• fuel penetration rate;
  • liquid fuel;
  • porous bed;
  • Kozeny–Carman equation;
  • porosity;
  • permeability


Flame spread over porous media due to accidental fuel spillage is a major fire safety concern. The behaviour of flame under such conditions greatly depends on the availability of fuel at combustion zone. A combined experimental and mathematical study was carried out to investigate the rate of fuel penetration through porous beds at different fuel ratios. Propanol at three different fuel ratios of 0.1, 0.125 and 0.15 and sand particles ranging in diameters from 0.5 to 5 mm were employed as liquid fuel and porous bed, respectively.

Results showed that fuel penetration rate was a function of permeability of porous bed and mass of the liquid fuel. The permeability of porous bed and consequently the rate of fuel penetration decreased as either the tortuosity or the specific surface area was increased.

Fuel penetration measurement and mathematical results indicated that the rate of fuel penetration is directly proportional to the fuel ratio. The fuel penetration rate was found to be higher for larger fuel ratios compared with that for small ratios. The difference between the fuel penetration rate for two consecutive fuel ratios for a given particle size was 25%. The predicted results were in good agreement with those acquired experimentally. Copyright © 2012 John Wiley & Sons, Ltd.