smaller and designed to test how the gauging technology will work with settled, non-sloshing liquids. Zero Gravity Corporation / Steve Boxall Rocket off course? It could be a slosh problem. Propellant slosh, to be exact. The motion of propellant inside a rocket-based launch vehicle or spacecraft tank is an ever-present, vexing problem for spaceflight. Not only can it make gauging the amount of available propellant difficult, but the volatile waves of liquid can literally throw a rocket off its trajectory. “To understand why it’s such a critical issue, it’s important to realize that for most launch vehicles, liquid propellant initially makes up nearly 90% of the vehicle mass,” explained Kevin Crosby of Carthage College in Kenosha, Wisconsin. Crosby is the principal investigator for a slosh control system supported by NASA’s Flight Opportunities program. The innovation will be tested on flights in Nov. 2020 from Zero Gravity Corporation on the company’s G-FORCE ONE modified parabolic airplane, which provides brief periods of microgravity. “As propellant is used over the course of a mission, room becomes available in the tank for it to slosh,” said Crosby. “And every time you fire an engine, it creates intense vibration and even more potential for the liquid to be disturbed.” Crosby explained that without any slosh mitigation, the risk of losing control of the launch vehicle can increase dramatically. While many slosh suppression methods already exist, Crosby noted that most can only be used in spherical tanks. Lower-mass and lower-cost options are needed for the cylindrical tanks often used in rocket-based launch vehicles. To address the challenge, Crosby – along with co-investigator Sathya Gangadharan of Embry-Riddle Aeronautical University (ERAU) in Daytona Beach, Florida, and students from both institutions – are testing a method that attempts to control slosh by using magnetic forces. Prior to the current parabolic flight campaign, Flight Opportunities funded tes

# What novel tank designs and ideas are out there to prevent fuel in a rocket tank from "sloshing around"? Tags: rockets, tanks, fuel-system, external-tank - Score: 5 - Views: 1558 - Answers: 2 - Answered: yes - Asked by: Dagelf (733 rep) - Asked: 2021-10-15 - Site: space ## Question After seeing all the Starship failures, having something with a membrane keep things in place seems like an obvious solution. Bladder tanks and "balloons" have been discussed here: Why is an inflatable balloon inside a fuel tank not used to prevent fuel from "sloshing around"? What other novel solutions, apart from pressurization with another gas, or a bladder tank, have been proposed and tried? For example, have rotating tanks, or other designs such as a tank with a compression arm and membrane, or a heavier liquid or something else like floating pebbles or pouches that can provide enough downward pressure, been tried? Or what about some novel tank design with an intricate coral-like structure inside? What are the advantages and disadvantages of some of these designs? ## Answers ### Answer by David Hammen (score: 9) Sloshing is not a problem in zero-g conditions. A key challenge with regard to

Fluid Sloshing Characteristics in Spacecraft Propellant Tanks with Diaphragms - NASA Technical Reports Server (NTRS) ## NTRS ## NTRS - NASA Technical Reports Server Search The auto‑search feature has been disabled based on user feedback. Enter a search term/phrase and click “Search” to begin. Back to Results Fluid Sloshing Characteristics in Spacecraft Propellant Tanks with DiaphragmsAll spacecraft are launched from the Earth as payloads on a launch vehicle. During portions of the launch profile, the spacecraft could be subjected to nearly purely translational oscillatory lateral motions as the launch vehicle control system guides the rocket along its flight path. All partially-filled liquids tanks, even those with diaphragms, exhibit sloshing behavior under these conditions and some tanks can place large loads on their support structures if the sloshing is in resonance with the control system oscillation frequency. The objectives of this project were to conduct experiments using a full-scale model of a flight tank to 1) determine whether launch vehicle vibrations can cause the diaphragm to achieve a repeatable configuration, regardless of initial condition, and 2) identify t