[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-183045-105":59,"doc-detail-183045-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","high-accuracy-liquid-propellant-slosh-predictions-using-an-integrated-cfd-and-controls-analysis-interface-research","High Accuracy Liquid Propellant Slosh Predictions Using an Integrated CFD and Controls Analysis Interface - Research","","High-fidelity predictions of sloshing liquid propellants and their interaction with launch vehicle control systems are achieved through a coupled interface linking a computational fluid dynamics solver with a controls analysis tool. By replacing indirect mechanical analogs that fail across flight stages, the method directly connects vehicle dynamic environments to the fluid flow equations, enabling mutual influence between fluid forces and control response. Results from multiple test cases are compared with established validated tools, demonstrating high accuracy.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":40,"@type":76,"position":81},"https://docshare.wps.com/document/research-report/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/high-accuracy-liquid-propellant-slosh-predictions-using-an-integrated-cfd-and-controls-analysis-interface-research/183045/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/high-accuracy-liquid-propellant-slosh-predictions-using-an-integrated-cfd-and-controls-analysis-interface-research/183045.png","ImageObject",300,407,{"name":92,"@type":93},"\tJames","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-09-18","2026-09-02",true,{"@type":102,"interactionType":103,"userInteractionCount":19},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"Why is propellant slosh coupling important for launch vehicle control predictions?","Question",{"text":112,"@type":113},"Sloshing propellant significantly affects the launch vehicle control system, so ignoring the interaction leads to inaccurate estimates of control response and propellant-related behavior.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"How does the proposed CFD-and-controls coupled method improve accuracy over mechanical analogs?",{"text":117,"@type":113},"Instead of relying on mechanical analogs valid only in limited conditions, the coupling runs both solvers simultaneously so fluid forces influence the control system and the control environment feeds back into the CFD solution.",{"name":119,"@type":110,"acceptedAnswer":120},"What limitations are associated with the pendulum analog approach?",{"text":121,"@type":113},"The pendulum analog is valid mainly for low-amplitude slosh and can break down when slosh waves become violent. It also cannot directly provide propellant location within the tank.","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},183045,1788351041,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":39,"category_name":40,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":19,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":52,"language":139,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":67,"update_tm":129,"read_time":143},2336474466412,"https://ap-avatar.wpscdn.com/davatar_155a257f0dc6eb9ab79c44ca47cae57d","# High Accuracy Liquid Propellant Slosh Predictions Using anIntegrated CFD and Controls Analysis Interface\n\nBrandon Marsell  \na.i.solutions,Launch Services Program,Kennedy Space Center,FL 32899  \nDavid Griffin  \na.i.solutions,Launch Services Program,Kennedy Space Center,FL32899  \nDr.Paul Schallhorn,Jacob Roth⁸NASA,Launch Services Program,Kennedy Space Center,FL32899  \nCoupling computational fluid dynamics(CFD)with a controls analysis toolelegantly allows for high accuracy predictions of the interaction between sloshing liquidpropellants and the control system of a launch vehicle.Instead of relying on mechanicalanalogs which are not valid during all stages of flight,this method allows for a direct linkbetween the vehicle dynamic environments calculated by the solver in the controls analysistool to the fluid flow equations solved by the CFD code.This paper describes such acoupling methodology,presents the results of a series of test cases,and compares said resultsagainst equivalent results from extensively validated tools.The coupling methodology,described herein,has proven to be highly accurate in a variety of different cases.  \n## I.Introduction\n\nThe effects of sloshing propellant on the control system of a launch vehicle are very important and cannottypically be ignored.Many different tools have been developed to study this interaction and attempt to predict themagnitude of the slosh effects.One such tool is called the Universal Controls Analysis Tool (UCAT).This tool is aMathworks MATLAB based model developed and used extensively by the Launch Services Program(LSP)at theKennedy Space Center(KSC)to analyze the performance of many launch vehicles on a mission by mission basis.Ithas the capability of including a multitude of dynamics such as structural bending,actuators,winds,gravity,aerodynamics,sensors,and propellant slosh.The Launch Services Program has developed a version of this tool formost vehicles and configurations(number of boosters,stages,and engines)used by the program.Since most of thedetails of these models are proprietary in nature,this paper will focus on a generic version of the tool with noreference to any proprietary information.  \nThe computational fluid dynamics(CFD)solver used in this study is Flow3D distributed by Flowscienceinc.It is a robust solver that is widely used in the aerospace industry.³It is a leader in free surface flow simulationssuch as water in ducts,liquid metal castings,and liquid propellant tank slosh.This code is used extensively by theLaunch Services Program to analyze fluid flow in propellant tanks and address any concerns with propellantorientation within the tanks during any point in the mission.It is also used to develop slosh parameters for themechanical analogs used in some control system simulations and is capable of simulating many different fluids,from cryogens like liquid oxygen,to storable propellants like hydrazine.  \nThe motivation for this study arose from the need for a more robust and accurate method of determining theeffects of propellant slosh on control systems with the goal of accurately predicting the location of the propellantswithin the tanks.In the past,this information was needed to evaluate the effects of propellant slosh during abruptvehicle maneuvers.Issues such as ullage collapse,wall wetting,thermal conditioning,liquid venting,controlstability,and cryogenic boil-off have all been of concern to a multitude of missions.The problem is that during theseabrupt vehicle maneuvers,the simple pendulum analog used to model propellant effects is no longer valid.By  \nreplacing the pendulum analog with a full CFD solution,the model remains valid and will not only produce vehiclecontrol response effects,but also produce accurate propellant location information.From this,all of the aforementioned issues may be resolved.  \nThis analysis was previously accomplished using a two step process.First,the controls systems engineerdetermines the appropriate acceleration environme","cbCaijpnmdnx7CQU","https://ap.wps.com/l/cbCaijpnmdnx7CQU","pdf",4182502,"English","# I. Introduction\n## II. Pendulum Analog","[{\"question\":\"Why is propellant slosh coupling important for launch vehicle control predictions?\",\"answer\":\"Sloshing propellant significantly affects the launch vehicle control system, so ignoring the interaction leads to inaccurate estimates of control response and propellant-related behavior.\"},{\"question\":\"How does the proposed CFD-and-controls coupled method improve accuracy over mechanical analogs?\",\"answer\":\"Instead of relying on mechanical analogs valid only in limited conditions, the coupling runs both solvers simultaneously so fluid forces influence the control system and the control environment feeds back into the CFD solution.\"},{\"question\":\"What limitations are associated with the pendulum analog approach?\",\"answer\":\"The pendulum analog is valid mainly for low-amplitude slosh and can break down when slosh waves become violent. It also cannot directly provide propellant location within the tank.\"}]","High Accuracy Liquid Propellant Slosh Predictions Using an Integrated CFD and Controls Analysis Interface - Research | PDF",25]