Measurement of the burning velocity of propane-air mixtures using soap bubbles

Experiments have been performed to determine the burning velocity of propane-air mixtures over a wide range of equivalence ratios using soap bubbles and a hot-wire anemometer. This method gives a maximum burning velocity of 50 cm/s at an equivalence ratio of 1.1. The present maximum burning velocity agrees well with the theoretical result predicted by Warnatz. The values of the burning velocity determined in these experiments are also in relatively good agreement with those of other accurate methods using a burner. The flame-front instabilities of a hydrodynamic or diffusional-thermal origin are also discussed.