scholarly journals Fluid Dynamic Forces on Plunging Spanwise-Flexible Elliptical Flat Plates at Low Reynolds Numbers

2011 ◽  
Author(s):  
Jonathan Rausch ◽  
Luis Bernal ◽  
Carlos Cesnik ◽  
Wei Shyy ◽  
Lawrence Ukeiley
Keyword(s):  
Fluid Dynamic ◽  
Reynolds Numbers ◽  
Flat Plates ◽  
Low Reynolds Numbers ◽  
Dynamic Forces ◽  
Low Reynolds

scholarly journals Force and flowfield measurements to understand unsteady aerodynamics of cycloidal rotors in hover at ultra-low Reynolds numbers

2019 ◽  
Vol 11 ◽  
pp. 175682931983367
Author(s):  
Carolyn M Reed ◽  
David A Coleman ◽  
Moble Benedict
Keyword(s):  
Separation Bubble ◽  
Fluid Dynamic ◽  
Unsteady Aerodynamics ◽  
Leading Edge ◽  
Reynolds Numbers ◽  
Dynamic Stall ◽  
Static Case ◽  
Low Reynolds Numbers ◽  
Curvature Effects ◽  
Low Reynolds

This paper provides a fundamental understanding of the unsteady fluid-dynamic phenomena on a cycloidal rotor blade operating at ultra-low Reynolds numbers (Re ∼ 18,000) by utilizing a combination of instantaneous blade force and flowfield measurements. The dynamic blade force coefficients were almost double the static ones, indicating the role of dynamic stall. For the dynamic case, the blade lift monotonically increased up to ±45° pitch amplitude; however, for the static case, the flow separated from the leading edge after around 15° with a large laminar separation bubble. There was significant asymmetry in the lift and drag coefficients between the upper and lower halves of the trajectory due to the flow curvature effects (virtual camber). The particle image velocimetry measured flowfield showed the dynamic stall process during the upper half to be significantly different from the lower half because of the reversal of dynamic virtual camber. Even at such low Reynolds numbers, the pressure forces, as opposed to viscous forces, were found to be dominant on the cyclorotor blade. The power required for rotation (rather than pitching power) dominated the total blade power.

scholarly journals Eddy Viscosities and Mixing Lengths for Turbulent Boundary Layers on Flat Plates, Smooth or Rough

1988 ◽  
Vol 32 (04) ◽  
pp. 229-237
Author(s):  
Paul S. Granville
Keyword(s):  
Boundary Layers ◽  
Rough Surfaces ◽  
Equations Of Motion ◽  
Reynolds Numbers ◽  
Turbulent Boundary Layers ◽  
Flat Plates ◽  
Low Reynolds Numbers ◽  
Low Reynolds ◽  
Similarity Laws

Algebraic formulas are derived here for the eddy viscosities and mixing lengths of turbulent boundary layers on flat plates. The effect of low Reynolds numbers, especially on rough surfaces, is included. The formulas are based on the similarity laws and the equations of motion. Both smooth and rough surfaces are considered. The agreement with Klebanoff's measurements is excellent.

The drag on oscillating flat plates in liquids at low Reynolds numbers

1971 ◽  
Vol 48 (2) ◽  
pp. 229-239 ◽  
Author(s):  
Cornelius C. Shih ◽  
Harry J. Buchanan
Keyword(s):  
Reynolds Number ◽  
Drag Coefficient ◽  
Reynolds Numbers ◽  
Motor Oil ◽  
Flat Plates ◽  
Low Reynolds Numbers ◽  
Two Fluids ◽  
Low Reynolds ◽  
The Relationship ◽  
Graphical Presentation

An experimental investigation was conducted to describe the fluid flow about oscillating flat plates and to determine the magnitude and nature of forces acting on the plates at low Reynolds numbers. In the experiment, the Reynolds number was varied from 1·01 to 1057·0; three period parameters, 1·57, 2·07 and 4·71, were applied; two fluids, water and SAE 30 motor oil, and three flat plates of various sizes with or without end plates were used. The analysis of data resulted in graphical presentation of the relationships among the drag coefficient, the Reynolds number and period parameter. The drag coefficient becomes less dependent on the Reynolds number for values greater than 250. The relationship between the drag coefficient and period parameter is pronounced throughout the entire range of the Reynolds number tested.

scholarly journals Fluid Dynamics of Rigid and Spanwise-Flexible Elliptical Flat Plates at Low Reynolds Numbers

2010 ◽  
Author(s):  
Jonathan Rausch ◽  
Yeon Baik ◽  
Luis Bernal ◽  
Wei Shyy ◽  
Michael Ol ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Reynolds Numbers ◽  
Flat Plates ◽  
Low Reynolds Numbers ◽  
Low Reynolds

Unsteady Aerodynamic Characteristics of Pitching Flat Plates at Low Reynolds Numbers

2021 ◽  
pp. 1-18
Author(s):  
Camli Badrya ◽  
Bharath Govindarajan ◽  
Albert Medina ◽  
Seung Joon Yang ◽  
Inderjit Chopra
Keyword(s):  
Reynolds Numbers ◽  
Aerodynamic Characteristics ◽  
Flat Plates ◽  
Low Reynolds Numbers ◽  
Unsteady Aerodynamic ◽  
Low Reynolds

High-Resolution Numerical Simulation of Low Reynolds Number Incompressible Flow About Two Cylinders in Tandem

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Sintu Singha ◽  
K. P. Sinhamahapatra
Keyword(s):  
Reynolds Number ◽  
Incompressible Flows ◽  
Fluid Dynamic ◽  
Low Reynolds Number ◽  
Reynolds Numbers ◽  
Circular Cylinders ◽  
Dynamic Forces ◽  
Low Reynolds ◽  
Volume Method ◽  
Global Parameters

Low Reynolds number steady and unsteady incompressible flows over two circular cylinders in tandem are numerically simulated for a range of Reynolds numbers with varying gap size. The governing equations are solved on an unstructured collocated mesh using a second-order implicit finite volume method. The effects of the gap and Reynolds number on the vortex structure of the wake and on the fluid dynamic forces acting on the cylinders are reported and discussed. Both the parameters have significant influence on the flow field. An attempt is made to unify their influence on some global parameters.

Sign in / Sign up

Export Citation Format

Share Document