**Commenced**in January 2007

**Frequency:**Monthly

**Edition:**International

**Paper Count:**184

# Search results for: Cylinder

##### 184 Numerical Analysis of Flow past Circular Cylinder with Triangular and Rectangular Wake Splitter

**Authors:**
Pavan Badami,
Vivek Shrivastava,
Saravanan V.,
Nandeesh Hiremath,
K. N. Seetharamu

**Abstract:**

**Keywords:**
Coefficient of drag and pressure,
CFDFLUENT,
Triangular and rectangular wake splitter,
wake length.

##### 183 Statistical Description in the Turbulent Near Wake of a Rotating Circular Cylinder

**Authors:**
Sharul S. Dol,
U. Azimov,
Robert J. Martinuzzi

**Abstract:**

**Keywords:**
Rotating circular cylinder,
Reynolds stress,
vortex.

##### 182 On the Numerical Simulation of Flow Past an Oscillating Circular Cylinder in a Circular Path: Oscillation Amplitude Effect

**Authors:**
Qasem M. Al-Mdallal

**Abstract:**

**Keywords:**
Lock-on; streamwise oscillation; transverse
oscillation; fluid forces,
combined motion

##### 181 Multiscale Structures and Their Evolution in a Screen Cylinder Wake

**Authors:**
Azlin M. Azmi,
T. Zhou,
A. Rinoshika,
L. Cheng

**Abstract:**

The turbulent structures in the wake (*x/d *=10 to 60) of a screen cylinder have been educed to understand the roles of the various structures as evolving downstream by comparing with those obtained in a solid circular cylinder wake at Reynolds number, *Re *of 7000. Using a wavelet multiresolution technique, the flow structures are decomposed into a number of wavelet components based on their central frequencies. It is observed that in the solid cylinder wake, large-scale structures (of frequency*f _{0}* and 1.2

*f*) make the largest contribution to the Reynolds stresses although they start to lose their roles significantly at

_{0}*x/d*> 20. In the screen cylinder wake, the intermediate-scale structures (2

*f*and 4

_{0 }*f*) contribute the most to the Reynolds stresses at

_{0}*x/d*=10 before being taken over by the large-scale structures (

*f*) further downstream.

_{0}**Keywords:**
Turbulent structure,
screen cylinder,
vortex,
wavelet multiresolution analysis.

##### 180 Dynamics of a Vapour Bubble inside a Vertical Rigid Cylinder with a Deposit Rib

**Authors:**
S. Mehran,
S. Rouhi,
F.Rouzbahani,
E. Haghgoo

**Abstract:**

**Keywords:**
Vapour bubble,
Vertical rigid cylinder,
Boundaryelement method.

##### 179 Contribution to Active and Passive Control of Flow around a Cylinder

**Authors:**
M. Tahar Bouzaher

**Abstract:**

This numerical study aims to develop a coupled, passive and active control strategy of the flow around a cylinder of diameter D, and Re=4000. The strategy consists to put a cylindrical rod in front of a deforming cylinder. The quasi- elliptical deformation of cylinder follow a sinusoidal law in order to reduce the drag force. To analyze the evolution of unsteady vortices, the Large Eddy Simulation approach is used in this 2D simulation, carried out using ANSYS – Fluent. The movement of deformation is reproduced using an internal subroutine, introduced in the form of a User Defined Function UDF. Two diameters of the rod were tested for a rod placed at a distance L = 3 ×d, with an amplitudes of deformation A = 5%, A = 25% and A = 50% of the cylinder diameter, the frequency of deformation take the values fd = 1fn, 5fn and 8fn, which fn represents the naturel vortex shedding frequency. The results show substantial changes in the flow behavior and for a rod of 6mm (1% D) with amplitude A = 25%, and with a 2fn frequency, drag reduction of 60% was recorded.

**Keywords:**
CFD,
Flow separation,
control,
Boundary layer,
rod,
Cylinder.

##### 178 Application of Metakaolin from Northeast of Thailand Used as Binder in Casting Process of Rice Polishing Cylinder

**Authors:**
T. Boonkang,
C. Santhaweesuk,
N. Pianthong,
P. Neeramon,
A. Phimhlo,
S. Bangphan

**Abstract:**

**Keywords:**
Binder,
casting,
metakaolin,
rice polishing cylinder.

##### 177 Experimental Measurements of Mean and Turbulence Quantities behind the Circular Cylinder by Attaching Different Number of Tripping Wires

**Authors:**
Amir Bak Khoshnevis,
Mahdieh Khodadadi,
Aghil Lotfi

**Abstract:**

For a bluff body, roughness elements in simulating a turbulent boundary layer, leading to delayed flow separation, a smaller wake, and lower form drag. In the present work, flow past a circular cylinder with using tripping wires is studied experimentally. The wind tunnel used for modeling free stream is open blow circuit (maximum speed = 30m/s and maximum turbulence of free stream = 0.1%). The selected Reynolds number for all tests was constant (Re = 25000). The circular cylinder selected for this experiment is 20 and 400mm in diameter and length, respectively. The aim of this research is to find the optimal operation mode. In this study installed some tripping wires 1mm in diameter, with a different number of wires on the circular cylinder and the wake characteristics of the circular cylinder is studied. Results showed that by increasing number of tripping wires attached to the circular cylinder (6, 8, and 10, respectively), The optimal angle for the tripping wires with 1mm in diameter to be installed on the cylinder is 60̊ (or 6 wires required at angle difference of 60̊). Strouhal number for the cylinder with tripping wires 1mm in diameter at angular position 60̊ showed the maximum value.

**Keywords:**
Wake of a circular cylinder,
trip wire,
velocity defect,
Strouhal number.

##### 176 Vortex-Induced Vibration Characteristics of an Elastic Circular Cylinder

**Authors:**
T. Li,
J.Y. Zhang,
W.H. Zhang,
M.H. Zhu

**Abstract:**

**Keywords:**
Fluid-structure interaction,
Navier-Stokes equation,
Space-time finite element method,
vortex-induced vibration.

##### 175 Bond Graph Modeling of Inter-Actuator Interactions in a Multi-Cylinder Hydraulic System

**Authors:**
Mutuku Muvengei,
John Kihiu

**Abstract:**

**Keywords:**
Bond graphs,
Inter-actuator interactions,
Valvecontrolledhydraulic cylinder.

##### 174 Experimental and Numerical Studies of Drag Reduction on a Circular Cylinder

**Authors:**
A.O. Ladjedel,
B.T.Yahiaoui,
C.L.Adjlout,
D.O.Imine

**Abstract:**

**Keywords:**
Circular cylinder,
Drag,
grooves,
pressure
distribution

##### 173 Steady State Creep Behavior of Functionally Graded Thick Cylinder

**Authors:**
Tejeet Singh,
Harmanjit Singh

**Abstract:**

Creep behavior of thick-walled functionally graded cylinder consisting of AlSiC and subjected to internal pressure and high temperature has been analyzed. The functional relationship between strain rate with stress can be described by the well known threshold stress based creep law with a stress exponent of five. The effect of imposing non-linear particle gradient on the distribution of creep stresses in the thick-walled functionally graded composite cylinder has been investigated. The study revealed that for the assumed non-linear particle distribution, the radial stress decreases throughout the cylinder, whereas the tangential, axial and effective stresses have averaging effect. The strain rates in the functionally graded composite cylinder could be reduced to significant extent by employing non-linear gradient in the distribution of reinforcement.

**Keywords:**
Functionally Graded Material,
Pressure,
Steady State Creep,
Thick-Cylinder.

##### 172 Heat Transfer from Two Cam Shaped Cylinders in Tandem Arrangement

**Authors:**
Arash Mir Abdolah Lavasani,
Hamidreza Bayat

**Abstract:**

Heat transfer from two cam shape cylinder in tandem arrangement had been studied numerically. The distance between the centers of cylinders (L) is allowed to vary to change the longitudinal pitch ratio (L/Deq). The equivalent diameter of the cylinder (Deq) is 27.6 mm and longitudinal pitch ratio varies in range 2<L/Deq<6. The Reynolds number based on equivalent circular cylinder are within 50< Reeq <300. Results show that Nusselt number of second cylinder increases about 5 to 33 times when longitudinal pitch ratio increases from 2 to 6.

**Keywords:**
Cam Shaped,
tandem Cylinders,
Numerical,
Heat
Transfer.

##### 171 Dynamics of a Vapour Bubble inside a Vertical Rigid Cylinder in the Absence of Buoyancy Forces

**Authors:**
S. Mehran,
S. Rouhi,
F.Rouzbahani,
E. Haghgoo

**Abstract:**

**Keywords:**
Vapour bubble,
Vertical rigid cylinder,
Boundaryelement method,
Finite difference method,
Buoyancy forces.

##### 170 Axisymmetric Vibration of Pyrocomposite Hollow Cylinder

**Authors:**
V. K. Nelson,
S. Karthikeyan

**Abstract:**

**Keywords:**
Axisymmetric vibration,
CFRP,
hollow cylinders,
LEMV,
pyrocomposite

##### 169 Numerical Investigation of the Effect of Flow and Heat Transfer of a Semi-Cylindrical Obstacle Located in a Channel

**Authors:**
Omer F. Can,
Nevin Celik

**Abstract:**

**Keywords:**
External flow,
semi-cylinder obstacle,
heat transfer,
friction.

##### 168 Investigation of Self-Similarity Solution for Wake Flow of a Cylinder

**Authors:**
A. B. Khoshnevis,
F. Zeydabadi,
F. Sokhanvar

**Abstract:**

**Keywords:**
Self-similarity,
wake of single circular cylinder

##### 167 Effects of Electric Potential on Thermo-Mechanical Behavior of Functionally Graded Piezoelectric Hollow Cylinder under Non-Axisymmetric Loads

**Authors:**
Amir Atrian,
Javad Jafari Fesharaki,
Gh. Hossein Majzoobi,
Mahsa Sheidaee

**Abstract:**

**Keywords:**
Analytical,
FGM,
Fourier series,
Non-axisymmetric,
Piezoelectric,
Thermo-elasticity

##### 166 Unsteady Temperature Distribution in a Finite Functionally Graded Cylinder

**Authors:**
A. Amiri Delouei

**Abstract:**

In the current study, two-dimensional unsteady heat conduction in a functionally graded cylinder is studied analytically. The temperature distribution is in radial and longitudinal directions. Heat conduction coefficients are considered a power function of radius both in radial and longitudinal directions. The proposed solution can exactly satisfy the boundary conditions. Analytical unsteady temperature distribution for different parameters of functionally graded cylinder is investigated. The achieved exact solution is useful for thermal stress analysis of functionally graded cylinders. Regarding the analytical approach, this solution can be used to understand the concepts of heat conduction in functionally graded materials.

**Keywords:**
Functionally graded materials,
unsteady heat conduction,
cylinder,
Temperature distribution.

##### 165 Experimental Study of Frequency Behavior for a Circular Cylinder behind an Airfoil

**Authors:**
S. Bajalan,
A. Shadaram,
N. Hedayat,
A. Shams Taleghani

**Abstract:**

**Keywords:**
Airfoil,
Cylinder,
Strouhal,
Wake interaction

##### 164 Heat Transfer from a Cylinder in Cross-Flow of Single and Multiphase Flows

**Authors:**
F. A. Hamad,
S. He

**Abstract:**

**Keywords:**
Circular cylinder,
cross-flow,
heat transfer,
multicomponent multiphase flow.

##### 163 Heat Transfer from Two Cam Shaped Cylinders in Side-by-Side Arrangement

**Authors:**
Arash Mir Abdolah Lavasani,
Hamidreza Bayat

**Abstract:**

**Keywords:**
Cam shaped,
side-by-side cylinders,
numerical,
heat
Transfer.

##### 162 An Investigation on the Effects of Injection Spray Cone on Propulsive Droplets in a Duct

**Authors:**
M. Mojtahedpoor

**Abstract:**

**Keywords:**
Ramjet,
droplet sizing,
injection velocity,
air flowvelocity,
efficient mass fraction..

##### 161 Numerical Analysis of Laminar Flow around Square Cylinders with EHD Phenomenon

**Authors:**
M. Salmanpour,
O. Nourani Zonouz

**Abstract:**

In this research, a numerical simulation of an Electrohydrodynamic (EHD) actuator’s effects on the flow around a square cylinder by using a finite volume method has been investigated. This is one of the newest ways for controlling the fluid flows. Two plate electrodes are flush-mounted on the surface of the cylinder and one wire electrode is placed on the line with zero angle of attack relative to the stagnation point and excited with DC power supply. The discharge produces an electric force and changes the local momentum behaviors in the fluid layers. For this purpose, after selecting proper domain and boundary conditions, the electric field relating to the problem has been analyzed and then the results in the form of electrical body force have been entered in the governing equations of fluid field (Navier-Stokes equations). The effect of ionic wind resulted from the Electrohydrodynamic actuator, on the velocity, pressure and the wake behind cylinder has been considered. According to the results, it is observed that the fluid flow accelerates in the nearest wall of the frontal half of the cylinder and the pressure difference between frontal and hinder cylinder is increased.

**Keywords:**
CFD,
corona discharge,
electro hydrodynamics,
flow around square cylinders.

##### 160 Effects of Injection Velocity and Entrance Airflow Velocity on Droplets Sizing in a Duct

**Authors:**
M. M. Doustdar ,
M. Mojtahedpoor

**Abstract:**

**Keywords:**
Ramjet,
droplet sizing,
injection velocity,
air flow
velocity,
efficient mass fraction.

##### 159 Hybrid RANS-LES Simulation of In-Cylinder Air Flow for Different Engine Speeds at Fixed Intake Flow Pressure

**Authors:**
L. V. Fui,
A. Ulugbek,
S. S. Dol

**Abstract:**

The in-cylinder flow and mixture formations are significant in view of today’s increasing concern on environmental issues and stringent emission regulations. In this paper, the numerical simulations of a SI engine at different engine speeds (2000-5000 rpm) at fixed intake flow pressure of 1 bar are studied using the AVL FIRE software. The simulation results show that when the engine speed at fixed intake flow pressure is increased, the volumetric efficiency of the engine decreases. This is due to a richer fuel conditions near the engine cylinder wall when engine speed is increased. Significant effects of impingement are also noted on the upper and side walls of the engine cylinder. These variations in mixture formation before ignition could affect the thermodynamics efficiency and specific fuel consumption that would lead to a reduced engine performance.

**Keywords:**
AVL FIRE,
fuel mass,
IC engine,
LES,
RANS,
turbulent intensity.

##### 158 Mixed Convection Enhancement in a 3D Lid-Driven Cavity Containing a Rotating Cylinder by Applying an Artificial Roughness

**Authors:**
Ali Khaleel Kareem,
Shian Gao,
Ahmed Qasim Ahmed

**Abstract:**

**Keywords:**
Artificial roughness,
Lid-driven cavity,
Mixed convection heat transfer,
Rotating cylinder,
URANS method.

##### 157 Analysis of the Secondary Stationary Flow Around an Oscillating Circular Cylinder

**Authors:**
Artem Nuriev,
Olga Zaitseva

**Abstract:**

This paper is devoted to the study of a viscous incompressible flow around a circular cylinder performing harmonic oscillations, especially the steady streaming phenomenon. The research methodology is based on the asymptotic explanation method combined with the computational bifurcation analysis. The research approach develops Schlichting and Wang decomposition method. Present studies allow to identify several regimes of the secondary streaming with different flow structures. The results of the research are in good agreement with experimental and numerical simulation data.

**Keywords:**
Oscillating cylinder,
Secondary Streaming,
Flow
Regimes,
Asymptotic and Bifurcation Analysis.

##### 156 Experimental and Numerical Study of The Shock-Accelerated Elliptic Heavy Gas Cylinders

**Authors:**
Jing S. Bai,
Li Y. Zou,
Tao Wang,
Kun Liu,
Wen B. Huang,
Jin H. Liu,
Ping Li,
Duo W. Tan,
CangL. Liu

**Abstract:**

**Keywords:**
About four key words or phrases in alphabeticalorder,
separated by commas.

##### 155 Stress Analysis for Two Fitted Thin Walled Cylinder with High Angular Velocity

**Authors:**
A.V. Hoseini,
A. Bidi,
M. H. Pol,
M.Jalali azizpour

**Abstract:**

**Keywords:**
Thin walled cylinder,
high angular velocity,
twofitted thin walled