Aerodynamic Performance of a Flapping Wing Inspired by Bats

2020 ◽  
Vol 899 ◽  
pp. 42-49
Author(s):  
Shafiq Suhaimi ◽  
Solehuddin Shuib ◽  
Hamid Yusoff ◽  
A. Halim Kadarman
Keyword(s):  
Cfd Simulation ◽  
Design Method ◽  
Aerodynamic Performance ◽  
Flapping Wing ◽  
Wing Shape ◽  
Element Analysis ◽  
Minimum Drag ◽  
Computational Fluid Dynamics Cfd ◽  
Stall Angle ◽  
Bat Wing

Bio-inspiration is a design method where natural observation was used to solve a mechanical problem. In this study, a bio-inspiration meth-od was used to design a flapping wing for a Micro Air Vehicle (MAV) that is inspired by bat wings. The objective of this study is to study the aerodynamic performance of a flapping wing based on bat wings at different angles of attack. This is done using Computational Fluid Dynamics (CFD) simulation where the aerodynamic performance a wing derived from a natural bat wing shape was studied. The wing was generated by tracing the wing shape of a bat wing and the shape was generalized to produce the wing shape. In the simulation, a 2-way Fluid Structure Interaction (FSI) method was used where a Finite Element Analysis (FEA) solver was coupled with a CFD solver to simulate the wing during flapping flight. The flight condition was set at 1 m/s flight speed at a flapping frequency of 2.5Hz. From the results, it was shown that the wing has a zero-lift angle at 0o and a stall angle at 16o. It is also shown that the wing has a minimum drag angle at 3o and a maximum aerodynamic efficiency at angle of attack 12o.

Integrated Optimization Design for a Radial Turbine Wheel of a 100kW-Class Microturbine

2011 ◽  
Author(s):  
Lei Fu ◽  
Yan Shi ◽  
Qinghua Deng ◽  
Huaizhi Li ◽  
Zhenping Feng
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Aerodynamic Performance ◽  
Original Design ◽  
Element Analysis ◽  
Turbine Wheel ◽  
Strength Performance ◽  
Integrated Optimization ◽  
Radial Turbine ◽  
Integrated Optimization Design

The aerodynamic performance, structural strength and wheel weight are three important factors in the design process of the radial turbine. This paper presents an investigation on these aspects and develops an optimization design approach for radial turbine with consideration of the three factors. The aerodynamic design for the turbine wheel with inlet diameter of 230mm for 100kW-class microturbine unit is carried out firstly as the original design. Then, the cylinder parabolic geometrical design method is applied to the wheel modeling and structural design, but the maximum stress predicted by Finite Element Analysis greatly exceeds the yield limit of material. Furthermore, the wheel weight is above 7.2kg thus bringing some critical difficulties for bearing design and turbine operation. Therefore, an integrated optimization design method for radial turbine is studied and developed in this paper with focus on the wheel design. Meridional profiles and shape lines of turbine wheel are optimized with consideration of the whole wheel weight. Main structural modeling parameters are reselected to reduce the wheel weight. Trade-off between aerodynamic performance and strength performance is highly emphasized during the optimization design. The results show that the optimized turbine wheel gets high aerodynamic performance and acceptable stress distribution with the weight less than 3.8kg.

scholarly journals Design of an Incompressible High-Pressure Vaneaxial Fan Using CFD

1992 ◽  
Author(s):  
Y. T. Lee ◽  
J. Feng ◽  
M. E. Slipper ◽  
C. L. Merkle
Keyword(s):  
Fluid Dynamics ◽  
High Pressure ◽  
Design Method ◽  
Aerodynamic Performance ◽  
Code Verification ◽  
Cfd Modelling ◽  
Geometrical Characteristics ◽  
Coupling Procedure ◽  
Rotor Stator Interaction ◽  
Computational Fluid Dynamics Cfd

An advanced computational fluid dynamics (CFD) modelling design method using a numerical viscous/inviscid coupling procedure has been developed. The method is employed to analytically evaluate the performance of various combinations of high pressure vaneaxial fan rotor, stator and diffuser geometries. The procedures used in the CFD design method ensure a free-vortex blading, a separation-free profile, and a configuration with optimum rotor-stator interaction. Two test fans which have aerodynamic performance and geometrical characteristics close to the desired fan operating range are used to provide code verification and empirical information for the total design effort. A design example is presented. Aerodynamic and aeroacoustic test data will be presented in a later paper.

scholarly journals Effect of Wing Corrugation on the Aerodynamic Efficiency of Two-Dimensional Flapping Wings

2020 ◽  
Vol 10 (20) ◽  
pp. 7375
Author(s):  
Thanh Tien Dao ◽  
Thi Kim Loan Au ◽  
Soo Hyung Park ◽  
Hoon Cheol Park
Keyword(s):  
Three Dimensional ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Flapping Wing ◽  
Flapping Wings ◽  
Two Dimensional ◽  
Aerodynamic Efficiency ◽  
Insect Wing ◽  
Wing Motion ◽  
Computational Fluid Dynamics Cfd

Many previous studies have shown that wing corrugation of an insect wing is only structurally beneficial in enhancing the wing’s bending stiffness and does not much help to improve the aerodynamic performance of flapping wings. This study uses two-dimensional computational fluid dynamics (CFD) in aiming to identify a proper wing corrugation that can enhance the aerodynamic performance of the KUBeetle, an insect-like flapping-wing micro air vehicle (MAV), which operates at a Reynolds number of less than 13,000. For this purpose, various two-dimensional corrugated wings were numerically investigated. The two-dimensional flapping wing motion was extracted from the measured three-dimensional wing kinematics of the KUBeetle at spanwise locations of r = (0.375 and 0.75)R. The CFD analysis showed that at both spanwise locations, the corrugations placed over the entire wing were not beneficial for improving aerodynamic efficiency. However, for the two-dimensional flapping wing at the spanwise location of r = 0.375R, where the wing experiences relatively high angles of attack, three specially designed wings with leading-edge corrugation showed higher aerodynamic performance than that of the non-corrugated smooth wing. The improvement is closely related to the flow patterns formed around the wings. Therefore, the proposed leading-edge corrugation is suggested for the inboard wing of the KUBeetle to enhance aerodynamic performance. The corrugation in the inboard wing may also be structurally beneficial.

scholarly journals Simulating bio-composite cycling helmet performance through FEA and CFD approaches

2015 ◽  
Vol 4 ◽  
Author(s):  
Mohd Naim Abdullah
Keyword(s):  
Aerodynamic Performance ◽  
Cfd Analysis ◽  
Critical Area ◽  
Element Analysis ◽  
Critical Areas ◽  
Air Resistance ◽  
Oblique Loading ◽  
Design For Safety ◽  
Computational Fluid Dynamics Cfd ◽  
Fea Analysis

<p>Finite Element Analysis (FEA) and Computational Fluid Dynamics (CFD) analysis were performed in this work in order to obtain the best design for safety and aerodynamic performance of the bicycle cycling helmet. FEA analysis was computed on two different helmet designs to determine the critical area subjected to impact. A pressure load was applied on the helmets’ outer surface to simulate oblique loading. The critical areas of the helmets were then highlighted and identified, enabling design improvements to be made on both designs. CFD analysis was then executed in order to obtain the lowest drag coefficient number in reducing the air resistance induced by both of the helmet designs, inherently increasing cyclist performance and ensuring competition success.</p>

Integrated Optimization Design for a Radial Turbine Wheel of a 100 kW-Class Microturbine

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Lei Fu ◽  
Yan Shi ◽  
Qinghua Deng ◽  
Huaizhi Li ◽  
Zhenping Feng
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Aerodynamic Performance ◽  
Original Design ◽  
Element Analysis ◽  
Turbine Wheel ◽  
Strength Performance ◽  
Integrated Optimization ◽  
Radial Turbine ◽  
Integrated Optimization Design

The aerodynamic performance, structural strength, and wheel weight are three important factors in the design process of the radial turbine. This paper presents an investigation on these aspects and develops an optimization design approach for radial turbine with consideration of the three factors. The aerodynamic design for the turbine wheel with an inlet diameter of 230 mm for the 100 kW-class microturbine unit is carried out first as the original design. Then, the cylinder parabolic geometrical design method is applied to the wheel modeling and structural design, but the maximum stress predicted by finite element analysis greatly exceeds the yield limit of material. Further, the wheel weight is above 7.2 kg, thus, bringing some critical difficulties for bearing design and turbine operation. Therefore, an integrated optimization design method for radial turbine is studied and developed in this paper with focus on the wheel design. Meridional profiles and shape lines of the turbine wheel are optimized with consideration of the whole wheel weight. Main structural modeling parameters are reselected to reduce the wheel weight. Trade-off between aerodynamic performance and strength performance is highly emphasized during the optimization design. The results show that the optimized turbine wheel gets high aerodynamic performance and acceptable stress distribution with a weight less than 3.8 kg.

scholarly journals Insights into Sensitivity of Wing Shape and Kinematic Parameters Relative to Aerodynamic Performance of Flapping Wing Nano Air Vehicles

Drones ◽  
2019 ◽  
Vol 3 (2) ◽  
pp. 49 ◽  
Author(s):  
G. Throneberry ◽  
M. Hassanalian ◽  
A. Abdelkefi
Keyword(s):  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Flapping Wing ◽  
Wing Shape ◽  
Physical Factors ◽  
Kinematic Parameters ◽  
Aerodynamic Forces ◽  
Hovering Flight ◽  
Time Histories ◽  
Air Vehicles

In this work, seven wings inspired from insects’ wings, including those inspired by the bumblebee, cicada, cranefly, fruitfly, hawkmoth, honeybee, and twisted parasite, are patterned and analyzed in FlapSim software in forward and hovering flight modes for two scenarios, namely, similar wingspan (20 cm) and wing surface (0.005 m2). Considering their similar kinematics, the time histories of the aerodynamic forces of lift, thrust, and required mechanical power of the inspired wings are calculated, shown, and compared for both scenarios. The results obtained from FlapSim show that wing shape strongly impacts the performance and aerodynamic characteristics of the chosen seven wings. To study the effects of different geometrical and physical factors including flapping frequency, elevation amplitude, pronation amplitude, stroke-plane angle, flight speed, wing material, and wingspan, several analyses are carried out on the honeybee-inspired shape, which had a 20 cm wingspan. This study can be used to evaluate the efficiency of different bio-inspired wing shapes and may provide a guideline for comparing the performance of flapping wing nano air vehicles with forward flight and hovering capabilities.

scholarly journals Computational fluid dynamics (CFD) simulation analysis on retinal gas cover rates using computational eye models

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Makoto Gozawa ◽  
Yoshihiro Takamura ◽  
Tomoe Aoki ◽  
Kentaro Iwasaki ◽  
Masaru Inatani
Keyword(s):  
Cfd Simulation ◽  
Simulation Analysis ◽  
Fluid Dynamic ◽  
Fluid Analysis ◽  
Intraocular Gas ◽  
Pars Plana ◽  
Computational Fluid Dynamics Cfd ◽  
Multiple Breaks ◽  
Gas Volume ◽  
Wall Wettability

AbstractWe investigated the change in the retinal gas cover rates due to intraocular gas volume and positions using computational eye models and demonstrated the appropriate position after pars plana vitrectomy (PPV) with gas tamponade for rhegmatogenous retinal detachments (RRDs). Computational fluid dynamic (CFD) software was used to calculate the retinal wall wettability of a computational pseudophakic eye models using fluid analysis. The model utilized different gas volumes from 10 to 90%, in increments of 10% to the vitreous cavity in the supine, sitting, lateral, prone with closed eyes, and prone positions. Then, the gas cover rates of the retina were measured in each quadrant. When breaks are limited to the inferior retina anterior to the equator or multiple breaks are observed in two or more quadrants anterior to the equator, supine position maintained 100% gas cover rates in all breaks for the longest duration compared with other positions. When breaks are limited to either superior, nasal, or temporal retina, sitting, lower temporal, and lower nasal position were maintained at 100% gas cover rates for the longest duration, respectively. Our results may contribute to better surgical outcomes of RRDs and a reduction in the duration of the postoperative prone position.

scholarly journals Electromagnetic-Thermal Integration Design of Permanent Magnet Motor for Vehicles

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Shijun Chen ◽  
Qi Zhang ◽  
Surong Huang
Keyword(s):  
Permanent Magnet ◽  
High Performance ◽  
Design Method ◽  
Electromagnetic Properties ◽  
Permanent Magnet Motor ◽  
Element Analysis ◽  
Experiment Platform ◽  
Motor Design ◽  
Dimensional Parameters ◽  
Thermal Integration

To more efficiently design high performance vehicular permanent magnet motor, an electromagnetic-thermal integration design method is presented, which considers both the electromagnetic properties and the temperature rise of motor winding when determining the main dimensional parameters of the motor. Then a 48-slot and 8-pole vehicular permanent magnet motor is designed with this method. The thermomagnetic coupling design is simulated and validated on the basis of multiphysical domain on finite element analysis. Then the prototype is analyzed and tested on a newly built motor experiment platform. It is shown that the simulation results and experimental results are consistent, which validate the accuracy and effectiveness of the new design method. Also this method is proved to well improve the efficiency of permanent magnet motor design.

scholarly journals Numerical Investigation for the Resin Filling Behavior during Ultraviolet Nanoimprint Lithography of Subwavelength Moth-Eye Nanostructure

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 799
Author(s):  
Yuanchi Cui ◽  
Xuewen Wang ◽  
Chengpeng Zhang ◽  
Jilai Wang ◽  
Zhenyu Shi
Keyword(s):  
Simulation Model ◽  
Nanoimprint Lithography ◽  
Cfd Simulation ◽  
Boundary Slip ◽  
Accurate Analysis ◽  
Inlet Velocity ◽  
Filling Height ◽  
Proposed Model ◽  
Good Consistency ◽  
Computational Fluid Dynamics Cfd

Accurate analysis of the resin filling process into the mold cavity is necessary for the high-precision fabrication of moth-eye nanostructure using the ultraviolet nanoimprint lithography (UV-NIL) technique. In this research, a computational fluid dynamics (CFD) simulation model was proposed to reveal resin filling behavior, in which the effect of boundary slip was considered. By comparison with the experimental results, a good consistency was found, indicating that the simulation model could be used to analyze the resin filling behavior. Based on the proposed model, the effects of process parameters on resin filling behavior were analyzed, including resin viscosity, inlet velocity and resin thickness. It was found that the inlet velocity showed a more significant effect on filling height than the resin viscosity and thickness. Besides, the effects of boundary conditions on resin filling behavior were investigated, and it was found the boundary slip had a significant influence on resin filling behavior, and excellent filling results were obtained with a larger slip velocity on the mold side. This research could provide guidance for a more comprehensive understanding of the resin filling behavior during UV-NIL of subwavelength moth-eye nanostructure.

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