{"672464":{"#nid":"672464","#data":{"type":"event","title":"MS Proposal by Rithvik Nagarajan","body":[{"value":"\u003Cp\u003ERithvik Nagarajan\u003Cbr \/\u003E\r\n(Advisor: Prof. Lightsey)\u003Cbr \/\u003E\r\nwill propose a master\u2019s thesis entitled,\u003Cbr \/\u003E\r\nNumerical Studies on the Determination and Prevention of Roll Resonance in Liquid Sounding Rockets\u003Cbr \/\u003E\r\nOn\u003Cbr \/\u003E\r\nThursday, February 1 at 11:00 a.m.\u003Cbr \/\u003E\r\nWeber Space and Technology Building 304\u003Cbr \/\u003E\r\nAbstract\u003Cbr \/\u003E\r\nSounding rockets are suborbital vehicles designed to carry scientific payloads and perform\u0026nbsp;\u003Cbr \/\u003E\r\nexperiments in the upper atmosphere. Recently, there has been a focus on reusable liquid sounding\u0026nbsp;\u003Cbr \/\u003E\r\nrockets to allow faster launch rates and lower costs per mission. Fin-stabilized sounding rockets\u0026nbsp;\u003Cbr \/\u003E\r\ntend to be designed with high length-to-diameter ratios for drag optimization. This leads to a\u0026nbsp;\u003Cbr \/\u003E\r\nsusceptibility in roll-yaw resonance, where the vehicle spins close to the pitch natural frequency.\u0026nbsp;\u003Cbr \/\u003E\r\nPrevious studies have shown the vehicle can exhibit abnormal rolling and yawing motion beyond\u0026nbsp;\u003Cbr \/\u003E\r\npredictions by linear theory. These phenomena are referred to as roll lock-in and catastrophic yaw\u0026nbsp;\u003Cbr \/\u003E\r\nrespectively. These effects can destabilize the rocket and induce high structural loads.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cbr \/\u003E\r\nThis research investigates the susceptibility and consequences of roll lock-in and catastrophic yaw\u0026nbsp;\u003Cbr \/\u003E\r\non liquid sounding rocket designs using a comprehensive a 6DOF numerical model. Non-linear\u0026nbsp;\u003Cbr \/\u003E\r\ncombustion, vehicle aeroelasticity, configurational asymmetries, and non-linear aerodynamics are\u0026nbsp;\u003Cbr \/\u003E\r\nincorporated into this model with Monte Carlo variables. Previous off-nominal Georgia Tech sounding\u0026nbsp;\u003Cbr \/\u003E\r\nrockets are studied with respect to roll resonance to validate this model. This numerical approach\u0026nbsp;\u003Cbr \/\u003E\r\nis used to validate a well- known space-shot sounding rocket design and assess mission failure\u0026nbsp;\u003Cbr \/\u003E\r\nlikelihood. The findings reveal a high susceptibility to roll resonance, prompting the proposal of\u0026nbsp;\u003Cbr \/\u003E\r\na roll control scheme that takes advantage of liquid rocket pressurized gas. Four attitude control\u0026nbsp;\u003Cbr \/\u003E\r\nthrusters are fired in pairs, implementing a bang-bang roll control scheme tailored for liquid\u0026nbsp;\u003Cbr \/\u003E\r\nsounding rockets with elevated roll resonance risk. This research analyzes the effectiveness of the\u0026nbsp;\u003Cbr \/\u003E\r\ncontrol system in mitigating roll resonance issues.\u003Cbr \/\u003E\r\nCommittee\u003Cbr \/\u003E\r\n\u2022 \u0026nbsp;Prof. Glenn Lightsey \u2013 School of Aerospace Engineering (advisor)\u003Cbr \/\u003E\r\n\u2022 \u0026nbsp;Prof. Jonathan Rogers \u2013 School of Aerospace Engineering\u003Cbr \/\u003E\r\n\u2022 \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;f Aerospace Engineering\u003Cbr \/\u003E\r\n\u0026nbsp;\u003C\/p\u003E\r\n","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003ENumerical Studies on the Determination and Prevention of Roll Resonance in\u003Cbr \/\u003E\r\nLiquid Sounding Rockets\u003C\/p\u003E\r\n","format":"limited_html"}],"field_summary_sentence":[{"value":"Numerical Studies on the Determination and Prevention of Roll Resonance in Liquid Sounding Rockets"}],"uid":"27707","created_gmt":"2024-01-25 16:56:01","changed_gmt":"2024-01-25 16:56:01","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2024-02-01T11:00:00-05:00","event_time_end":"2024-02-01T12:00:00-05:00","event_time_end_last":"2024-02-01T12:00:00-05:00","gmt_time_start":"2024-02-01 16:00:00","gmt_time_end":"2024-02-01 17:00:00","gmt_time_end_last":"2024-02-01 17:00:00","rrule":null,"timezone":"America\/New_York"},"location":"Weber Space and Technology Building 304","extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"166866","name":"MS Proposal"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}