**Commenced**in January 2007

**Frequency:**Monthly

**Edition:**International

**Paper Count:**4237

# Search results for: flow function

##### 4237 A Transfer Function Representation of Thermo-Acoustic Dynamics for Combustors

**Authors:**
Myunggon Yoon,
Jung-Ho Moon

**Abstract:**

**Keywords:**
Thermoacoustics,
dynamics,
combustor,
transfer
function.

##### 4236 The Effects of Rain and Overland Flow Powers on Agricultural Soil Erodibility

**Authors:**
A. Moussouni,
L. Mouzai,
M. Bouhadef

**Abstract:**

**Keywords:**
Laboratory experiments,
soil erosion,
flow power,
erodibility,
rainfall intensity.

##### 4235 The Design of Axisymmetric Ducts for Incompressible Flow with a Parabolic Axial Velocity Inlet Profile

**Authors:**
V.Pavlika

**Abstract:**

In this paper a numerical algorithm is described for solving the boundary value problem associated with axisymmetric, inviscid, incompressible, rotational (and irrotational) flow in order to obtain duct wall shapes from prescribed wall velocity distributions. The governing equations are formulated in terms of the stream function ψ (x,y)and the function φ (x,y)as independent variables where for irrotational flow φ (x,y)can be recognized as the velocity potential function, for rotational flow φ (x,y)ceases being the velocity potential function but does remain orthogonal to the stream lines. A numerical method based on the finite difference scheme on a uniform mesh is employed. The technique described is capable of tackling the so-called inverse problem where the velocity wall distributions are prescribed from which the duct wall shape is calculated, as well as the direct problem where the velocity distribution on the duct walls are calculated from prescribed duct geometries. The two different cases as outlined in this paper are in fact boundary value problems with Neumann and Dirichlet boundary conditions respectively. Even though both approaches are discussed, only numerical results for the case of the Dirichlet boundary conditions are given. A downstream condition is prescribed such that cylindrical flow, that is flow which is independent of the axial coordinate, exists.

**Keywords:**
Inverse problem,
irrotational incompressible flow,
Boundary value problem.

##### 4234 A Case Study to Assess the Validity of Function Points

**Authors:**
Neelam Bawane nee' Singhal,
C. V. Srikrishna

**Abstract:**

**Keywords:**
Function Points,
Data Flow Diagram,
Lines ofCodes.

##### 4233 Roles of Aquatic Plants on Erosion Relief of Stream Bed

**Authors:**
Jin-Hong Kim

**Abstract:**

**Keywords:**
Aquatic plants,
Phragmites japonica,
Phragmites
communis,
Miscanthus sacchariflorus,
Salix gracilistyla.

##### 4232 Numerical Study of Flow Separation Control over a NACA2415 Airfoil

**Authors:**
M. Tahar Bouzaher

**Abstract:**

This study involves numerical simulation of the flow around a NACA2415 airfoil, with a 18° angle of attack, and flow separation control using a rod, It involves putting a cylindrical rod - upstream of the leading edge- in vertical translation movement in order to accelerate the transition of the boundary layer by interaction between the rod wake and the boundary layer. The viscous, nonstationary flow is simulated using ANSYS FLUENT 13. The rod movement is reproduced using the dynamic mesh technique and an in-house developed UDF (User Define Function). The frequency varies from 75 to 450 Hz and the considered amplitudes are 2%, and 3% of the foil chord. The frequency chosen closed to the frequency of separation. Our results showed a substantial modification in the flow behavior and a maximum drag reduction of 61%.

**Keywords:**
CFD,
Flow separation,
Active control,
Boundary
layer,
rod,
NACA 2415.

##### 4231 Another Approach of Similarity Solution in Reversed Stagnation-point Flow

**Authors:**
Vai Kuong Sin,
Chon Kit Chio

**Abstract:**

**Keywords:**
reversed stagnation-point flow,
similarity solutions,
asymptotic solution

##### 4230 Numerical Investigation of Flow Past Cylinderin Cross Flow

**Authors:**
M. H. Alhajeri,
Jasem Alrajhi,
Mohsen Alardhi,
Saleh Alhajeri

**Abstract:**

A numerical prediction of flow in a tube bank is reported. The flow regimes considered cover a wide range of Reynolds numbers, which range from 380 to 99000 and which are equivalent to a range of inlet velocities from very low (0.072 m/s) to very high (60 m/s). In this study, calculations were made using the standard k-e model with standard wall function. The drag coefficient, skin friction drag, pressure drag, and pressure distribution around a tube were investigated. As the velocity increased, the drag coefficient decreased until the velocity exceeded 45 m/s, after which it increased. Furthermore, the pressure drag and skin friction drag depend on the velocity.

**Keywords:**
Numerical,
Fluid,
Flow,
Turbine,
Cooling,
Blade.

##### 4229 Effect of Secondary Curvature on Mixing Characteristic within Constant Circular Tubes

**Authors:**
Minh Tuan Nguyen,
Sang-Wook Lee

**Abstract:**

**Keywords:**
Secondary curvature,
Sinusoidal wavy tubes,
Mixing
Characteristics,
Pulsatile flow,
Hemodynamics.

##### 4228 Unified Gas-Kinetic Scheme for Gas-Particle Flow in Shock-Induced Fluidization of Particles Bed

**Abstract:**

**Keywords:**
Gas-particle flow,
unified gas-kinetic scheme,
momentum transfer,
shock-induced fluidization.

##### 4227 Solution of Fuzzy Maximal Flow Problems Using Fuzzy Linear Programming

**Authors:**
Amit Kumar,
Manjot Kaur

**Abstract:**

**Keywords:**
Fuzzy linear programming,
Fuzzy maximal flow problem,
Ranking function,
Triangular fuzzy number

##### 4226 A MATLAB Simulink Library for Transient Flow Simulation of Gas Networks

**Authors:**
M. Behbahani-Nejad,
A. Bagheri

**Abstract:**

**Keywords:**
Gas network,
MATLAB-Simulink,
transfer
functions,
transient flow.

##### 4225 A Review on Hydraulic and Morphological Characteristics in River Channels Due to Spurs

**Authors:**
M. Alauddin,
M. M. Hossain,
M. N. Uddin,
M. E. Haque

**Abstract:**

**Keywords:**
Bed topography,
flow pattern,
scour,
spur.

##### 4224 Flow Transformation: An Investigation on Theoretical Aspects and Numerical Computation

**Authors:**
Abhisek Sarkar,
Abhimanyu Gaur

**Abstract:**

In this report we have discussed the theoretical aspects of the flow transformation, occurring through a series of bifurcations. The parameters and their continuous diversion, the intermittent bursts in the transition zone, variation of velocity and pressure with time, effect of roughness in turbulent zone, and changes in friction factor and head loss coefficient as a function of Reynolds number for a transverse flow across a cylinder have been discussed. An analysis of the variation in the wake length with Reynolds number was done in FORTRAN.

**Keywords:**
Attractor,
Bifurcation,
Energy cascade,
Energy
spectra,
Intermittence,
Vortex stretching.

##### 4223 Flow Regime Characterization in a Diseased Artery Model

**Authors:**
Anis S. Shuib,
Peter R. Hoskins,
William J. Easson

**Abstract:**

Cardiovascular disease mostly in the form of atherosclerosis is responsible for 30% of all world deaths amounting to 17 million people per year. Atherosclerosis is due to the formation of plaque. The fatty plaque may be at risk of rupture, leading typically to stroke and heart attack. The plaque is usually associated with a high degree of lumen reduction, called a stenosis. The initiation and progression of the disease is strongly linked to the hemodynamic environment near the vessel wall. The aim of this study is to validate the flow of blood mimic through an arterial stenosis model with computational fluid dynamics (CFD) package. In experiment, an axisymmetric model constructed consists of contraction and expansion region that follow a mathematical form of cosine function. A 30% diameter reduction was used in this study. Particle image velocimetry (PIV) was used to characterize the flow. The fluid consists of rigid spherical particles suspended in waterglycerol- NaCl mixture. The particles with 20 μm diameter were selected to follow the flow of fluid. The flow at Re=155, 270 and 390 were investigated. The experimental result is compared with FLUENT simulated flow that account for viscous laminar flow model. The results suggest that laminar flow model was sufficient to predict flow velocity at the inlet but the velocity at stenosis throat at Re =390 was overestimated. Hence, a transition to turbulent regime might have been developed at throat region as the flow rate increases.

**Keywords:**
Atherosclerosis,
Particle-laden flow,
Particle imagevelocimetry,
Stenosis artery

##### 4222 A Note on MHD Flow and Heat Transfer over a Curved Stretching Sheet by Considering Variable Thermal Conductivity

**Authors:**
M. G. Murtaza,
E. E. Tzirtzilakis,
M. Ferdows

**Abstract:**

The mixed convective flow of MHD incompressible, steady boundary layer in heat transfer over a curved stretching sheet due to temperature dependent thermal conductivity is studied. We use curvilinear coordinate system in order to describe the governing flow equations. Finite difference solutions with central differencing have been used to solve the transform governing equations. Numerical results for the flow velocity and temperature profiles are presented as a function of the non-dimensional curvature radius. Skin friction coefficient and local Nusselt number at the surface of the curved sheet are discussed as well.

**Keywords:**
Curved stretching sheet,
finite difference method,
MHD,
variable thermal conductivity.

##### 4221 An Extension of the Kratzel Function and Associated Inverse Gaussian Probability Distribution Occurring in Reliability Theory

**Authors:**
R. K. Saxena,
Ravi Saxena

**Abstract:**

In view of their importance and usefulness in reliability theory and probability distributions, several generalizations of the inverse Gaussian distribution and the Krtzel function are investigated in recent years. This has motivated the authors to introduce and study a new generalization of the inverse Gaussian distribution and the Krtzel function associated with a product of a Bessel function of the third kind )(zKQ and a Z - Fox-Wright generalized hyper geometric function introduced in this paper. The introduced function turns out to be a unified gamma-type function. Its incomplete forms are also discussed. Several properties of this gamma-type function are obtained. By means of this generalized function, we introduce a generalization of inverse Gaussian distribution, which is useful in reliability analysis, diffusion processes, and radio techniques etc. The inverse Gaussian distribution thus introduced also provides a generalization of the Krtzel function. Some basic statistical functions associated with this probability density function, such as moments, the Mellin transform, the moment generating function, the hazard rate function, and the mean residue life function are also obtained.KeywordsFox-Wright function, Inverse Gaussian distribution, Krtzel function & Bessel function of the third kind.

**Keywords:**
Fox-Wright function,
Inverse Gaussian distribution,
Krtzel function & Bessel function of the third kind.

##### 4220 Numerical Solution of Manning's Equation in Rectangular Channels

**Authors:**
Abdulrahman Abdulrahman

**Abstract:**

**Keywords:**
Channel design,
civil engineering,
hydraulic engineering,
open channel flow,
Manning's equation,
normal depth,
uniform flow.

##### 4219 Analysis of Slip Flow Heat Transfer between Asymmetrically Heated Parallel Plates

**Authors:**
Hari Mohan Kushwaha,
Santosh K. Sahu

**Abstract:**

**Keywords:**
Knudsen Number,
Modified Brinkman Number,
Slip
Flow,
Velocity Slip.

##### 4218 Enhanced Particle Swarm Optimization Approach for Solving the Non-Convex Optimal Power Flow

**Authors:**
M. R. AlRashidi,
M. F. AlHajri,
M. E. El-Hawary

**Abstract:**

**Keywords:**
Particle Swarm Optimization,
Optimal Power Flow,
Economic Dispatch.

##### 4217 Analysis Fraction Flow of Water versus Cumulative Oil Recoveries Using Buckley Leverett Method

**Authors:**
Reza Cheraghi Kootiani,
Ariffin Bin Samsuri

**Abstract:**

**Keywords:**
Fractional Flow,
Fluid Saturations,
Permeability,
Cumulative Oil Recoveries,
Buckley Leverett Method.

##### 4216 Flow Acoustics in Solid-Fluid Structures

**Authors:**
Morten Willatzen,
Mikhail Vladimirovich Deryabin

**Abstract:**

The governing two-dimensional equations of a heterogeneous material composed of a fluid (allowed to flow in the absence of acoustic excitations) and a crystalline piezoelectric cubic solid stacked one-dimensionally (along the z direction) are derived and special emphasis is given to the discussion of acoustic group velocity for the structure as a function of the wavenumber component perpendicular to the stacking direction (being the x axis). Variations in physical parameters with y are neglected assuming infinite material homogeneity along the y direction and the flow velocity is assumed to be directed along the x direction. In the first part of the paper, the governing set of differential equations are derived as well as the imposed boundary conditions. Solutions are provided using Hamilton-s equations for the wavenumber vs. frequency as a function of the number and thickness of solid layers and fluid layers in cases with and without flow (also the case of a position-dependent flow in the fluid layer is considered). In the first part of the paper, emphasis is given to the small-frequency case. Boundary conditions at the bottom and top parts of the full structure are left unspecified in the general solution but examples are provided for the case where these are subject to rigid-wall conditions (Neumann boundary conditions in the acoustic pressure). In the second part of the paper, emphasis is given to the general case of larger frequencies and wavenumber-frequency bandstructure formation. A wavenumber condition for an arbitrary set of consecutive solid and fluid layers, involving four propagating waves in each solid region, is obtained again using the monodromy matrix method. Case examples are finally discussed.

**Keywords:**
Flow,
acoustics,
solid-fluid structures,
periodicity.

##### 4215 Measurement of Reverse Flow Generated at Cold Exit of Vortex Tube

**Authors:**
Mohd Hazwan bin Yusof,
Hiroshi Katanoda

**Abstract:**

In order to clarify the structure of the cold flow discharged from the vortex tube (VT), the pressure of the cold flow was measured, and a simple flow visualization technique using a 0.75mm-diameter needle and an oily paint is made to study the reverse flow at the cold exit. It is clear that a negative pressure and positive pressure region exist at a certain pressure and cold fraction area, and that a reverse flow is observed in the negative pressure region.

**Keywords:**
Flow visualization,
Pressure measurement,
Reverse flow,
Vortex tube.

##### 4214 Numerical Study of Microscale Gas Flow-Separation Using Explicit Finite Volume Method

**Authors:**
A. Chaudhuri,
C. Guha,
T. K. Dutta

**Abstract:**

**Keywords:**
AUSM+,
FVM,
Flow-separation,
Microflow.

##### 4213 Hydrological Method to Evaluate Environmental Flow (Case Study: Gharasou River, Ardabil)

**Authors:**
Mehdi Fuladipanah,
Mehdi Jorabloo

**Abstract:**

Water flow management is one of the most important parts of river engineering. Non-uniformity distribution of rainfall and various flow demand with unreasonable flow management will be caused destroyed of river ecosystem. Then, it is very serious to determine ecosystem flow requirement. In this paper, Flow duration curve indices method which has hydrological based was used to evaluate environmental flow in Gharasou River, Ardabil, Iran. Using flow duration curve, Q90 and Q95 for different return periods were calculated. Their magnitude were determined as 1-day, 3-day, 7-day and 30 day. According the second method, hydraulic alteration indices often had low and medium range. In order to maintain river at an acceptable ecological condition, minimum daily discharge of index Q95 is 0.7 m3.s-1.

**Keywords:**
Ardabil,
Environmental flow,
Flow Duration Curve,
Gharasou River.

##### 4212 File Format of Flow Chart Simulation Software - CFlow

**Authors:**
Syahanim Mohd Salleh,
Zaihosnita Hood,
Hairulliza Mohd Judi,
Marini Abu Bakar

**Abstract:**

**Keywords:**
CFlow,
flow chart,
file format.

##### 4211 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.

##### 4210 Oil Displacement by Water in Hauterivian Sandstone Reservoir of Kashkari Oil Field

**Authors:**
A. J. Nazari,
S. Honma

**Abstract:**

This paper evaluates oil displacement by water in Hauterivian sandstone reservoir of Kashkari oil field in North of Afghanistan. The core samples of this oil field were taken out from well No-21^{st}, and the relative permeability and fractional flow are analyzed. Steady state flow laboratory experiments are performed to empirically obtain the fractional flow curves and relative permeability in different water saturation ratio. The relative permeability represents the simultaneous flow behavior in the reservoir. The fractional flow approach describes the individual phases as fractional of the total flow. The fractional flow curve interprets oil displacement by water, and from the tangent of fractional flow curve can find out the average saturation behind the water front flow saturation. Therefore, relative permeability and fractional flow curves are suitable for describing the displacement of oil by water in a petroleum reservoir. The effects of irreducible water saturation, residual oil saturation on the displaceable amount of oil are investigated through Buckley-Leveret analysis.

**Keywords:**
Fractional flow,
oil displacement,
relative permeability,
simultaneously flow.

##### 4209 Estimating the Flow Velocity Using Flow Generated Sound

**Authors:**
Saeed Hosseini,
Ali Reza Tahavvor

**Abstract:**

**Keywords:**
Flow generated sound,
sound processing,
speed,
wave power.

##### 4208 Wetting Front Propagation during Quenching of Aluminum Plate by Water Spray

**Authors:**
M. M. Seraj,
M. S. Gadala

**Abstract:**

This study presents a systematic analysis of wetted region due to cooling of aluminum plate by water spray impingement with respect to different water flow rates, spray nozzle heights, and subcooling. Unlike jet impingement, the wetting is not commenced upon spray impingement and there is a delay in wetness of hot test surface. After initiation, the wetting (black zone) progresses gradually to cover all test plate and provides efficient cooling in nucleate boiling regime. Generally, spray cooling is found function of spray flow rate, spray-to-surface distance and water subcooling. Wetting delay is decreasing by increasing of spray flow rate until spray impact area is not become bigger that test surface. Otherwise, higher spray flow rate is not practically accelerated start of wetting. Very fast wetting due to spray cooling can be obtained by dense spray (high floe rate) discharged from adjacent nozzle to the test surface. Highly subcooling water spray also triggers earlier wetting of hot aluminum plate.

**Keywords:**
Water spray,
wetting,
aluminum plate,
flow rate.