Stober, K.J., Apodaca M., M.R., Sánchez, A., Kamath, A., Owens-Flores, G., Rupasinghe, D., Hernández L., A.E., Ngetich, G.C., and Wood, D., "Optical and Thermochemical Analysis for Paraffin and Beeswax Centrifugal Casting," AIAA Propulsion and Energy Forum, August 2021

Abstract

Progress on the wax-based centrifugal casting project is presented. A chemical equilibrium solver was used to predict nearly identical but slightly superior performance of beeswax compared to paraffin under identical conditions and in the case where (1) gaseous oxygen and (2) nitrous oxide are employed as oxidizers. An experiment was conducted in the laboratory and onboard a microgravity aircraft flight which leveraged water, 5W-30 motor oil, liquefied paraffin wax at 100 ℃, and beeswax at 100 ℃ as working fluids in geometries on par with small-scale tabletop hybrid rocket fuel grains – 2 in. internal diameter and 10 in. internal length. Sixteen total microgravity parabolas were flown with rotation rates varying from 0 to 800 RPM. Annulus formation was dependent upon viscosity. Oil and paraffin produced annuli in microgravity at 150 RPM and most rotation rates above. Water twice produced annuli in microgravity at 550 and 800 RPM. Beeswax was not rotated in microgravity such that the static geometry of liquefied wax could be studied. Identical tests were conducted for oil and paraffin in the laboratory. Paraffin never achieved annulus when tested up to 800 RPM in the laboratory. Oil achieved annulus at 650 RPM and above.