**2.1 Wick combustion burner**

A wick flame was formed with a wick combustion burner, as shown in Fig. 1. The burner was equipped with a pool filled with fuel, and a wick was put in the pool. Fuel was supplied from a tank to the pool through a float chamber under the fuel tank. To form a steady flame, the fuel level within the pool was kept constant by the float. The fuel flow rate was derived from the weight loss of the burner, measured by an electronic balance. The pool was made of aluminium. The pool had an outer diameter of 20 mm, an inner diameter of 16 mm, and a depth of 6 mm. The wick, made of sintered bronze metal (39 % porosity), was placed in the centre of the pool. The wick was cylindrical (8 mm diameter, 18 mm length, 6 mm wall thickness) with a flat bottom (8 mm diameter, 2 mm thickness). The wick was put in the pool so that the bottom protruded 7 mm from the pool rim. The distance from the fuel surface to top of the wick was 10 mm.

Fig. 1. Schematic of wick combustion burner
