Micro and Full-Scale Experiments on Hybrid Rocket Fuel and Prelude to Hybrid Rocket Combustor Simulations

Abstract

The high density polyethylene, as hybrid rocket fuel, has been chosen to be studied. Thermogravimetric analysis allowed to determine an Arrhenius type equation for its regression rate. A flash pyrolysis coupled to GC/MS/FID has been used to observe influence of oxidative environment on pyrolysis byproducts quantity. With a test bench, the regression rate of the solid fuel under various conditions (pressure, oxidizer mass flow rate, oxygen mass fraction) has been evaluated at an average value of 0.2 mm.s -1 . The Marxman law is completed with other studies conducted at higher oxidizer mass flow rates, between 0.6 and 20 g.s -1 .cm -2 . Finally, the first hybrid rocket combustor simulation is presented along its governing equations. Preliminary comparison gives a numerical regression rate 10% above the value found during experimental firing despite assumptions on the gas phase model. Nomenclature= nozzle throat area = pre-exponential factor = specific heat = energy of activation = soot particle diameter = form factor = soot volume fraction = body forces = oxidizer mass flow rate = enthalpy of reaction