Influence of the uniform flow on flow characteristics of tandem flapping wings

2018 ◽  
Vol 2018.55 (0) ◽  
pp. F022
Author(s):  
Hirofumi TSUCHIDA ◽  
Wataru YAMAZAKI
Keyword(s):  
Flow Characteristics ◽  
Uniform Flow ◽  
Flapping Wings ◽  
Tandem Flapping Wings

Ground effect on tandem flapping wings hovering

2017 ◽  
Vol 152 ◽  
pp. 40-56 ◽  
Author(s):  
N.G. Srinidhi ◽  
S. Vengadesan
Keyword(s):  
Ground Effect ◽  
Flapping Wings ◽  
Tandem Flapping Wings

Flow Characteristics of a Bluff Body Cut From a Circular Cylinder

1997 ◽  
Vol 119 (2) ◽  
pp. 453-454 ◽  
Author(s):  
S. Aiba ◽  
H. Watanabe
Keyword(s):  
Circular Cylinder ◽  
Drag Coefficient ◽  
Flow Velocity ◽  
Bluff Body ◽  
Pressure Coefficient ◽  
Angular Position ◽  
Flow Characteristics ◽  
Uniform Flow ◽  
Base Pressure ◽  
Singular Flow

This is a report on an investigation of the flow characteristics of a bluff body cut from a circular cylinder. The volume removed from the cylinder is equal to d/2(1 − cos θs), where d and θs are the diameter and the angular position (in the case of a circular cylinder, θs, = 0 deg), respectively. θs, ranged from 0 deg to 72.5 deg and Re (based on d and the upstream uniform flow velocity U∞) from 2.0 × 104 to 3.5 × 104. It is found that a singular flow around the cylinder occurs at around θs = 53 deg when Re > 2.5 × 104, and the base pressure coefficient (−Cpb,) and the drag coefficient CD take small values compared with those for otherθs.

scholarly journals Collective Flow Enhancement by Tandem Flapping Wings

2015 ◽  
Vol 115 (18) ◽  
Author(s):  
Nick Gravish ◽  
Jacob M. Peters ◽  
Stacey A. Combes ◽  
Robert J. Wood
Keyword(s):  
Flapping Wings ◽  
Collective Flow ◽  
Flow Enhancement ◽  
Tandem Flapping Wings

A Computational Study on the Effect of Angles of Attack on a Double-Cone Type Supersonic Inlet With Bleeding System

2010 ◽  
Author(s):  
Kyung Jin Ryu ◽  
Seol Lim ◽  
Sang Dug Kim ◽  
Dong Joo Song
Keyword(s):  
Boundary Layer ◽  
Flow Field ◽  
Computational Study ◽  
Angle Of Attack ◽  
Flow Characteristics ◽  
Uniform Flow ◽  
Double Cone ◽  
Interface Plane ◽  
Supersonic Inlet ◽  
Cone Type

The flow characteristics on a supersonic inlet with bleeding system at various angles of attack are studied by using computational 3D turbulent flow analysis. A turbulent CSCM compressible upwind flux difference splitting Navier-Stokes method with k-w turbulence model is used to compute the inlet flowfields. MPICH-2.0 library and PC-cluster system are used to reduce computational times. Distortion and average of total pressure recovery at the AIP (aerodynamic interface plane) are used as evaluation criteria of inlet performance. The flow characteristics at zero of angle of attack of double-cone type supersonic inlet without and with bleeding system have been compared. Without bleeding system inlet with the strong SBLI (shock/boundary-layer interaction) induces slow flow recovery near the throat and produces very thick boundary layer downstream. But the bleeding system successfully removes the low energy flow from the boundary layer near the throat. As the angle of attack at the AIP because large, we can see more non-uniform flow field, and the non-uniform flow field is the major aggravating factor of inlet performance.

On the Propulsive Performance of Tandem Flapping Wings with a Modified Immersed Boundary Method

2016 ◽  
Vol 13 (05) ◽  
pp. 1650025 ◽  
Author(s):  
Dingyi Pan ◽  
Jian Deng ◽  
Xueming Shao ◽  
Zubin Liu
Keyword(s):  
Immersed Boundary Method ◽  
Thrust Force ◽  
Wake Flow ◽  
Flapping Wings ◽  
Immersed Boundary ◽  
Phase Lag ◽  
Boundary Method ◽  
Total Thrust ◽  
Tandem Flapping Wings ◽  
The One

The modified immersed boundary method is introduced and applied to study the propulsive mechanism of a tandem flapping wings system. The effects of tandem wings distance and phase lag between the two flapping wings are investigated. Thrust force of the upstream wing is nearly constant and close to the magnitude of single flapping wing system. Thrust force of second wing is influenced by the distance and phase lag. With specific parameters, the second wing can obtain a maximum thrust which is larger than the one of first wing. The flow structures of the wake flow are classified into three different formations, and they are correlated to the trends of thrust force. The effects of distance and phase lag are coupled other than isolated. It is possible to lower down the power consumption of this tandem flapping wings system and enhance the total thrust force of the system at the same time.

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