FLUENT Tutorial

JURUSAN TEKNIK MESINFAKULTAS TEKNOLOGI INDUSTRI

INSTITUT TEKNOLOGI SEPULUH NOPEMBERSURABAYA

Oleh :

Wawan Aries Widodo, ST.MT.

Computational Fluid DynamicsCFD is use of computational methodsfor solving fluid engineering systems,including modeling (mathematical &Physics) and numerical methods(solvers, finite differences, and gridgenerations, etc.).

Purpose of CFD

The objective of CFD is to model the continuousfluids with Partial Differential Equations (PDEs) anddiscretize PDEs into an algebra problem, solve it,validate it and achieve simulation based designinstead of “build & test”.

Simulation of physical fluid phenomena that aredifficult to be measured by experiments: scalesimulations (full-scale ships, airplanes), hazards(explosions, radiations, pollution), physics (weatherprediction, planetary boundary layer, stellarevolution).

Numerical Modeling Mathematical physics problem formulation of fluid

engineering system Governing equations: Navier-Stokes equations

(momentum), continuity equation, pressure Poissonequation, energy equation, ideal gas law, combustions(chemical reaction equation), multi-phase flows(e.g.Rayleigh equation), and turbulent models (RANS, LES,DES).

Coordinates: Cartesian, cylindrical and sphericalcoordinates result in different form of governingequations

Initial conditions (initial guess of the solution) andBoundary Conditions (no-slip wall, free-surface, zero-gradient, symmetry, velocity/pressure inlet/outlet)

Flow conditions: Geometry approximation, domain,Reynolds Number, and Mach Number, etc.

CFD process

“CFD process” is the steps to set up a problem and run the code

1. Geometry : Create the geometry you want

2. Physics : fluid properties, viscous modeling and boundary conditions

3. Mesh : coarse, medium and fine meshes

4. Solve : different solvers and numerical methods

5. Report : time history of convergence of

6. Post-Processing : visualizations (contours, vectors), validation and verification

Perangkat Lunak FLUENTFLUENT adalah paket perangkat lunakcomputational fluid dynamics (CFD) yangdigunakan untuk mensimulasikan kasus-kasusaliran fluida.FLUENT menggunakan metoda finite-volumemethod untuk menyelesaikan persamaan yangdibangun untuk fluida. Hal tersebut mencakuppenggunaan berbagai model fisis sepertiincompressible atau compressible, inviscid atauviscous, laminar atau turbulent, dll.

Geometri dan pembuatan grid dibuat dengansoftware GAMBIT yang merupakan pemroses awalyang merupakan bagian dari software FLUENT.

Struktur Program FLUENT

GAMBIT• Geometry setup• 2D/3D mesh generation

Pre PDF

Calculation of PDFlook-up tables

FLUENT Mesh import & adoption

Phyisical models

Boundary conditions

Material Properties

Calculation

Postprocessing

T Grid• 2D Triangular mesh

• 3D Tetrahedral mesh

• 2D or 3D hybrid mesh

Other CAD/CAEPackages

MeshB

ound

ary

Mes

h

Boundary and/orVolume Mesh

PDFFiles

2D/3D Mesh

Mesh

PDF :Probability DensityFunction

Tahapan dalam PenggunaanSoftware FLUENT

1. Buat Geometri dengan GAMBIT2. Mesh Geometri dengan GAMBIT3. Tetapkan Tipe-Tipe Boundary dengan

GAMBIT4. Tetapkan Problem tersebut dengan

FLUENT5. Selesaikan dengan FLUENT6. Analisa Hasilnya dengan FLUENT7. Perbaiki/Rapatkan Mesh-nya dengan

FLUENT

Buat Geometri dengan GAMBIT

Geometry Command ButtonIcon untuk membuat dan modifikasi geometri

Meshing Command ButtonIcon untuk membuat dan modifikasi mesh

Zones Command ButtonIcon untuk menentukan boundary dan continuum

Tools Command ButtonIcon untuk membuat dan modifikasi sistem koordinat

Buat Geometri dengan GAMBIT

Vertex Command ButtonMembuka sub- perintah operasi pada suatu vertex (titik)

Edge Command ButtonMembuka sub-perintah operasi pada suatu edge (garis)

Face Command ButtonMembuka sub-perintah operasi pada suatu face (bidang)

Volume Command ButtonMembuka sub-perintah operasi pada suatu volume

Group Command ButtonMembuka sub-perintah operasi pada suatu group

Buat Geometri dengan GAMBITTop-Down Method

Bottom-Up Method

Vertex (Titik)

Edge (Garis)

Face (Luasan)

VolumeVolume

Vertex (Titik)

Edge (Garis)

Face (Luasan)

BENTUK GEOMETRI – 2 DIMENSIFLOW AROUND A CIRCULAR CYLINDER – 2D (MIDSPAN OF A CIRCULAR CYLINDER)

BENTUK GEOMETRI – 2 DIMENSIFLOW AROUND A CIRCULAR CYLINDER – 2D (MIDSPAN OF A CIRCULAR CYLINDER)

Mesh Geometry in GAMBIT

BENTUK MESH – 2 DIMENSIFLOW AROUND A CIRCULAR CYLINDER – 2D Face Meshing (quadrilateral map)

BENTUK MESH – 2 DIMENSIFLOW AROUND A CIRCULAR CYLINDER – 2D (MIDSPAN OF A CIRCULAR CYLINDER)

BENTUK MESH – 2 DIMENSIFLOW AROUND A CIRCULAR CYLINDER – 2D (MIDSPAN OF A CIRCULAR CYLINDER)

Set Boundary Types in GAMBIT

Set Boundary Types in GAMBIT

Setup Problem in FLUENT

Setup Problem in FLUENT

Setup Problem in FLUENT

Solve in FLUENT

Analyze Results in FLUENT

Analyze Results in FLUENT

Analyze Results in FLUENT

2D Steady Flow -Turbulence Viscous

k-epsilon Standard

Analyze Results in FLUENT

EXPERIMENTAL RESULTS NUMERICAL MODELING RESULTS –SOFTWARE FLUENT

FLOW AROUND A CIRCULAR CYLINDER – 2D (MIDSPAN OF A CIRCULAR CYLINDER)

Re = 5,4 x 104

Refine MeshRefine Mesh dengan Software FLUENT :

APLIKASI CFD

Gerakan Sudu (Impeller) padaProses Pencampuran

Aliran partikel melaluisaluran pernapasan

Commercial softwareCFD software

1. FLUENT: http://www.fluent.com2. CFDRC: http://www.cfdrc.com3. STAR-CD:http://www.cd-adapco.com4. CFX/AEA: http://www.software.aeat.com/cfx

Grid Generation software1. Gridgen: http://www.pointwise.com2. GridPro: http://www.gridpro.com

Visualization software1. Tecplot: http://www.amtec.com2. Fieldview: http://www.ilight.com