https://hdl.handle.net/1721.1/147049 2026-04-06T23:47:47Z https://hdl.handle.net/1721.1/146532 Optical and Thermochemical Analysis for Paraffin and Beeswax Centrifugal Casting Stober, Keith J; Sanchez, Alana; Apodaca M, M Regina; Ngetich, Gladys C; Wood, Danielle 2021-01-01T00:00:00Z https://hdl.handle.net/1721.1/146531 Modelling and simulation of in-orbit centrifugal casting of a paraffin wax grain inside a 3U CubeSat Leuteri Costanzo, Daniele; Stober, Keith Javier; Wood, Danielle; Colombo, Camilla 2021-01-01T00:00:00Z https://hdl.handle.net/1721.1/137063.2 Centrifugal Casting of Paraffin and Beeswax for Hybrid Rockets Stober, Keith J; Sanchez, Alana; Wanyiri, Juliet; Jiwani, Suzanna; Wood, Danielle Renee © 2020, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. A high-level research framework is presented which seeks to navigate the barriers associated with reusing wax phase change material onboard a satellite as a hybrid rocket fuel for de-orbit or other in-space propulsion needs, while also conducting fundamental studies of the fluid mechanics and heat transfer phenomena which drive the cooling and solidification of wax within a horizontal rotating cylinder in various gravitational and thermal environments. A detailed review of past work in the area of beeswax fuel for hybrid chemical propulsion is reported and served to motivate consideration of this fuel for centrifugal casting efforts, due to previously reported values of regression rate comparable to that of paraffin wax. The production process of beeswax fuel from beekeeping detritus was perfected and documented. Analysis of the shrinkage of beeswax and the neat Candlewic FR5560 paraffin wax used herein determined a volume shrinkage percentage during liquid to solid phase transition of 18.7 ± 0.62 and 13.3 ± 0.22%, respectively. An image analysis routine was developed in order to automate the process of determining the instantaneous solidification rate for each one-second timestep through the centrifugal casting process of paraffin and beeswax fuel grain sizes common for small-scale hybrid rockets. Beeswax completed solidification in 22% less time than paraffin under identical conditions but exhibited more coning of resulting solid wax. Calculated time-and space-averaged solidification rates for paraffin and beeswax were 0.017 and 0.028 mm/s, respectively, within a 50.8 mm inner diameter, 57.15 mm outer diameter, and 254 mm length polycarbonate tube. Careful analysis, however, shows that instantaneous solidification rate increases very slightly but steadily over time for both paraffin and beeswax, though the rate increase is greater for beeswax. The image analysis routine was most effective when applied to the beeswax solidification process as compared to that of paraffin, as the solid/liquid interface is considerably more salient in beeswax due to a distinct color change upon solidification. Dye will be used with paraffin casting in the future with the goal of improving solid/liquid phase contrast. 2020-08-01T00:00:00Z https://hdl.handle.net/1721.1/137063 Centrifugal Casting of Paraffin and Beeswax for Hybrid Rockets Stober, Keith J; Sanchez, Alana; Wanyiri, Juliet; Jiwani, Suzanna; Wood, Danielle © 2020, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. A high-level research framework is presented which seeks to navigate the barriers associated with reusing wax phase change material onboard a satellite as a hybrid rocket fuel for de-orbit or other in-space propulsion needs, while also conducting fundamental studies of the fluid mechanics and heat transfer phenomena which drive the cooling and solidification of wax within a horizontal rotating cylinder in various gravitational and thermal environments. A detailed review of past work in the area of beeswax fuel for hybrid chemical propulsion is reported and served to motivate consideration of this fuel for centrifugal casting efforts, due to previously reported values of regression rate comparable to that of paraffin wax. The production process of beeswax fuel from beekeeping detritus was perfected and documented. Analysis of the shrinkage of beeswax and the neat Candlewic FR5560 paraffin wax used herein determined a volume shrinkage percentage during liquid to solid phase transition of 18.7 ± 0.62 and 13.3 ± 0.22%, respectively. An image analysis routine was developed in order to automate the process of determining the instantaneous solidification rate for each one-second timestep through the centrifugal casting process of paraffin and beeswax fuel grain sizes common for small-scale hybrid rockets. Beeswax completed solidification in 22% less time than paraffin under identical conditions but exhibited more coning of resulting solid wax. Calculated time-and space-averaged solidification rates for paraffin and beeswax were 0.017 and 0.028 mm/s, respectively, within a 50.8 mm inner diameter, 57.15 mm outer diameter, and 254 mm length polycarbonate tube. Careful analysis, however, shows that instantaneous solidification rate increases very slightly but steadily over time for both paraffin and beeswax, though the rate increase is greater for beeswax. The image analysis routine was most effective when applied to the beeswax solidification process as compared to that of paraffin, as the solid/liquid interface is considerably more salient in beeswax due to a distinct color change upon solidification. Dye will be used with paraffin casting in the future with the goal of improving solid/liquid phase contrast. https://hdl.handle.net/1721.1/131214 Leveraging microgravity to investigate earth- And space-based centrifugal casting of wax Stober, Keith J; Sanchez, Alana; Apodaca Moreno, Maria Regina.; Ngetich, Gladys; Erkel, Daniel; Wanyiri, Juliet; Wood, Danielle A multi-year research effort aimed at increasing understanding of the centrifugal casting process of wax fuels for hybrid chemical propulsion in multiple thermal and gravitational environments is described. As both radiative and convective heat transfer drive the casting process, the suborbital and orbital microgravity environments are critical to disentangling these contributions to heat transfer away from the fuel. The experimental effort comprises testing on multiple platforms, including the ambient atmosphere of the laboratory, as well as various mobile microgravity platforms. Testing onboard reduced-gravity aircraft facilitates increased understanding of how these types of fluids perform in the microgravity environment, while a suborbital spaceflight and orbital platform under standard atmosphere allow for longer-term observation of natural convection sans buoyancy. An orbital platform subjected to the space environment facilitates understanding of the contribution of radiation to the heat transfer away from the liquid fuel. Each progressive testing environment requires updates to the experimental setup in order to accommodate respective physical and electrical constraints which are described in detail herein. An image analysis routine was developed in order to automate post-processing and determine the solidification front speed for each test. A rotation rate actuation routine is in development which aims to improve the accuracy of the centrifuge control system by leveraging electromagnetic sensing and feeding back rotation rate measurements to the motor driver. Preliminary modeling work was conducted which aims to elucidate the fundamental physics of the centrifugal casting problem; specifically, the impact of rotation rate, material properties, and environmental conditions on the heat transfer and fluid mechanics which constitute the larger casting problem. Both paraffin wax - a solid fuel with two decades of heritage - and the more novel beeswax are considered in this study. 2020-01-01T00:00:00Z