SIMULASI INTERAKSI FLUIDA DAN STRUKTUR SAYAP KEPAK BURUNG

NUMERICAL SIMULATION OF FLEXIBLE WING OF HALE UAV USING TWO-WAY FLUID STRUCTURE INTERACTIONAdvisor : Dr. Ing Mochammad Agoes MoelyadiBUYUNG JUNAIDIN23612002September 18th,2014Department of Aeronautics and AstronauticsINSTITUT TEKNOLOGI BANDUNGOUTLINEINTRODUCTIONRESEARCH BACKGROUNDRESEARCH OBJECTIVESPROBLEM SCOPE

SIMULATION RESULTSVALIDATION 1AERODYNAMICS CHARACTERISTICSFLOW PHYSICSAERODYNAMIC DAMPINGSTRUCTURAL RESPONSESVALIDATION 2FSI SIMULATIONCOMPUTATIONAL APPROACHWING MODELMULTI-FILED SIMULATIONSTRUCTUREFLUIDCOUPLING PROCESSCONCLUSIONCONCLUSIONFUTURE WORK

INTRODUCTIONRESEARCH BACKGROUND

INTRODUCTIONRESEARCH BACKGROUND

Low-cost alternative space missions

INTRODUCTIONRESEARCH BACKGROUND

Extreme altitude & long enduranceHigh aerodynamic efficiency & Light weigh structure

High aspect ratio wingFlexible wingFSI PhenomenonINTRODUCTIONRESEARCH OBJECTIVESTo simulate fluid structure interaction on flexible HALE wingTo investigating aerodynamic characteristics of flexible HALE wingTo predict structural behaviour of HALE wingTo study effect of wing material characteristics to the structural response of HALE wingINTRODUCTIONPROBLEM SCOPESimple structure wing (solid structure without ribs and spars) as structural wing modelThe earth gravity acceleration is not applied in structural calculationUse two-way FSI method to simulate the flexible HALE wing for aerodynamic characteristics and structural responseFSI SIMULATIONCOMPUTATIONAL APPROACH

Free streamFlexible wingTwo-way FSICantilever wingFSI SIMULATIONWING MODELParameterDesign modelC (m)0.4 (root and tip inner wing)0.4 (root outer wing), 0.25 (tip outer wing)y (m)4.2 (inner wing)1.5 (outer wing)Wing airfoilEMX-07 (deg) 0.0 (inner wing)4.2 (outer wing at 0.25C) (deg)0.0 (inner wing)9.8 (outer wing)Wing specificationWing material

Wing modelMaterialsCharacteristicsnE (Gpa) (kg/m3)Steel0.302007850A0.3020B0.302C0.402D0.492Youngs Modulus (E)

Poissons Ratio ()

the negative ratio of transverse to axial strain

measure of the stiffness of an elastic materialFSI SIMULATIONSIMULATION SETUP

CouplingFSI SIMULATIONANSYS SETUP

Auto-meshPhysical ParametersValuesTemperature248.5 oKDensity7850 kg/m3MaterialSteelYoungs modulus200E+11 N/m2Poissons ratio0.3FSI SIMULATIONCFX SETUP

InletSymmetryOutletWallFarfieldStructured hexa type meshANSYS ICEMPhysical ParametersValuesStatic Temperature248.5 oKStatic Pressure46562 N/m2Density0.653 kg/m3Free stream velocity17.88 m/sTime step0.025 sTotal time60 sTurbulence modelSSTFSI SIMULATIONCOUPLING PROCESS

Strong coupling of Two-way FSIFSI SIMULATIONMULTI-FIELD SIMULATION

StructuralFluid

Coupling ProcessResultsSIMULATION RESULTSVALIDATION 1Number of elementCL (%)CD (%)4427220.130.0105254310.12-6.30.008-20.46255670.11-5.70.006-25.07236630.11-3.10.005-10.89054750.11-2.90.005-13.2Grid Independence studyGrid Independence study plotsSIMULATION RESULTSAERODYNAMIC CHARACTERISTICSDownward motionDownward motionminmaxminminmaxmaxmaxmaxmiddlemiddlemiddlemiddle17SIMULATION RESULTSFLOW PHYSICS

Upward motionLE, 0.7ydownwashfree stream-

downwashupwardSIMULATION RESULTSFLOW PHYSICS

Downward motionLE, 0.7yUpwashfree stream+

upwashdownwardSIMULATION RESULTSFLOW PHYSICSt=25s, 0.7yt=25s

SIMULATION RESULTSAERODYNAMIC DAMPING

StructuremotionFluidenergy transferred from structure to the fluidenergy dissipated by fluidSIMULATION RESULTSAERODYNAMIC DAMPINGAerodynamic damping ratio

FSI simulationStructural simulationt=10st=10sMaterialsSteel (E=200,n=0.3)0.013A (E=20,n=0.3)0.026B (E=2,n=0.3)0.075C (E=2,n=0.4)0.073D (E=2,n=0.49)0.072d logarithmic decrementx0 amplitude of the first cyclexn amplitude of the nth cycle damping ratioSIMULATION RESULTSSTRUCTURAL RESPONSESStructural responsesMaterialsSteel(E=200,n=0.3)A(E=20,n=0.3)B(E=2,n=0.3)C(E=2,n=0.4)D(E=2,n=0.49)max (m)0.0050.0470.4260.4230.419max(GPa)2.412.362.152.232.42fd (Hz)1.00.30.10.10.1Structural resultsSIMULATION RESULTSVALIDATION 2Results comparison for z-displacementMaterialsANSYS simulation (m)Analytical solution (m) (%)Steel (E=200,=0.3)2.373e-032.295e-033.4A (E=20,n=0.3)2.430e-022.295e-025.8B (E=2,n=0.3)2.408e-012.295e-014. 9Assuming the wing as a cantilever beam, maximum displacement of the beam is calculated using energy method (Castiglianos theorem)Simulations of flexible HALE wing using two-way FSI have been done with simplify the simulation

Unsteady simulation results shows that:Lift coefficient increases and drag coefficient decreases with decreasing of Youngs modulus during downward motion and vice versa.Lift coefficient increases and drag coefficient decreases with increasing of Poissons ratio during downward motion and vice versa.Effect of variation of Poissons ratio to the increment and decrement of lift coefficient and drag coefficient is not as much as Youngs modulus effect.CONCLUSIONCONCLUSION25Simulation results show that damping is only produce by fluid, aerodynamic damping. Decreasing in Youngs modulus and/or Poissons ratio makes increment of damping ratio

Structure results shows that:Decreasing of Youngs modulus makes decrement of stresses and frequencies and increment of deformationIncreasing of Poissons ratio makes increment of stresses and decrement of deformation. Poissons ratio gives not significant influence to the frequency.CONCLUSIONCONCLUSION26CONCLUSIONDevelop wing model which representing the real wing and applying the composite material

Simulate fluid structure interaction for whole part of HALE UAV

Simulate fluid structure interaction of HALE UAV with adding the propellers effect

Investigate the effect of propellers on aerodynamic characteristics and structural behaviourFUTURE WORKThank you

ENERGY METHOD

Example:

STRRONG COUPLINGWEAK COUPLINGFLUIDSTRUCTUREMATRIX COUPLINGCOUPLING SYSTEM

Weak Coupling & Strong Coupling