or something which will not burn.