Jet velocity (v_x, v_y) at the flue exit. (a) The observation point C at the center of the flue exit and the sampling plane (the cross-section of the flue opening) over which v_x and v_y are integrated to obtain the averaged values ${\overline{v}}_x$ and ${\overline{v}}_y$, respectively. (b) Fluctuations of v_x at the point C for the three models. The inset shows the velocity distribution at t = 0.04 s in the operating portion for the Short model.