BEGIN:VCALENDAR VERSION:2.0 PRODID:-//wp-events-plugin.com//6.6.4.4//EN TZID:Asia/Jerusalem X-WR-TIMEZONE:Asia/Jerusalem BEGIN:VEVENT UID:0-438@aerospace.technion.ac.il DTSTART;TZID=Asia/Jerusalem:20170605T163000 DTEND;TZID=Asia/Jerusalem:20170605T173000 DTSTAMP:20230530T181144Z URL:https://aerospace.technion.ac.il/events/cfdquasi-steady-coupled-trim-a nalysis-of-diptera-type-flapping-wing-mav-in-steady-flight/ SUMMARY:CFD/Quasi-Steady Coupled Trim Analysis of Diptera-type Flapping Win g MAV in Steady Flight DESCRIPTION:Lecturer:Dr. Camli Badrya\n Faculty:Aerospace Engineering Depar tment\n Institute:University of Maryland\n Location:Classroom 165\, ground floor\, Library\, Aerospace Eng.\n Zoom: \n Abstract: \n Details: \n The aerodynamic phenomena that keep insect aloft are drastically different fro m that of a fixed-wing or rotary-wing based aircraft. While there is a goo d level of understanding of the principles behind insect flight\, the nuan ces in the aerodynamics are not yet fully understood to the extent where c oncepts can be translated to practical designs. Insects utilize large unst eady aerodynamic forces to hover in gusty conditions\, fly forward\, sidew ays and even perch upside down. The nature of the flow they operate in is highly viscous\, which leads to vortex formation and flow separation that is inherently unsteady. High-fidelity simulations can provide precise inst antaneous airloads at these length scales\, especially where performing ex periments can be challenging. Consequently\, computational tools can be us ed to accurately model the unsteady flowfield around flapping wings.\nFrom an engineering perspective\, it is useful to compare the performance of d ifferent flapping wing configurations (in steady forward flight or coordin ated turn) under ``trimmed'' flight conditions. Without an efficient trim algorithm\, trial-and-error based identification of the trimmed wing kinem atics is computationally expensive for any flight condition\, because the large number of simulations required makes the process practically infeasi ble. In a global sense the nature of forces produced by flapping wings clo sely resemble those on a helicopter blade\, such that an analogy can be dr awn between the two. Therefore\, techniques developed for helicopter perfo rmance calculation are adapted and applied to the flapping wing platform p articularly for analyzing steady flight. The aim of this study is\, theref ore\, to formulate a computationally efficient and robust framework to obt ain trim solutions that couples a flight dynamic model using simplified qu asi-steady (QS) wing aerodynamics to a high-fidelity CFD analysis. Such an analysis will provide the ability to incorporate the effects of detailed aerodynamic forces from CFD into the trim solution for flapping wing kinem atics for the first time.\nThe coupling process resulted in key insights\, both on the numerical and physics fronts. First\, it was shown that the c oupled trim methodology based on the QS model is capable of driving the CF D towards a stable trim solution. And in doing so\, the CFD/QS coupled str ategy is much cheaper and faster than an isolated CFD approach\, while mai ntaining the accuracy of the trimmed solution. In steady flight it was obs erved that the airloads\, thrust and power are affected by the trim parame ters\, and the CFD/QS methodology accurately accounted for these inter-dep endencies. The lift-to-power ratio versus average lift was identified as a principal efficiency metric to assess the performance of flapping-wing ve hicles for a given geometry and kinematic parameters. All of the relevant nonlinear aerodynamic interactions between the wing and its surrounding en vironment were first verified experimentally in hover and then explored fu rther in level forward flight and a coordinated turn. CATEGORIES:Seminars LOCATION:Classroom 165\, ground floor\, Library\, Aerospace Eng. END:VEVENT BEGIN:VTIMEZONE TZID:Asia/Jerusalem X-LIC-LOCATION:Asia/Jerusalem BEGIN:DAYLIGHT DTSTART:20170324T030000 TZOFFSETFROM:+0200 TZOFFSETTO:+0300 TZNAME:IDT END:DAYLIGHT END:VTIMEZONE END:VCALENDAR