AIAA Propulsion and Energy Forum is the only forum that covers both aeronautics and space propulsion and energy technologies in one place. The 2021 forum will explore how innovations in the propulsion and energy industries are enabling sustainability. Topics include electric propulsion, gas turbine engines, hybrid rockets, high-speed air-breathing propulsion, advanced energy technologies, and more. Discover how the aerospace community is fueling the future and expanding horizons.
Space Enabled will present the following papers:
Session: HR-03, Hybrid Fuel Manufacturing
Session day/time: August 9, 2021 from 2:30 PM to 3:45 PM Eastern Daylight Time
Technical Discipline: Hybrid Rockets: Descriptions of Current Programs – their Objectives and Progress to Date
Javier Stober, M. Regina Apodaca M., Alana Sanchez, Anika Kamath, Gabriel Owens-Flores, Dinuri Rupasinghe, Ana Emilia Hernandez Lara, Gladys Chepkirui Ngetich, Danielle Wood.
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.
Daniele Leuteri Costanzo, Javier Stober, Danielle Wood, Camilla Colombo. Completed in collaboration of COMPASS Group of Politecnico di Milano.
The purpose of this research is to explore the possibility of using paraffin wax as fuel to deorbit small satellites, potential mean to tackle space debris mitigation. Experiments conducted by the Space Enabled Research Group have been characterised by the use of paraffin as working fluid, with rotation rates ranging from 50-1500 rpm, and initial temperature of 75- 100 °C. The work conducted by the authors investigates the possibility of performing centrifugal casting of paraffin into annular shapes while the spacecraft is in orbit. The adopted strategy considers using the wax as thermal insulator and, at the end-of-life, recast it as fuel to allow a controlled reentry of the satellite. The workflow is conceived such that the wax will be melted and conveyed into the combustion chamber, which - spun by a DC motor - allows the wax to be shaped into a hollow cylinder. This paper describes the results obtained from a parametric system-level simulation tool, developed in a Matlab/Simulink environment, for the simulation of the thermal behavior of a spacecraft in Earth orbit, as well as performing mission analysis and thermal control design.
Gladys Chepkirui Ngetich, Javier Stober, Danielle Wood.
Paraffin wax as an alternative hybrid rocket propellant has received a lot of attention from researchers because of its attractive characteristics; high-performing, non-toxic, reusable, and easy to store. Paraffin wax fuel grains are normally manufactured through a centrifugal casting process. In the centrifugal casting process, fluid properties such as viscosity and casting tube geometrical parameters have a direct impact on the quality of the final cast product. In order to further understand and predict various heat and mass flow phenomena, and even optimise the centrifugal casting process, it is necessary to study fluid flow patterns in the centrifugal casting process. This research paper numerically investigates the influence of rotational speed and fluid viscosity in the centrifugal casting process of paraffin wax. Finite volume code in the Computational Fluid Dynamics (CFD) solver ANSYS Fluent was employed for the simulations. Liquid viscosity (water, SAE 5W-30 motor oil, and paraffin wax dotriacontane C32H66), and rotational speeds (1000 RPM, 2220 RPM, and 3000 RPM) were studied. From the transient twophase isothermal simulations, it was noted that viscosity played a major role in the centrifugal casting process; with high viscosity liquids like SAE 5W-30 motor oil forming a smooth, reliable annulus much faster, and even at relatively lower rotational speeds, unlike low viscosity liquids like water.