Expt 7: Flame Spread over a Solid Fuel Surface

Effect of tilt on the flame spread rate

  • As the tilt angle is increased, initially a sharp decrease in the flame spread rate is observed (till ? = 30°).

  • Beyond ? = 30°, the change in the flame spread rate in marginal.

  • The higher flame spread rate at the tilt angle ? = 0°, is due to buoyancy.


Effect of soaking on the flame spread rate






  • Soaking of fuel with another fuel (Jet A1 or aviation turbine fuel) increases the flame spread rate.

  • However, soaking with a retardant will obviously reduce the flame spreading rate.


Effect of fuel thickness on the flame spread rate

  • As the fuel thickness increases, the flame spread rate decreases.

  • With increase in fuel thickness, the residence time of flame become more and resulting in a lower flame spread rate.

  • Hence the flame propagates at a faster rate for solid fuel with less thickness.