Pyrolysis behavior of hybrid rocket solid fuels under rapid heating conditions

Solid-Fuel Regression Rate Modeling for Hybrid Rockets

“…The value of E 1 (activation energy divided by the gas constant, here ≈ 1200 K) is set to a value lower than the one for the inert case (here E 2 ≈ 2500 K), because Pennsylvania State University's experiments [8] (from which the value of E 1 is taken) demonstrate that the presence of oxygen will enhance the pyrolysis (hence a lower activation energy, around a half of the inert one given by Chiaverini and coworkers in [13]). Hence it is, in a sense, like accounting for the oxygen increment twice: once through an increased pre-exponential constant (c + (ρ s Y os )) and once through a decreased value of E. Considering now a fixed value of T s ≥ 1000 K, the first exponential term (with E 1 ) is around three times bigger than the second term with E 2 .…”

“…First, the increase in the surface temperature, as explained before, will enhance the values of the exponential in the Arrhenius form of the pyrolysis law of Equation (35). Also, the value of the pre-exponential constant is different whether an inert local environment is considered or oxygen is present at the surface [8], [13]. The dependence of law (35) on the oxygen mass fraction at the surface gives a small increase of the regression-rate above the value with no oxygen at the solid surface.…”

Scale effect of fuel regression rate in hybrid rocket motor

“…Experimental data by Chiaverini et al [2] indicated that the composition of the fuel pyrolysis products is 1,3-butadiene. The combustion mechanism of 1,3-butadiene with hydrogen peroxide was approximated by a simplified two-step reaction model [21].…”

Experimental Investigation of Fuel Regression Rate in Hydroxyl-terminated-polybutadiene Gaseous-oxygen Hybrid Rocket Motors

“…Because of these safety and operational advantages, hybrid rocket motors could display lower manufacturing and launch costs than current propulsion systems. 4) Despite these benefits, hybrid rocket motors have not yet found widespread use for either military or commercial applications, possibly because they undergo slow solid fuel regression rates, low volumetric loading, and relatively poor combustion efficiency.…”

“…[4][5][6][7][8][9][10][11][12] Strand suggested the inclusion of particulate propellant ingredients in solid fuel as an approach to enhance solid fuel regression rate. 13) Korting et al conducted an experimental study with polymethyl-methacrylate (PMMA) and polyethylene as fuel, and oxygen and oxygen-nitrogen mixtures as oxidizers.…”