Lift of a bio-inspired flapping wing with a dynamic trailing-edge flap in forward flight

doi:10.1063/5.0146636

Physics of Fluids

2023

DOI: 10.1063/5.0146636

|View full text |Cite

Lift of a bio-inspired flapping wing with a dynamic trailing-edge flap in forward flight

Abstract: Unlike the tail of a bird, regarded as a separately controlled aerodynamic surface, the membrane tail of a bat is operated as a dynamic trailing-edge flap. We investigate the effects of a dynamic trailing-edge flap on unsteady lift by numerically solving the Navier–Stokes equations around a bio-inspired flapping wing. The peak of the lift coefficient in the downstroke is considerably affected by the phase difference between the dynamic trailing-edge flap and the elevation. A quasi-steady formula is proposed to… Show more

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...

Citation Types

Supporting

Mentioning

Contrasting

Year Published

2023

2024

Publication Types

Select...

Article3

Relationship

Self Cite0

Independent3

Authors

Journals

Cited by 3 publications

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

Wavelet analysis of the flow field around an oscillating airfoil undergoing pure pitching motion at low Reynolds number

2023

View full text Add to dashboard Cite

This paper investigates the flow field around a NACA (National Advisory Committee for Aeronautics) 0012 airfoil undergoing pure pitching motion using continuous wavelet transform. Wind tunnel experiments were performed with a test-stand that provides a wide range of oscillation frequencies (f = 0–10 Hz). Sinusoidal pure pitching motion was considered with respect to the quarter chord for five reduced frequencies (K = 0.05, 0.1, 0.15, 0.2, and 0.3) at a Reynolds number of Re = 6 × 104. Mean angle of attack and pitch amplitude for all the cases were considered 0° and 6°, respectively. Unsteady surface pressure measurement was conducted, and the lift coefficient was calculated based on the phase-averaged surface pressure coefficient. The unsteady velocity distributions in the airfoil wake have been measured employing a pressure rake. The results indicate that the maximum value of the lift coefficient decreases by increasing the reduced frequency due to the “apparent mass” effects. For K = 0.05, close to the quasi-steady regime, the cl-α loop approximately follows the trend of the static case. Wavelet transform was used as a tool to examine the surface and wake pressure time series. Surface pressure wavelet transform plots indicate the presence of oscillation frequency and its superharmonics. Moreover, surface pressure wavelet analysis shows that the third and higher superharmonic frequencies are sensitive to the airfoil pitch angle during the oscillation cycle. Wavelet transform on wake reveals that the effective wake width gets smaller by increasing the reduced frequency. Furthermore, the trailing edge vortices get weaker by increasing the reduced frequency.

show abstract

Wavelet analysis of the flow field around an oscillating airfoil undergoing pure pitching motion at low Reynolds number

2023

View full text Add to dashboard Cite

show abstract

Numerical and experimental studies of a morphing airfoil with trailing edge high-frequency flapping

Zhang,

Chen,

Xia

et al. 2023

Physics of Fluids

View full text Add to dashboard Cite

The aerodynamic performance of a morphing airfoil is numerically and experimentally investigated. The morphing airfoil is designed based on macro fiber composites, capable of trailing edge flapping during 10–90 Hz with a maximum amplitude of 0.55 mm. A numerical model with flexible deformation walls based on the experiment is established to precisely restore the actual dynamic morphing instead of segmental deformation to explore the transient aerodynamic performance of high-frequency flapping. The drag coefficient is reduced by 2.07% at the flapping frequency (ff) of 37.5 Hz compared with the rigid airfoil, while the drag coefficient and the lift coefficient increase by 4.8% and 5.8% for ff at 600 Hz. The vortex is broken up by flapping, and the corresponding position has been forwarded to the tail. Dynamic mode decomposition shows that the wing's flapping dominates the second mode and the high-frequency vortex has changed to low-frequency. The energy of higher modes is transferred to lower-order modes that the first mode's power has risen sharply from 49.29% of the rigid airfoil to 91.83%. In the wind tunnel experiment, the lift and drag forces are increased by 1.88% and 0.77% at the flapping frequency of 40 Hz, respectively. Furthermore, the lift force frequency is locked by flapping and changes from 124.9 Hz of the rigid airfoil to the flapping frequency, consistent with the computational fluid dynamics results. The research has provided a solution to reduce the drag force and increase the lift force of the aircraft by the trailing edge flapping.

show abstract

Wing design optimization and stall analysis with Co-flow Jet active control

Jiang,

Yao,

Zheng

et al. 2024

Physics of Fluids

View full text Add to dashboard Cite

Coupled with Co-flow Jet (CFJ) technology, the Non-dominated Sorting Genetic Algorithm II was utilized for the multi-objective combination optimization of an optimized Co-flow Jet wing, based on National Advisory Committee for Aeronautics (NACA) 6421. A high-precision numerical simulation using the delayed detached eddy simulation model was performed on the optimized wing to investigate the three-dimensional flow separation characteristics after static stall. The stall improvement was investigated by adjusting the momentum coefficient of the injection. The results show that the optimized wing exhibits significant improvements in aerodynamic performance and corrected aerodynamic efficiency. At an angle of attack of 10°, the average lift increased by 16.25% and the drag decreased by 27.23% compared to the CFJ6421 wing, while effectively addressing the problem of low modified aerodynamic efficiency of the CFJ wing at lower angles of attack. By utilizing higher momentum and improving the boundary layer control capability, flow separation is effectively suppressed, thus achieving the goal of stall recovery of the CFJ wing.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

hi@scite.ai

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Lift of a bio-inspired flapping wing with a dynamic trailing-edge flap in forward flight

Cited by 3 publications

References 25 publications

Wavelet analysis of the flow field around an oscillating airfoil undergoing pure pitching motion at low Reynolds number

Wavelet analysis of the flow field around an oscillating airfoil undergoing pure pitching motion at low Reynolds number

Numerical and experimental studies of a morphing airfoil with trailing edge high-frequency flapping

Wing design optimization and stall analysis with Co-flow Jet active control

Contact Info

Product

Resources

About