OS-T: 1600 Fluid-Structure Interaction Analysis of Piezoelectric Harvester Assembly
Product Version: Hyperworks 2021.2.1 or above
The purpose of this tutorial is to demonstrate how to carry out Fluid-Structure Interaction analysis that is, with OptiStruct nonlinear transient analysis coupling within AcuSolve fluid dynamic analysis.
In this tutorial, you will explore the possibility of using piezoelectric based fluid flow energy harvesters. These harvesters are self-excited and self-sustained in the sense that they can be used in steady uniform flows. The configuration consists of a piezoelectric cantilever beam with a cylindrical tip body (which is the structure model) which promotes sustainable, aero-elastic structural vibrations induced by vortex shedding and galloping. The structural and aerodynamic properties of the harvester alter the vibration amplitude and frequency of the piezoelectric beam and the fluid flow. As you may know, the Piezoelectric energy harvesting using fluid flow involves the mutual interaction of three distinct dynamic systems, namely the fluid, the structure and the associated electrical circuit.
Note: This tutorial is limited to study only fluid and the structure domain.
Figure 2 illustrates the fluid structural model used for this tutorial: the dimensions of the beam are shown in Figure 1 and Figure 2.
Figure 1. Schematic of the Problem
Figure 2. Various Layers of Beam
The AcuSolve fluid model (slab_dcfsi.inp) and the OptiStruct structural beam model (Slab.fem) are located in the fsi_models.zip file. Refer to Access the Model Files in the online help.
Step 1. Launch HyperWorks and Set the OptiStruct User Profile
This loads the user profile. It includes the appropriate template, macro menu, and import reader, paring down the functionality of HyperWorks to what is relevant for generating models for OptiStruct.
Step 2: Import the Model
A Select OptiStruct file browser opens.
Step 3: Set Up the Model
3.1 Create Contact Surface
A default contact surface template displays in the Entity Editor.
Figure 3. All sides of the beam except in the front
3.2 Define Nonlinear Parameters
A default NLPARM load step inputs collector template displays in the Entity Editor.
Figure 4. Create NLPARM card
See NLPARM Bulk Data Entry for more information.
Figure 5. NLPARM card
3.3 Define Transient Time Step Parameters
A default TSTEP load collector template displays in the Entity Editor.
See TSTEP Bulk Data Entry for more information.
Figure 6. TSTEP card
3.4 Define Incremental Result Output for Nonlinear Analysis
A default load step inputs collector template displays in the Entity Editor.
See NLOUT Bulk Data Entry for more information.
Figure7. NLOUT card
3.5 Define Fluid-Structure Interaction Parameters
A default FSI load collector template displays in the Entity Editor.
See FSI Bulk Data Entry for more information.
Figure 8. FSI card
3.6 Define Output Control Parameters
Figure 9. Create GLOBAL_OUTPUT_REQUEST
3.7 Create Nonlinear Transient Analysis Subcase
Figure 10. Create load step
Step 4: Modify the AcuSolve input file
Figure 11. Modify the AcuSolve input deck
Step 5: Submit the Job
Figure 12. Submit the job using ACC
If the job is successful, you will see new results files in the directory where the input decks are located in. The Slab.out file is where you will find error messages that will help you debug your input deck, if any errors are present.
The default files that will be written to your directory are:
Contains information pertaining to model progression. Logs regarding connection establishment, initial external code handshake and subsequent time step data in conjunction with exchange/stagger.
HTML report of the analysis, giving a summary of the problem formulation and the analysis results.
ASCII based output file of the model check run before the simulation begins and gives some basic information on the results of the run.
Summary of analysis process, providing CPU information for each step during the process.
HyperView compressed binary results file.
Step 6: View the Results
Using HyperView, plot the Displacement contour at 0.95 s, as shown in Figure 13.
Figure 13. View the Results