Burning rate studies of fuel air mixtures at high pressures

High pressure burning studies of fuel air mixtures (mainly JP4 and air) were investigated in a closed chamber to determine what parameters control the maximum combustion rate and maximum pressure. The fuel was injected through shower-type nozzles into air at initial pressures ranging 2000-4000 psi. Densities of loading ranged 0.18-0.36 gm/cm³, and the equivalence ratio ranged 0.6-2.7 fuel to air. A method for evaluating the burning velocity is presented. It was found that a wide variation in the burning velocity could be obtained with maximum burning velocities occurring at minimum fucl air mixing times. The pressure-time history during the closed vessel explosion agrees remarkably well with a time cubed dependence. Such pressure-time data is used to interpret the pressure rise predicted by a simple isothermal model. It is shown that at these high pressures the initial mass burning rate is approximately proportional to a reduced pressure raised to the 2/3 power.