Simulation of Turbulent Flow around an Airfoil57:020 Mechanics of Fluids and Transfer ProcessesCFD PRELAB 22. Simulation Design4. ExercisesSimulation of Turbulent Flow around an AirfoilSimulation of Turbulent Flow around an Airfoil 57:020 Mechanics of Fluids and Transfer ProcessesCFD PRELAB 2By Tao Xing and Fred SternIIHR-Hydroscience & EngineeringThe University of IowaC. Maxwell Stanley Hydraulics LaboratoryIowa City, IA 52242-15851. PurposeThe Purpose of CFD PreLab 2 is to simulate turbulent flow around Clarky airfoil following “CFD process” by an interactive step-by-step approach. Students will have “hands-on” experiences using FlowLab to compute pressure, lift and drag coefficients using both viscous and inviscid models. Students will validate simulation results with EFD data measured at EFD Lab 3, analyze the differences and possible numerical errors, and present results in Lab report.2. Simulation Design1Flow chart for ISTUE teaching module for airfoil flow (red color illustrates theoptions you will use in this CFD PreLab 2)GeometryPost-processingReportPhysicsMeshContoursVectorsStreamlinesSolveIterationsConver-gent.LimitPrecisionsSingleDoubleNumerical Schemes1st order2nd orderQUICKSteady/Unsteady?CoarseMediumFineAutomaticManualStructuredUnstruct-ured BoundaryConditionsFlow PropertiesViscousModelsOne Eq.Two Eq.Density and viscosityLaminarTurbulentInviscidSAk-ek-wHeat Transfer?Incompress-ible?InitialConditionsClarkyNACA12LS(1) 0417Import ProfileChord lengthAngle of attackSelect domainSelect geometryWall shear stressSkin friction FactorXY plotsVerification and validationCoefficient of liftCoefficient of dragResidualsPressure coef. Distri.Shear stress Distri.Airfoil Y plusIn EFD Lab 3, you have conducted experimental study for turbulent flow around a ClarkY airfoil (Re=300,000) for two angles of attack 0 and 16 degrees. The pressure on the foil surface you have measured will be used for CFD PreLab 2. In CFD PreLab 2, simulation will be conducted under the same conditions ofEFD Lab 3 (geometry, Reynolds number, fluid properties) at angle of attack 0 degree using both viscous and inviscid models. Simulation results will be validated by your own EFD data.The problem to be solved is turbulent flow around the ClarkY airfoil with angle of attack ()In the figure above, C is the chord length of the airfoil,  is the angle of attack, and Rc is the radius of the“O” domain.3. CFD ProcessStep 1: (Geometry)Choose “ClarkY” airfoil and “O type” domain, input the chord length of the foil and angle of attack 0 degree.1. Select Geometry (Clarky)22. Select domain (O type)3. Chord length (0.3048 m)4. Angle of attack (0)5. Mesh type (Map)6. Circle Radius Rc (6m)Click <<Create>><<Next>>.Step 2: (Physics)(1). With or without Heat Transfer?Since we are not dealing with the thermal aspects of the flow, like heat transfer, etc., switch the <<HeatTransfer >> button OFF, which is the default setup.(2). IncompressibleUse “Incompressible”. “Compressible” option is not available for current template.(3). Flow PropertiesUse the air properties at the room temperature when you conducted EFD Lab3 and click <<OK>>. Youcan use the following website to calculate air properties from the temperature:http://www.mhtl.uwaterloo.ca/old/onlinetools/airprop/airprop.htmlThe values in the figure above are for 24° temperature.3NOTE: viscosity used in FlowLab is the dynamic viscosity (kg m s�), NOT kinematic viscosity (2m s)(4). Viscous Model For turbulent flow simulations, choose turbulent model (k-e). For Inviscid flows, choose “inviscid” andclick <<OK>>.(5). Boundary ConditionsAt “Inlet”, we use constant pressure and constant velocity. Inlet velocity should be computed from the EFDdata reduction sheet and could be different from 15 m s. Use default values for turbulent quantities “k” and“e”.At “Outlet”, FlowLab uses magnitude for pressure and zero gradients for axial and radial velocities. Input“0” for the Gauge pressure and click <<OK>>.4TurbulentInviscidOn “Airfoil”, if flow is turbulent, FlowLab uses no-slip boundary conditions for velocities and zero-pressuregradient. Turbulent quantities k and e are also specified to be zero. If flow is inviscid, then zero gradient isused for pressure and certain boundary conditions (not discussed in this lab due to its complexity) are usedfor velocities. Read all the values and click <<OK>>(6). Initial ConditionsUse the default setup for initial conditions.5TurbulentInviscidTurbulentInviscidAfter specifying all the above parameters, click <<Compute>> button and FlowLab will automaticallycalculate the Reynolds number based on the inlet velocity and airfoil chord you entered. Click <<Next>>. This takes you to the next step, “Mesh”. Step 3: (Mesh)For CFD PreLab 2, use “Automatic” meshing and “Medium” mesh. Click <<Create>>, The meshgenerated will be displayed in the graphic window. NA and NC are the numbers of grid points on the airfoilsurface and radial direction, respectively. 6InviscidTurbulentStep 4: (Solve)Specify the iteration number and convergence limit to be 2000 and 10-5, respectively. Choose “DoublePrecision”, “2nd order” for numerical schemes, and “New” calculation. Click <<Iterate>>, FlowLab will7fire the XY plot for residuals that is dynamically updated during the calculation. Whenever you see thewindow, “Solution Converged”, click <<OK>>.Step 5: (Reports)“Reports” first provides you the information on “wall shear stress”, “skin friction factor”, “coefficient oflift”, and “coefficient of drag”. XY plot provide plots for “residuals”, “pressure distribution”, “pressureCoefficient”, and “Shear Stress Distribution”, etc. In this Lab, only XY plots for “residuals” and “pressurecoefficient” are required.“XY Plots” provides the following options:To import the EFD data on top of the above CFD results, just click <<File>> button and use the browse button to locate the data file you need and click <<Import>>. Details have been described in previous CFD PreLab 1 for laminar pipe flow.8In this Lab: 1. EFD data for pressure coefficient distribution should be created in your folder under H: \myflowlab\SESSION-NAME\*.xy” (Example: H: \myflowlab\prelab2\pressure-EFD.xy)The following figure is an example:Step 6: (Post-processing)Use the “contour”, “vector”