Session: 10-05-01: Multiphase Flows

Paper Number: 99385

99385 - Benchmarking a Multi-Phase Fluid Model of a Slosh Mitigation Device in Microgravity Utilizing Parabolic Flight Test Data 

The behavior of liquids in microgravity is highly chaotic and unpredictable, leading to performance instabilities in launch vehicles and spacecraft carrying liquid propellants. Sloshing is observed inside the propellant tanks of these vehicles in a microgravity environment. A slosh mitigation device, dubbed Magneto-Active Propellant Management device (MAPMD) has been developed at Embry-Riddle Aeronautical University (ERAU). The device utilizes a magneto-active floating membrane and magnets to effectively damp the liquid-free surface motion. The technical demonstration of the device was carried out onboard NASA’s Zero-G parabolic flight aircraft in collaboration with Carthage College. This research focuses on the CFD simulation of MAPMD subjected to the parabolic flight acceleration profiles. A Multi-phase CFD model of the slosh tank was analyzed using STAR_CCM+. The fluid properties of each phase: air and water were predicted using the Volume of Fluid (VOF) method. RANS model was used to solve the flow equations along with the k-omega turbulence model. An overset mesh was applied around the floating membrane to follow the motion of the object without mesh deformation, thereby reducing the associated computational expense. The dynamic Fluid Body Interaction (DFBI) model was utilized to predict the forces due to liquid pressure and shear, mechanical contact, and gravity on the solid membrane surfaces. Six different flight parabolas were simulated and the results were recorded.

The goal of this research was to benchmark a CFD methodology to simulate sloshing and MAPMD which will be flown on suborbital flights for long-duration microgravity testing. The parabolic flights provided short durations of microgravity which were not sufficient to fully characterize the flow development and membrane behavior. A subsequent flight test will be conducted onboard PLD Space's MIURA 1 rocket. This suborbital flight would provide 3-4 minutes of microgravity which is a sufficient period for bulk flow to reach equilibrium in microgravity. 

Contact modeling was performed to resolve structural interaction between the membrane and the tank walls. The solution time for this model was four times higher in magnitude compared to a simulation without a contact model. Therefore, contact in low impact directions was ignored and the motion of the membrane was restricted to 4 degrees of freedom. This underlying assumption impacted the membrane behavior in simulation when compared to video graphics data from parabolic flights. A Fluid structure-interaction model along with a 6-DOF full impact model is recommended for future study to fully resolve fluid and membrane behavior. These initial models developed using parabolic data will be used as a baseline for future full-scale simulations of the suborbital flight experiments. 

Presenting Author: Sathya Gangadharan Embry-Riddle Aeronautical University

Presenting Author Biography: Dr. Sathya Gangadharan is a Professor of Mechanical Engineering at Embry-Riddle Aeronautical University. Dr. Gangadharan has 32 years of academic research and teaching experience. His research interests include System Identification/Parameter Estimation, Modeling and Design Optimization, Fluid-Structure Interactions, and Manufacturing. He has over 60 technical research publications and worked as the principal investigator on research projects totaling over 2 million dollars. Dr. Gangadharan was awarded the prestigious NASA Summer Faculty Fellowship three times during 2003-2005. He also served as the advisor for 15 student microgravity projects as a part of the NASA Reduced Gravity Student Flight Program (RGSFP) in the past. In 2010 and 2011, Dr. Gangadharan participated in the FAST program where he successfully completed two flights with 40 parabolas of microgravity for each flight.

Authors:

Vijay Vishal Duraisamy Embry-Riddle Aeronautical University
Pedro Llanos Embry-Riddle Aeronautical University
Birce Dikici Embry-Riddle Aeronautical University
Sathya Gangadharan Embry-Riddle Aeronautical University