DOI: 10.5281/zenodo.7256436
title: Data set for bionic simulation of double clap-and-fling wing mechanism with SPH FSI method

description: Data set containing the rigid-body based flapping wing models coupled with smoothed particle hydrodynamics (SPH), by means of DualSPHysics version 5.0 and Project Chrono.
These models are part of the paper:

Yanwei Zhang, Zhonglai Wang, Saullo G. P. Castro. Bionic simulation of double clap-and-fling wing mechanism with SPH FSI method. EngXriv Preprint, 2022. DOI: 10.31224/2652
File "simulations.zip" contains the simulation files.
File "DualSPHysics_v5.0.zip" contains the compiled DualSPHysics software.
Procedure to run the simulations on a Windows machine:

Working directory: .\simulations\flappingwing\case01
Step 1: Obtain rigid bodies by modeling of SOLIDWORKS and Macro command of FreeCAD (e.g. external_wing111.stl)
Step 2: Run ".bat" file (e.g. flapping01.bat) to start simulation and force acquisition
Step 3: Revise ".bat" and ".xml" (e.g. flapping01.bat and flapping01_Def.xml)to adapt to the next case. If required, change the model and Macro command of step 1. Common modification items:
<geometry>-<definition> 
<floatings>- <floating><angularvel> 
<floatings>- <floating><property> 
<properties>-<propertyfile> 
<initials> 
<execution>-<special>-<chrono> 
<execution>-<special>-<inout> 
<parameters> 

Step 4: Run "Filter.m" to handle force data by filters. Step 5: Compare forces of all cases. PS: Other files are revised function files derived from DualSPHysics 5.0.
 
Abstract: Three-dimensional numerical simulations of flexible flapping wings basedon the fluid-structure interaction in biological and bioinspired flow have become avibrant and challenging research topic. The present paper focuses on a parametricstudy of the aerodynamic performance of a bionic flexible clapping wing. The proposedmodel deforms the wing in spanwise and chordwise directions based on the six rigidbodies connected along the wing veins using ball links and springs. Unsteady effects offlapping wing micro air vehicles with a double clap-fling configuration are investigatedusing an air-solid interaction model based on smoothed particle hydrodynamics andrigid multi-body dynamics. A validation experiment determined the convergenceconditions and computational model accuracy. The proposed numerical model isevaluated in terms of flexible variation law and aerodynamic performance. The resultsindicate that the flapping frequency, angle of attack, and wind velocity significantlyinfluence the lift. Furthermore, increasing the frequency will monotonically expandthe maximum and time-averaged lift curve values. When the angle of attack is lessthan 30 ◦, the influence on the time-averaged and maximum lift is proportional to theangle of attack. When the angle of attack is larger than 45 ◦, a stall-like conditionis detected. To broaden the applicability of the present findings, a dimensionlessparameter, reduced frequency, is defined, and its influence on the maximum and time-averaged lift is investigated. This parametric study shows that as the reduced frequencyincreases, the maximum and time-averaged lift increases and then decreases. Thepresent study could reach a modeling framework that better explains the clappingwing aerodynamics.