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1、Oscillating Plate with Two-Way Fluid-Structure InteractionIntroductionThis tutorial includes:« Features« Overview of the Problem to Solve«Setti ng up the Solid Physics in Simulatio n (ANSYS Workbe nch)«Setti ng up the Fluid Physics and ANSYS Multi-field Setti ngs in ANSYS CFX-Pre
2、* Obta ining a Solution using ANSYS CFX-Solver Ma nager* Viewi ng Results in ANSYS CFX-PostIf this is the first tutorial you are working with, it is important to review the following topics before begi nning:«Sett ing the Worki ng Directory* Cha nging the Display ColorsUni ess you pla n on runn
3、ing a sessi on file, you should copy the sample files used in this tutorial from the in stallati on folder for your software (<CFXROOT>/examples/) to your work ing directory. This preve nts you from overwriti ng source files provided with your in stallatio n. If you pla n to use a sessi on fil
4、e, please refer to Play ing a Sessi on File.Sample files refere need by this tutorial in clude:* Oscillati ngPlate.pre* Oscillati ngPlate.agdb* Oscillati ngPlate.gtm* Oscillati ngPlate.i np1. FeaturesThis tutorial addresses the followi ng features of ANSYS CFX.ComponentFeatureDetailsANSYS CFX-PreUse
5、r ModeGeneral ModeSimulation TypeTransientANSYS Multi-fieldComponentFeatureDetailsFluid TypeGeneral FluidDomain TypeSingle DomainTurbulence ModelLaminarHeat TransferNoneOutput ControlMonitor PointsTransient Results FileBoundary DetailsWall: Mesh Motion = ANSYS MultiFieldWall: No SlipWall: AdiabaticT
6、imestepTransientANSYS CFX-PostPlotsAnimationContourVectorIn this tutorial you will lear n about:* Moving mesh* Fluid-solid in teract ion (in cludi ng modeli ng solid deformati on using ANSYS)* Running an ANSYS Multi-field (MFX) simulatio n* Post-process ing two results files simulta neously.2. Overv
7、iew of the Problem to SolveThis tutorial uses a simple oscillat ing plate example to dem on strate how to set up and run a simulation involving two-way Fluid-Structure Interaction, where the fluid physics is solved in ANSYS CFX and the solid physics is solved in the FEA package ANSYS. Coupling betwe
8、en the two solvers is required throughout the soluti on to model the in teract ion betwee n fluid and solid as time progresses, and the framework for the coupli ng is provided by the ANSYS Multi-field solver, using the MFX setup.The geometry con sists of a 2D closed cavity. A thin plate is an chored
9、 to the bottom of the cavity as show n below:An in itial pressure of 100 Pa is applied to one side of the thin plate for 0.5 sec onds in order to distort it. Once this pressure is released, the plate oscillates backwards and forwards as it attempts to regain its equilibrium (vertical) position. The
10、surrounding fluid damps the oscillations, which therefore have an amplitude that decreases in time. The CFX Solver calculates how the fluid resp onds to the moti on of the plate, and the ANSYS Solver calculates how the plate deforms as a result of both the in itial applied pressure and the pressure
11、result ing from the prese nee of the fluid. Coupli ng betwee n the two solvers is required si nee the solid deformati on affects the fluid soluti on, and the fluid solution affects the solid deformation.The tutorial describes the setup and execution of the calculation including the setup of the soli
12、d physics in Simulati on(withi n ANSYS Workbe nch) and the setup of the fluid physics andANSYS Multi-field sett ings in ANSYS CFX-Pre. If you do n ot have ANSYS Workbe nch, the n you can use the provided ANSYS in put file to avoid the n eed for Simulatio n.3. Setting up the Solid Physics in Simulati
13、on (ANSYS Workbench)This secti on describes the step-by-step defi niti on of the solid physics in Simulati on with in ANSYS Workbe nch that will result in the creation of an ANSYS in put file Oscillati ngPlate.i np. If you prefer, you can in stead use the provided Oscillati ngPlate.i np file and con
14、tinue from Sett ing up the Fluid Physics and ANSYS Multi-field Setti ngs in ANSYS CFX-Pre.Creating a New Simulatio n1. If required, lau nch ANSYS Workbe nch.2. Click Empty Project. The Project page appears displaying an unsaved project.3. Select File > Save or click Save butt on.4. If required, s
15、et the path location to a different folder. The default location is your working directory. However, if you have a specific folder that you want to use to store files created during this tutorial, change the path.5. Un der File name, type Oscillat in gPlate.6. Click Save.7. Under Link to Geometry Fi
16、le on the left hand task bar click Browse. Select the provided file OscillatingPlate.agdb and click Open.8. Make sure that OscillatingPlate.agdb is highlighted and click New simulation from the left-ha nd taskbar.Creati ng the Solid Material1. When Simulatio n ope ns, expa nd Geometry in the project
17、 tree at the left hand side of the Simulatio n win dow.2. Select Solid, and in the Details view below, select Material .3. Use the arrow that appears next to the material name Structural Steel to select NewMaterial .4. When the Engineering Data window ope ns, right-click New Material from the tree v
18、iewand ren ame it to Plate.OE ngrieiiig D-al-s-占 ClgtLH H-OlCdfatii'ngFLHrX_j|2|4 PlMft % ShudijMl 咅 W浒P 窃Ah - 5*np(n?d 二 jLOAd HrftC#Mh& IO1PxopE冲1 Iwmai 匚Cl WAn-TLLi专RCilM HiMi!卫E >leot r mnanEliLAdd-'Aemove iPiaperiieRiFeme丄.1Fl 任耐Q OlhtH m5. Enter 2.5e06 for Young's Modulus ,
19、0.35 for Poisson's Ratio and 2550 for Density.Note that the other properties are not used for this simulati on, and that the un its for these values are implied by the global un its in Simulati on.6. Click the Simulation tab near the top of the Workbench window to return to the simulatio n.Basic
20、 An alysis Sett ingsThe ANSYS Multi-field simulation is a transient mechanical analysis, with a timestep of 0.1 s and a time duration of 5 s.1. Select New Analysis > Flexible Dynamic from the toolbar.2. Select An alysis Setti ngs from the tree view and in the Details view below, set Auto Time Ste
21、pping to Off.3. Set Time Step to 0.1.4. Under Tabular Data at the bottom right of the window, set End Time to 5.0 for the Steps = 1 sett in g.Inserting LoadsLoads are applied to an FEA an alysis as the equivale nt of boun dary con diti ons in ANSYS CFX. In this sect ion, you will set a fixed support
22、, a fluid-solid in terface, and a pressure load.Fixed SupportThe fixed support is required to hold the bottom of the thin plate in place.1. Right-click Flexible Dynamic in the tree and select Insert > Fixed Support from the shortcut menu.2. Rotate the geometry using the Rotatebutt on so that the
23、bottom (low-y) face of thesolid is visible, then select Face 囲 and click the low-y face.That face should be highlighted to in dicate selecti on.3. Ensure Fixed Support is selected in the Outline view, then, in the Details view, select Geometry and click 1 Face to make the Apply butt on appear (if n
24、ecessary). Click Apply to set the fixed support.Fluid-Solid InterfaceIt is n ecessary to defi ne the regi on in the solid that defi nes the in terface betwee n the fluid in CFX and the solid in ANSYS. Data is excha nged across this in terface duri ng the executi on of the simulatio n.1. Right-click
25、Flexible Dynamic in the tree and selectInsert > Fluid Solid Interface fromthe shortcut menu.2. Using the same face-selection procedure described earlier, select the three faces of the geometry that form the in terface betwee n the solid and the fluid (low-x, high-y and high-x faces) by holding do
26、wn <Ctrl> to select multiple faces. Note that this load is automatically give n an in terface nu mber of 1.Pressure LoadThe pressure load provides the in itial additi onal pressure of 100 Pa for the first 0.5 sec onds of the simulati on .It is defi ned using a step function.1. Right-click Flex
27、ible Dyn amic in the tree and select Insert > Pressure from the shortcut menu.2. Select the low-x face for Geometry.3. In the Details view, select Magnitude , and using the arrow that appears, select Tabular (Time).4. Under Tabular Data , set a pressure of 100 in the table row corresponding to a
28、time of 0.Note: The units for time and pressure in this table are the global units of s and Pa, respectively.5. You now n eed to add two new rows to the table. This can be done by typi ng the new timeand pressure data into the empty row at the bottom of the table, and Simulation will automatically r
29、e-order the table in order of time value. Enter a pressure of 100 for a time value of 0.499, and a pressure of 0 for a time value of 0.5.i Tabular DataStepsTime阳"Free：jij re |110100 J210499100310.50.4150.This gives a step function for pressure that can be see n in the chart to the left of the t
30、able.Writi ng the ANSYS In put FileThe Simulation settings are now complete. An ANSYS Multi-field run cannot be launched from with in Simulati on, so the Solve butt ons cannot be used to obta in a soluti on.1. In stead, highlight Solution in the tree, select Tools > Write ANSYS Input File and cho
31、ose to write the solution setup to the file OscillatingPlate.inp.2. The mesh is automatically gen erated as part of this process. If you want to exam ine it, select Mesh from the tree.3. Save the Simulation database, use the tab near the top of the Workbench window to return to the Oscillating Plate
32、 Project tab, and save the project itself.4. Setting up the Fluid Physics and ANSYS Multi-field Settings in ANSYS CFX-PreThis section describes the step-by-step definition of the flow physics and ANSYS Multi-field settings in ANSYS CFX-Pre.Playing a Session FileIf you want to skip past these instruc
33、tions and to have ANSYS CFX-Pre set up the simulation automatically, you can select Session> Play Tutorial from the menu in ANSYS CFX-Pre, then run the session file: OscillatingPlate.pre. After you have played the session file as described in earlier tutorials under Playing the Session File and S
34、tarting ANSYS CFX-Solver Manager, proceed to Obtaining a Solution using ANSYS CFX-Solver Manager.Creating a New Simulation1. Start ANSYS CFX-Pre.2. Select File > New Simulation .3. Select General and click OK.4. Select File > Save Simulation As.5. Under File name, type OscillatingPlate.6. Clic
35、k Save.Importing the Mesh1. Right-click Mesh and select Import Mesh .2. Select the provided mesh file, OscillatingPlate.gtm and click Open.Note： The file that was just created in Simulation, OscillatingPlate.inp, will be used as an input file for the ANSYS Solver.Setting the Simulation TypeA transie
36、nt ANSYS Multi-field run executes as a series of timesteps. TheSimulation Typetab is used both to enable an ANSYS Multi-field run and to specify the time-related settings for it (in the External Solver Coupling settings). The ANSYS input file is read by ANSYS CFX-Pre so that it knows which Fluid Sol
37、id Interfaces are available.Once the timesteps and time duration are specified for the ANSYS Multi-field run (coupling run), ANSYS CFX automatically picks up these settings and it is not possible to set the timestep and time duration independently. Hence the only option available for Time Duration i
38、s Coupling Time Duration, and similarly for the related settings Time Step and Initial Time.1. Click Simulation Type2. Apply the follow ing sett ingsTabSettingValueBasicSettingsExternal Solver Coupling > OptionANSYS MultiFieldExternal Solver Coupling > ANSYS Input FileOscillatingPlate.inpaCoup
39、ling Time Control > Coupling Time Duration > TotalTime5 sCoupling Time Control > Coupling Time Steps > OptionTimestepsCoupling Time Control > Coupling Time Steps > Timesteps0.1 sSimulation Type > OptionTransientSimulation Type > Time Duration > OptionCoupling Time Duration
40、Simulation Type > Time Steps > OptionCoupling Time StepsSimulation Type > Initial Time > OptionCoupling Initial Time呵 This file is located in your working directory.3. Click OK.Note： You may see a physics validation message related to the differenee in the units used inANSYS CFX-Pre and
41、the units con tai ned withi n the ANSYS in put file. While it is importa nt toreview the units used in any simulation, you should be aware that, in this specific case, the message is not crucial as it is related to temperature un its and there is no heat tran sfer in this case. Therefore, this speci
42、fic tutorial will not be affected by the physics message.Creat ing the FluidA custom fluid is created with user-specified properties.1. Click Material 因.2. Set the n ame of the new material to Fluid.3. Apply the follow ing sett ingsTabSettingValueBasic SettingsOptionPure SubstanceThermodynamic State
43、(Selected)Thermodynamic State > Thermodynamic StateLiquidMaterial PropertiesEquation of State > Molar Mass1 kg kmolA-1TabSettingValueEquation of State > Density1 kg mA-3Transport Properties > Dynamic Viscosity(Selected)Transport Properties > Dynamic Viscosity > Dynamic Viscosity0.2
44、 Pa s4. Click OK.Creat ing the Doma inIn order to allow the ANSYS Solver to com muni cate mesh displaceme nts to the CFX Solver, mesh moti on must be activated in CFX.1. Right click Simulation in the Outline tree view and ensure that Automatic Default Domain is selected. A domain named Default Domai
45、n should now appear under the Simulati on bran ch.2. Double click Default Doma in and apply the followi ng sett ingsTabSettingValueGeneral OptionsFluids ListFluidDomain Models > Pressure > Reference Pressure1 atmDomain Models > Mesh Deformation > OptionRegions of Motion SpecifiedFluid Mo
46、delsHeat Transfer > OptionNoneTurbulence > OptionNone (Laminar)3. Click OK.Creati ng the Boun dary Con diti onsIn addition to the symmetry conditions, another type of boundary condition corresponding with the in teract ion betwee n the solid and the fluid is required in this tutorial.Fluid Sol
47、id Exter nal Boun daryThe in terface betwee n ANSYS and CFX is defi ned as an exter nal boun dary in CFX that has its mesh displacement being defined by the ANSYS Multi-field coupling process.When an ANSYS Multi-field specification is being made in ANSYS CFX-Pre, it is necessary to provide the name
48、and number of the matching Fluid Solid Interface that was created in Simulati on. Since the in terface nu mber in Simulati on was 1, the n ame in questi on is FSIN_1. (If the in terface nu mber had bee n 2, the n the n ame would have bee n FSIN_2, and so on.)On this bou ndary, CFX will se nd ANSYS the forces on the in terface, and ANSYS will sendback the total mesh displacement it calculates given the forces passed from CFX and the other defi ned loa