ANSYS R13 Missile FSI Example

ANSYS R13

External Aerodynamics and

One-Way FSI Modeling

Hawk Missile Example Simulation

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Presented by: Michael Showalter April 6, 2011

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Presentation Overview • Analysis Tools

• Hawk Missile Geometry

• Computational Meshes (Fluid & Solids)

• Model Definition

• CFD Fluids Results

• One-Way Pressure Coupling to ANSYS Mechanical

• External Data Set Capability (new R13)

• Questions and Discussion

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ANSYS Suite of Analysis Tools

• ANSYS Workbench: – DesignModeler (geometry creation)

– ANSYS Meshing (mesh generation)

– FLUENT (CFD - fluids solver)

– ANSYS (thermal & structural analyses)

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Missile Geometry

Hawk Missile Body

Virtual Wind Tunnel

Farfield Flow Inlet

Farfield Flow Outlet

Angle of Attack 20o

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Missile Geometry (zoom)

Half Symmetry

Farfield Flow Inlet

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FLUENT Computational Mesh

Mesh Refinement Around the Missile Body

Volume Mesh, CutCells (2.6M Total Elements)

Flow Inlet

Flow Outlet

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FLUENT Computational Mesh

Fluid Region CutCells with

B.L. Mesh

Boundary Layer

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Computational Model Definition

• Steady state flow conditions (i.e. not changing with time)

• Three-dimensional model

• Linear elastic structural analysis

• Turbulent flow (SST k/omega model)

• Fluid: air, ideal gas

• Air inflow/outflow conditions:

– Velocity = Mach 2.5, sea level, AoA 20o

– Temperature = 70 °F

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ANSYS Workbench

One-Way FSI (Coupled) CFD, Pressure & Structural

Simulation

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Velocity Vectors

Mach 2.5, AoA 20o

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Pressure Contours (Pa)

Air Flow

Mach 2.5, AoA 20o

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Transparent Volume of Velocity

Mach 2.5, AoA 20o

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Streamlines colored by Pressure (Pa)

Mach 2.5, AoA 20o

Mapping Project Page The following project schematic illustrates one-way load mapping from FLUENT to Mechanical.

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Hawk Missile M=0.9 Hawk Missile M=2.5

External Data Method

New at R13 is the ability to import loads from ANSYS tools, third party software, or even user defined loading. The loading needs to be in a delimited format, i.e. Excel .csv file. The data is entered using an External Data component system from the project schematic and then linked to the appropriate analysis. In the below example, pressures loads were extracted from FLLUENT and mapped to the Mechanical model. The next slide illustrates the external data setup.

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Hawk Missile M=0.9 Hawk Missile M=2.5

Enter line number where data starts

Format type: delimited

Delimiter type: Comma

*.csv File Name Use to browse to *.csv file location

Entered a Description (optional)

Specified data type and units for four columns imported

Added a data indentifier for

Clipped Pressure (optional)

Preview of portion of data to make

sure import correct

External Data Importing Overview

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External Data Method Pressure Mapping

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Mach 2.5, AoA 20o

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Fixed Support at Nosetip, Inertial Relief

Contours of Total Deformation

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Mach 2.5, AoA 20o

Contours of Equivalent Stress

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Mach 2.5, AoA 20o