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.

Vortex shedding from bluff bodies in a shear flow

1973 ◽  
Vol 60 (2) ◽  
pp. 401-409 ◽  
Author(s):  
D. J. Maull ◽  
R. A. Young
Keyword(s):  
Shear Flow ◽  
Vortex Shedding ◽  
Bluff Body ◽  
Pressure Coefficient ◽  
Uniform Flow ◽  
Base Pressure ◽  
Longitudinal Vortex ◽  
Bluff Bodies ◽  
Stream Direction

Experiments are described in which the vortex shedding from a bluff body and the base pressure coefficient have been measured in a shear flow. It is shown that the shedding breaks down into a number of spanwise cells in each of which the frequency is constant. The division between the cells is thought to be marked by a longitudinal vortex in the stream direction and this is supported by evidence from experiments where a longitudinal vortex was generated in an otherwise uniform flow.

An Investigation of the Flow around Rectangular Cylinders

1972 ◽  
Vol 23 (3) ◽  
pp. 229-237 ◽  
Author(s):  
P W Bearman ◽  
D M Trueman
Keyword(s):  
Drag Coefficient ◽  
Strouhal Number ◽  
Pressure Coefficient ◽  
Base Pressure ◽  
Trailing Edge ◽  
Rectangular Cylinders

SummaryMeasurements are presented of the base pressure coefficient, drag coefficient and Strouhal number of rectangular cylinders. The results confirm a finding in Japan that the drag coefficient rises to nearly 3 when the depth of the section is just over half the width. The flow around the sections is found to be strongly influenced by the presence of the trailing-edge corners.

Experimental Studies on Loads Acting on Two Piles of Side-by-Side Arrangements in the Uniform Flow

2012 ◽  
Vol 226-228 ◽  
pp. 1785-1788
Author(s):  
Zhao Qing Zhu ◽  
Guo Liang Dai
Keyword(s):  
Drag Coefficient ◽  
Flow Velocity ◽  
Experimental Studies ◽  
Reynolds Numbers ◽  
Uniform Flow ◽  
Drag Forces ◽  
Pile Diameter ◽  
Two Component ◽  
Balance Analysis ◽  
Different Diameters

Indoor model experiments were made to study drag loads on two piles of side-by-side arrangements in the uniform flow. Take three different velocities of the flow, three different diameters of piles and five different distances of two piles in the experiments to get the variations of loads. Drag forces were measured by a two-component balance. Analysis on experiment results shows that drag forces increase with the increase of the pile diameter, the increase of the flow velocity and the decrease of the distance of two piles. The drag coefficient CDunder different Reynolds numbers shows the same change law. The drag coefficient CDdecreases with the increase of the distance of two piles and has good coherence to the ratio of the distance of two piles to the pile diameter.

The Influence of Vortex Generators on the Drag and Heat Transfer From a Circular Cylinder Normal to an Airstream

1969 ◽  
Vol 91 (1) ◽  
pp. 91-99 ◽  
Author(s):  
T. R. Johnson ◽  
P. N. Joubert
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Circular Cylinder ◽  
Drag Coefficient ◽  
Angular Position ◽  
Vortex Generator ◽  
Vortex Generators ◽  
Experimental Investigations ◽  
Stagnation Line

Experimental investigations were carried out to examine the effect of vortex generators on drag and heat transfer from a circular cylinder in a crossflow. The cylinder was fitted with two rows of vortex generators which were symmetrically placed on either side of and parallel to the front stagnation line. One configuration of vortex generator was used and the angular position of the rows from the front stagnation line was varied. In the heat transfer runs the vortex generator position remained unvaried. Results are presented to show the variation of drag coefficient with Reynolds number for several angular positions of the generator rows. Results are also presented to show the variation of Nusselt number with Reynolds number both for a cylinder with and without generators. These show that both decreases in drag coefficient and increases in Nusselt number can be obtained when vortex generators are fitted.

Reduction of Drag Force on a Circular Cylinder and Pressure Drop Using a Square Cylinder as Disturbance Body in a Narrow Channel

2014 ◽  
Vol 493 ◽  
pp. 192-197 ◽  
Author(s):  
Wawan Aries Widodo ◽  
Randi Purnama Putra
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Wind Tunnel ◽  
Circular Cylinder ◽  
Drag Force ◽  
Bluff Body ◽  
Flow Characteristics ◽  
Narrow Channel ◽  
Square Cylinder ◽  
Cross Sectional

Many studies related with characteristics of fluid flow acrossing in a bluff body have been conducted. The aim of this research paper was to reduce pressure drop occuring in narrow channels, in which there was a circular cylindrical configuration with square cylinder as disturbance body. Another goal of this research was to reduce the drag force occuring in circular cylinder. Experimentally research of flow characteristics of the wind tunnel had a narrow channel a square cross-section, with implemenred of Reynolds number based on the hydraulic diameter from 5.21x104 to 1.56x105. Wind tunnel that was used had a 125x125mm cross-sectional area and the blockage ratio 26.4% and 36.4%. Specimen was in the form of circular cylinder and square cylinder as disturbance body. Variation of angle position was the inlet disturbance body with α = 200, 300, 400, 500 and 600, respectively. The results was obtained from this study was Reynolds Number value was directly linear with pressure drop there, it was marked by increasing of Reynolds number, the value was also increasing pressure drop. Additional information was obtained by adding inlet disturbance body shaped of square cylinder on the upstream side of the circular cylinder that could reduce pressure drop in the duct and reduce drag happening on a circular cylinder. The position of the optimum angle to reduce pressure drop and drag force was found on the inlet disturbance body with angle α = 300.

scholarly journals Flow of a Fluid with Pressure-Dependent Viscosity through Variable Permeability Porous Layer

2021 ◽  
Vol 16 ◽  
pp. 204-212
Author(s):  
M. S. Abu Zaytoon ◽  
Yiyun (Lisa) Xiao ◽  
M. H. Hamdan
Keyword(s):  
Drag Coefficient ◽  
Flow Velocity ◽  
Control Parameter ◽  
Flow Model ◽  
Flow Characteristics ◽  
Permeability Model ◽  
Proportionality Constant ◽  
Variable Permeability ◽  
Pressure Dependent Viscosity ◽  
Dependent Viscosity

In this work, we consider flow of a fluid with pressure-dependent viscosity down an inclined porous plane with variable permeability that is incorporated in the pressure-dependent drag coefficient. We provide a solution to a recently developed flow model, and study the effects of flow and domain parameters (viscosity control parameter, permeability proportionality constant, and angle of inclination) on the flow characteristics. Suitability of a variable permeability model that considers permeability proportional to the flow velocity is investigated. Results show that large values of the permeability proportionality constant have little or no effects on flow characteristics.

scholarly journals Research on Compressible Flow around Cylinder and Truncated Cone with LES Method

2014 ◽  
Vol 919-921 ◽  
pp. 210-215
Author(s):  
Meng Zhao ◽  
Jun Mao ◽  
Guo Wei Yang
Keyword(s):  
Drag Coefficient ◽  
Compressible Flow ◽  
Bluff Body ◽  
Lift Coefficient ◽  
Pressure Coefficient ◽  
Scale Model ◽  
Windward Side ◽  
Leeward Side ◽  
Filter Function ◽  
Truncated Cone

Numerical simulation with the large eddy simulation, filter function, and Smagorinsky sub-grid scale model is adopted to simulate the compressible flow around a bluff body finite length circular cylinder and truncated cone in high Reynolds number. The law of the drag coefficient, lift coefficient and pressure coefficient obtained from models with various cross-wind speeds was discussed. Process of the vortex generated, shed and dissipated was analyzed and the relationship between the press filed, velocity filed and vortex filed was also analyzed. Average value of the drag coefficient, lift coefficient and pressure coefficient of the circle cylinder in subcritical region are greater than truncated cone. Values of pressure coefficient on the windward side of all the models are consistent. However, it various widely on the leeward side, even on the end face of the cone and cylinder.

The Influence of Rotating Wheels on Vehicle Aerodynamics

2012 ◽  
Vol 246-247 ◽  
pp. 543-547 ◽  
Author(s):  
Ting Li ◽  
Qing Jia ◽  
Zhi Gang Yang
Keyword(s):  
Drag Coefficient ◽  
Lift Coefficient ◽  
Computational Simulation ◽  
Pressure Coefficient ◽  
Flow Characteristics ◽  
Aerodynamic Performance ◽  
Navier Stokes ◽  
Global Flow ◽  
Flow Surface ◽  
Vehicle Aerodynamics

Full scaled simplified model and production vehicle were applied to make a research on the local and global flow characteristics. Two different conditions including stationary and rotation were employed in computational simulation by steady RNS Navier-Stokes calculation. Further, detailed analysis on flow, surface pressure coefficient, drag coefficient and lift coefficient affected by rotating wheel figure out that rotating wheel has a significant influence on the flow around wheel and vehicle. Pressure difference, drag coefficient and lift coefficient are decreased by rotation, which improve aerodynamic performance.

Investigation of Wide Range of Flow around Circular Cylinder Using Turbulence Model

2013 ◽  
Vol 664 ◽  
pp. 878-883 ◽  
Author(s):  
Kee Quen Lee ◽  
Abu Aminudin ◽  
Muhamad Pauziah
Keyword(s):  
Experimental Data ◽  
Circular Cylinder ◽  
Drag Coefficient ◽  
Strouhal Number ◽  
Turbulence Model ◽  
Pressure Coefficient ◽  
Wide Range ◽  
Flow Around Circular Cylinder ◽  
Turbulence Length ◽  
Physical Features

The purpose of present study is to identify the possibility of predicting the physical features of circular cylinder in two dimensional for a wide range of Reynolds number using a modified turbulence model. The modification is focused on the turbulence length and intensity. The drag coefficient and the Strouhal number were calculated and compared with the existing experimental data. The contour of vorticity and pressure gradient were also presented. Although variation up to 159% was noted in the drag coefficient, it was just on a particular Reynolds number.The simulated outputs of Strouhal number, pressure coefficient and vorticity contour indicated reasonable agreement with the experimental data. The modified turbulence model has showed potential in simulating the flow around the circular cylinder.

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