8/15/2019 Kiran Research Poster

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Dr. Kiran RameshAerospace Sciences

Division

Low-order Modelling Of Unsteady Aerodynamics and Applications

University of Glasgow, charity number

Features of Unsteady Flows

Complex wakestructures

Flow separation Leading-edge vortex (LEV)formation

Augmented discrete-vortex method (UNSfow)

• Airfoil moves along anyarbitrary time#varying path

• At each time#step, a vorte$ isshe% from the trailing#e%ge tomo%el the wa&e

• '(hin#airfoil theory)formulation is use% to solvefor vorticity an% pressure onairfoil

• Criteria base% on theory are%evelope% to %etermine when*ow separation an% +-formation woul% occur

• At each time#step, thesecriteria are teste%

• f the criteria test positive,*ow separation an% +-formation are simulate%through release of %iscretevortices

Illustration• /otion 0grey line1 2

Smooth pitch#up to 3%eg an% pitch %own to4ero, about trailing#e%gepivot

• U5Sow is compare%against C6D metho%

• 7 instances of +-formation are present inthis case

      L      i      f      t

U5S*ow

U5S*ow

CFD U5Sow

      D     r     a     g

Advantages• Solves for forces on the airfoil as well as

*ow8el% vorticity• Average simulation time is less than "

min9• /etho% is gri%#free• /ore intuitive than tra%itional C6D

metho%s• :nly the %ominant physics is mo%elle%• 5ot base% on any empirical %ata or curve

8ts

Applications and current

research

esign of !apping!yers• ;io#inspiration from insect

*ight• ect topitch oscillations, e$cee% the staticstall angle

• Results in +- which becomesunstable an% %etaches from theairfoil, resulting in violentvibrations an% structural failure

• Current metho% is i%eal to stu%yrotor %ynamic stall as it is ane$tremely e$pensive problem for

conventional C6D

Fluid-structure

interaction ;oeing concept

5ASA