Investigating Fluidized Granular Flow Behavior in Extraterrestrial Environments for a Pneumatic Regolith Acquisition System

Keeping in mind the enormous scientific benefits of bringing extraterrestrial samples back to Earth, efforts are undertaken to improve the performance of Honeybee Robotics’ Pneumatic Regolith Acquisition System: PLANETVAC. Positive pressure pneumatic conveying systems rely on complex layouts for particle transport and require efficient designs. For it to function with redundancy and without human interaction in extraterrestrial environments, it becomes imminent to model gas-solid flow behavior and put forth critical findings. There has yet to be a comprehensive study of fluidized granular flow in reduced (or zero) gravity environments to better assist design of EVA/ ISRU equipment for future missions. These findings shall induce design adjustments that will improve gasregolith mixing for efficient transport of the samples under Martian conditions. A critical area to model the flow is the “pneumatic injectionMartian Surface regolith zone”. Effects of pneumatic injection velocity vectors upon regolith volume fraction distribution and subsequent transport within the system is studied within a cylindrical pipe with inlets for gas injection onto the exposed regolith surface area. Key gas nozzle design variations are modeled and tested for appreciation of captured regolith mass. Swirl motion of gases have shown to impart higher momenta per square millimeter as compared to direct downward injection of gas. An increasing trend of injection angle shows a wider and uniform distribution of sand volume fraction, signifying a higher lift of sand particles.