**Commenced**in January 2007

**Frequency:**Monthly

**Edition:**International

**Paper Count:**421

# Search results for: Boundary Layer

##### 421 PIV Investigation into the Evolution of Vortical Structures in the Zero Pressure Gradient Boundary Layer

**Authors:**
Ishtiaq A. Chaudhry,
Zia R. Tahir

**Abstract:**

**Keywords:**
Boundary layer,
synthetic jet actuator,
flow
separation control,
vortical structures.

##### 420 Numerical Investigation of Two-dimensional Boundary Layer Flow Over a Moving Surface

**Authors:**
Mahmoud Zarrini,
R.N. Pralhad

**Abstract:**

In this chapter, we have studied Variation of velocity in incompressible fluid over a moving surface. The boundary layer equations are on a fixed or continuously moving flat plate in the same or opposite direction to the free stream with suction and injection. The boundary layer equations are transferred from partial differential equations to ordinary differential equations. Numerical solutions are obtained by using Runge-Kutta and Shooting methods. We have found numerical solution to velocity and skin friction coefficient.

**Keywords:**
Boundary layer,
continuously moving surface,
shooting method,
skin friction coefficient.

##### 419 A Study of Various Numerical Turbulence Modeling Methods in Boundary Layer Excitation of a Square Ribbed Channel

**Authors:**
Hojjat Saberinejad,
Adel Hashiehbaf,
Ehsan Afrasiabian

**Abstract:**

**Keywords:**
boundary layer,
turbulence,
numerical method,
rib
cooling

##### 418 Magnetohydrodynamics Boundary Layer Flows over a Stretching Surface with Radiation Effect and Embedded in Porous Medium

**Authors:**
Siti Khuzaimah Soid,
Zanariah Mohd Yusof,
Ahmad Sukri Abd Aziz,
Seripah Awang Kechil

**Abstract:**

**Keywords:**
Keller-box,
MHD boundary layer flow,
permeability
stretching.

##### 417 Cooling Turbine Blades using Exciting Boundary Layer

**Authors:**
Ali Ghobadi,
Seyed Mohammad Javadi,
Behnam Rahimi

**Abstract:**

**Keywords:**
Cooling,
Exciting Boundary Layer,
Heat Transfer,
Turbine Blade.

##### 416 CFD Analysis of a Centrifugal Fan for Performance Enhancement using Converging Boundary Layer Suction Slots

**Authors:**
K. Vasudeva Karanth,
N. Yagnesh Sharma

**Abstract:**

**Keywords:**
Boundary layer suction converging slot,
Flowseparation,
Sliding mesh,
Unsteady analysis,
Recirculation zone,
Jetsand wakes.

##### 415 Experimental and Numerical Investigation of Air Ejector with Diffuser with Boundary Layer Suction

**Authors:**
Vaclav Dvorak

**Abstract:**

**Keywords:**
Air ejector,
boundary layer suction,
CFD,
diffuser.

##### 414 Wall Pressure Fluctuations in Naturally Developing Boundary Layer Flows on Axisymmetric Bodies

**Authors:**
Chinsuk Hong

**Abstract:**

**Keywords:**
Wall Pressure Fluctuation,
Boundary Layer Flow,
Transition,
Turbulent Flow,
Axisymmetric Body,
Flow Noise.

##### 413 A Wall Law for Two-Phase Turbulent Boundary Layers

**Authors:**
Dhahri Maher,
Aouinet Hana

**Abstract:**

**Keywords:**
Bubbly flows,
log law,
boundary layer.

##### 412 Fuzzy Boundary Layer Solution to Nonlinear Hydraulic Position Control Problem

**Authors:**
Mustafa Resa Becan

**Abstract:**

Sliding mode control with a fuzzy boundary layer is presented to hydraulic position control problem in this paper. A nonlinear hydraulic servomechanism which has an asymmetric cylinder is modeled and simulated first, then the proposed control scheme is applied to this model versus the conventional sliding mode control. Simulation results proved that the chattering free position control is achieved by tuning the fuzzy scaling factors properly.

**Keywords:**
Hydraulic servomechanism,
position control,
sliding mode control,
chattering,
fuzzy boundary layer.

##### 411 Water Boundary Layer Flow Over Rotating Sphere with Mass Transfer

**Authors:**
G. Revathi,
P. Saikrishnan

**Abstract:**

An analysis is performed to study the influence of nonuniform double slot suction on a steady laminar boundary layer flow over a rotating sphere when fluid properties such as viscosity and Prandtl number are inverse linear functions of temperature. Nonsimilar solutions have been obtained from the starting point of the streamwise co-ordinate to the exact point of separation. The difficulties arising at the starting point of the streamwise co-ordinate, at the edges of the slot and at the point of separation have been overcome by applying an implicit finite difference scheme in combination with the quasi-linearization technique and an appropriate selection of the finer step sizes along the stream-wise direction. The present investigation shows that the point of ordinary separation can be delayed by nonuniform double slot suction if the mass transfer rate is increased and also if the slots are positioned further downstream. In addition, the investigation reveals that double slot suction is found to be more effective compared to a single slot suction in delaying ordinary separation. As rotation parameter increase the point of separation moves upstream direction.

**Keywords:**
Boundary layer,
suction,
mass transfer,
rotating sphere.

##### 410 Numerical Solution of a Laminar Viscous Flow Boundary Layer Equation Using Uniform Haar Wavelet Quasi-linearization Method

**Authors:**
Harpreet Kaur,
Vinod Mishra,
R. C. Mittal

**Abstract:**

In this paper, we have proposed a Haar wavelet quasilinearization method to solve the well known Blasius equation. The method is based on the uniform Haar wavelet operational matrix defined over the interval [0, 1]. In this method, we have proposed the transformation for converting the problem on a fixed computational domain. The Blasius equation arises in the various boundary layer problems of hydrodynamics and in fluid mechanics of laminar viscous flows. Quasi-linearization is iterative process but our proposed technique gives excellent numerical results with quasilinearization for solving nonlinear differential equations without any iteration on selecting collocation points by Haar wavelets. We have solved Blasius equation for 1≤α ≤ 2 and the numerical results are compared with the available results in literature. Finally, we conclude that proposed method is a promising tool for solving the well known nonlinear Blasius equation.

**Keywords:**
Boundary layer Blasius equation,
collocation points,
quasi-linearization process,
uniform haar wavelets.

##### 409 Unsteady Boundary Layer Flow over a Stretching Sheet in a Micropolar Fluid

**Authors:**
Roslinda Nazar,
Anuar Ishak,
Ioan Pop

**Abstract:**

**Keywords:**
Boundary layer,
micropolar fluid,
stretching surface,
unsteady flow.

##### 408 Unsteady Water Boundary Layer Flow with Non-Uniform Mass Transfer

**Authors:**
G. Revathi,
P. Saikrishnan

**Abstract:**

**Keywords:**
Boundary layer,
heat transfer,
non-similar solution,
non-uniform mass,
unsteady flow.

##### 407 A Modified Laplace Decomposition Algorithm Solution for Blasius’ Boundary Layer Equation of the Flat Plate in a Uniform Stream

**Authors:**
M. A. Koroma,
Z. Chuangyi,
A. F.,
Kamara,
A. M. H. Conteh

**Abstract:**

In this work, we apply the Modified Laplace decomposition algorithm in finding a numerical solution of Blasius’ boundary layer equation for the flat plate in a uniform stream. The series solution is found by first applying the Laplace transform to the differential equation and then decomposing the nonlinear term by the use of Adomian polynomials. The resulting series, which is exactly the same as that obtained by Weyl 1942a, was expressed as a rational function by the use of diagonal padé approximant.

**Keywords:**
Modified Laplace decomposition algorithm,
Boundary
layer equation,
Padé approximant,
Numerical solution.

##### 406 High-Speed Particle Image Velocimetry of the Flow around a Moving Train Model with Boundary Layer Control Elements

**Authors:**
Alexander Buhr,
Klaus Ehrenfried

**Abstract:**

**Keywords:**
Boundary layer,
high-speed PIV,
ICE3,
moving train
model,
roughness elements.

##### 405 Numerical Simulations of Acoustic Imaging in Hydrodynamic Tunnel with Model Adaptation and Boundary Layer Noise Reduction

**Authors:**
Sylvain Amailland,
Jean-Hugh Thomas,
Charles Pézerat,
Romuald Boucheron,
Jean-Claude Pascal

**Abstract:**

**Keywords:**
Acoustic imaging,
boundary layer noise denoising,
inverse problems,
model adaptation.

##### 404 Natural Convection Boundary Layer Flow of a Viscoelastic Fluid on Solid Sphere with Newtonian Heating

**Authors:**
A.R.M. Kasim,
N.F. Mohammad,
Aurangzaib,
S. Sharidan

**Abstract:**

**Keywords:**
boundary layer flow,
Newtonian heating,
sphere,
viscoelastic fluid.

##### 403 Free Convection Boundary Layer Flow of a Viscoelastic Fluid in the Presence of Heat Generation

**Authors:**
Abdul Rahman Mohd Kasim,
Mohd Ariff Admon,
Sharidan Shafie

**Abstract:**

**Keywords:**
Free Convection,
Boundary Layer,
CircularCylinder,
Viscoelastic Fluid,
Heat Generation

##### 402 A Large-Eddy Simulation of Vortex Cell flow with Incoming Turbulent Boundary Layer

**Authors:**
Arpiruk Hokpunna,
Michael Manhart

**Abstract:**

**Keywords:**
Turbulent flow,
Large eddy simulations,
boundary layer and cavity flow,
vortex cell flow.

##### 401 Numerical Solutions of Boundary Layer Flow over an Exponentially Stretching/Shrinking Sheet with Generalized Slip Velocity

**Authors:**
Ezad Hafidz Hafidzuddin,
Roslinda Nazar,
Norihan M. Arifin,
Ioan Pop

**Abstract:**

In this paper, the problem of steady laminar boundary layer flow and heat transfer over a permeable exponentially stretching/shrinking sheet with generalized slip velocity is considered. The similarity transformations are used to transform the governing nonlinear partial differential equations to a system of nonlinear ordinary differential equations. The transformed equations are then solved numerically using the bvp4c function in MATLAB. Dual solutions are found for a certain range of the suction and stretching/shrinking parameters. The effects of the suction parameter, stretching/shrinking parameter, velocity slip parameter, critical shear rate and Prandtl number on the skin friction and heat transfer coefficients as well as the velocity and temperature profiles are presented and discussed.

**Keywords:**
Boundary Layer,
Exponentially Stretching/Shrinking
Sheet,
Generalized Slip,
Heat Transfer,
Numerical Solutions.

##### 400 Sliding Mode Control with Fuzzy Boundary Layer to Air-Air Interception Problem

**Authors:**
Mustafa Resa Becan

**Abstract:**

The performance of a type of fuzzy sliding mode control is researched by considering the nonlinear characteristic of a missile-target interception problem to obtain a robust interception process. The variable boundary layer by using fuzzy logic is proposed to reduce the chattering around the switching surface then is applied to the interception model which was derived. The performances of the sliding mode control with constant and fuzzy boundary layer are compared at the end of the study and the results are evaluated.

**Keywords:**
Sliding mode control,
fuzzy,
boundary layer,
interception problem.

##### 399 Mixed Convection Boundary Layer Flow from a Vertical Cone in a Porous Medium Filled with a Nanofluid

**Authors:**
Ezzah Liana Ahmad Fauzi,
Syakila Ahmad,
Ioan Pop

**Abstract:**

**Keywords:**
boundary layer,
mixed convection,
nanofluid,
porous
medium,
vertical cone.

##### 398 Investigation of Increasing the Heat Transfer from Flat Surfaces Using Boundary Layer Excitation

**Authors:**
M.H.Ghaffari

**Abstract:**

**Keywords:**
Cooling,
Heat transfer,
Turbulence,
Excitingboundary layer.

##### 397 Unsteady Laminar Boundary Layer Forced Flow in the Region of the Stagnation Point on a Stretching Flat Sheet

**Authors:**
A. T. Eswara

**Abstract:**

**Keywords:**
Forced flow,
Keller-box method,
Stagnation point,
Stretching flat sheet,
Unsteady laminar boundary layer,
Velocity ratio parameter.

##### 396 Boundary Layer Flow of a Casson Nanofluid past a Vertical Exponentially Stretching Cylinder in the Presence of a Transverse Magnetic Field with Internal Heat Generation/Absorption

**Authors:**
G. Sarojamma,
K. Vendabai

**Abstract:**

An analysis is carried out to investigate the effect of magnetic field and heat source on the steady boundary layer flow and heat transfer of a Casson nanofluid over a vertical cylinder stretching exponentially along its radial direction. Using a similarity transformation, the governing mathematical equations, with the boundary conditions are reduced to a system of coupled, non –linear ordinary differential equations. The resulting system is solved numerically by the fourth order Runge – Kutta scheme with shooting technique. The influence of various physical parameters such as Reynolds number, Prandtl number, magnetic field, Brownian motion parameter, thermophoresis parameter, Lewis number and the natural convection parameter are presented graphically and discussed for non – dimensional velocity, temperature and nanoparticle volume fraction. Numerical data for the skin – friction coefficient, local Nusselt number and the local Sherwood number have been tabulated for various parametric conditions. It is found that the local Nusselt number is a decreasing function of Brownian motion parameter Nb and the thermophoresis parameter Nt.

**Keywords:**
Casson nanofluid,
Boundary layer flow,
Internal heat
generation/absorption,
Exponentially stretching cylinder,
Heat
transfer,
Brownian motion,
Thermophoresis.

##### 395 A Frequency Dependence of the Phase Field Model in Laminar Boundary Layer with Periodic Perturbations

**Authors:**
Yasuo Obikane

**Abstract:**

**Keywords:**
Phase field model,
two phase flows,
Laminarboundary Layer

##### 394 Mixed Convection Boundary Layer Flows Induced by a Permeable Continuous Surface Stretched with Prescribed Skin Friction

**Authors:**
Mohamed Ali

**Abstract:**

**Keywords:**
Stretching surface,
Boundary layers,
Prescribed skin friction,
Suction or injection,
similarity solutions,
buoyancy effects.

##### 393 MHD Chemically Reacting Viscous Fluid Flow towards a Vertical Surface with Slip and Convective Boundary Conditions

**Authors:**
Ibrahim Yakubu Seini,
Oluwole Daniel Makinde

**Abstract:**

**Keywords:**
Boundary layer,
surface slip,
MHD flow,
chemical
reaction,
heat transfer,
mass transfer.

##### 392 Application of Novel Conserving Immersed Boundary Method to Moving Boundary Problem

**Authors:**
S. N. Hosseini,
S. M. H. Karimian

**Abstract:**

A new conserving approach in the context of Immersed Boundary Method (IBM) is presented to simulate one dimensional, incompressible flow in a moving boundary problem. The method employs control volume scheme to simulate the flow field. The concept of ghost node is used at the boundaries to conserve the mass and momentum equations. The Present method implements the conservation laws in all cells including boundary control volumes. Application of the method is studied in a test case with moving boundary. Comparison between the results of this new method and a sharp interface (Image Point Method) IBM algorithm shows a well distinguished improvement in both pressure and velocity fields of the present method. Fluctuations in pressure field are fully resolved in this proposed method. This approach expands the IBM capability to simulate flow field for variety of problems by implementing conservation laws in a fully Cartesian grid compared to other conserving methods.

**Keywords:**
Immersed Boundary Method,
conservation of mass and momentum laws,
moving boundary,
boundary condition.