The time evolution of the surface tension of droplets of gasoline and alcohol blends was examined using the maximum bubble pressure method. Gasoline with an octane number of 95 was used as the basic fuel to be mixed in different proportions with ethanol or methanol. The burning process efficiency and exhaust gas composition in any combustion system was strongly influenced by the basic characteristics of the fuel spray. The characteristic time required to attain equilibrium surface tension is around 2 s. The droplets' size and size uniformity are two of the more important properties wherein smaller droplets will evaporate mix and burn faster than larger ones. At the time of the droplets' breaking up the surface tension may be 15%-25% higher than the equilibrium value and thus the mass of any individual droplet may exceed its predicted value when using the equilibrium value of the surface tension by 30%-70%.
- Dynamic surface tension
- Gasoline-ethanol and -methanol blends
- Maximum bubble pressure method (MBPM)