INTRODUCTIONINTRODUCTION

REFERENSIREFERENSI

1. C.J. GEANKOPLIS : “TRANSPORT PROCESSES AND UNIT OPERATIONS”, EDISI 3, PRENTICE HALL INTERNATIONAL, 1995

2. N. de NEVERS : “FLUID MECHANICS FOR CHEMICAL ENGINEERS”, EDISI 2, McGRAW HILL INTERNATIONAL,1991

3. R.S. BRODKEY & H.C. HERSHEY: “TRANSPORT PHENOMENA, A UNIFIED APPROACH”, INTERNATIONAL EDITION, McGRAW HILL, 1989

4. J.M. WELTY, C.E. WICKS & R.E. WILSON: “FUNDAMENTAL OF MOMENTUM, HEAT, AND MASS TRANSFER”, EDISI 4, JOHN WILEY & SONS, 2001

MOMENTUM MOMENTUM TRANSFER orTRANSFER orFLUID FLUID MECHANICSMECHANICS

Sir Isaac Newton1642-1727

MECHANICS AND GRAVITATIONMECHANICS AND GRAVITATION According to the well-known story, it was on seeing an apple fall in his orchard at

some time during 1665 or 1666 that Newton conceived that the same force governed the motion of the Moon and the apple. He calculated the force needed to hold the

Moon in its orbit, as compared with the force pulling an object to the ground. He also calculated the centripetal force needed to hold a stone in a sling, and the relation

between the length of a pendulum and the time of its swing. These early explorations were not soon exploited by Newton, though he studied astronomy and the problems of

planetary motion.Correspondence with Hooke (1679-1680) redirected Newton to the problem of the path

of a body subjected to a centrally directed force that varies as the inverse square of the distance; he determined it to be an ellipse, so informing Edmond Halley in August 1684. Halley's interest led Newton to demonstrate the relationship afresh, to compose

a brief tract on mechanics, and finally to write the Principia.Book IBook I of the Principia states the foundations of the science of mechanics, developing

upon them the mathematics of orbital motion round centres of force. Newton identified gravitation as the fundamental force controlling the motions of the celestial bodies. He never found its cause. To contemporaries who found the idea of attractions across empty space unintelligible, he conceded that they might prove to be caused by

the impacts of unseen particles.Book IIBook II inaugurates the theory of fluids: Newton solves problems of fluids in

movement and of motion through fluids. From the density of air he calculated the speed of sound waves.

Book IIIBook III shows the law of gravitation at work in the universe: Newton demonstrates it from the revolutions of the six known planets, including the Earth, and their satellites.

However, he could never quite perfect the difficult theory of the Moon's motion. Comets were shown to obey the same law; in later editions, Newton added conjectures on the possibility of their return. He calculated the relative masses of heavenly bodies

from their gravitational forces, and the oblateness of Earth and Jupiter, already observed. He explained tidal ebb and flow and the precession of the equinoxes from

the forces exerted by the Sun and Moon. All this was done by exact computation.Newton's work in mechanics was accepted at once in Britain, and universally after half a century. Since then it has been ranked among humanity's greatest achievements in abstract thought. It was extended and perfected by others, notably Pierre Simon de

Laplace, without changing its basis and it survived into the late 19th century before it began to show signs of failing. See Quantum Theory; Relativity.

TRANSPORT TRANSPORT PHENOMENA ?PHENOMENA ?

• TRANSPORT PHENOMENA = FENOMENA PERPINDAHAN = PERISTIWA PERPINDAHAN

• TRANSPORT PHENOMENA MELIBATKAN 3 (TIGA) PROSES PERPINDAHAN :•PERPINDAHAN MASSA•PERPINDAHAN PANAS•PERPINDAHAN MOMENTUM

• PROSES PERPINDAHANNYA SERING TERJADI SECARA SIMULTAN DENGAN ANALOGI SAMA

MEKANISME TRANSFERMEKANISME TRANSFER

• MEKANISME TRANSFER

MOLEKULER (MTM)

• MEKANISME TRANSFER

TURBULENSI (MTB)

MEKANISME TRANSFER PANAS MEKANISME TRANSFER PANAS MOLEKULERMOLEKULER

HEAT FLOW

HEAT TRANSFER

FIRE

ResistanceforceDriving

Rate

BENTUK ANALOGI

HK FOURIER

dz

Tcd

Aq pz

Fluks panas J/s.m2

Difusivitas

panas, m2/s

Kons. panas J/m3

MEKANISME TRANSFER MASSA MEKANISME TRANSFER MASSA MOLEKULERMOLEKULER

N2 O2

MASS TRANSFER HUKUM

FICK

dzdc

DJ AABAz

*

ResistanceforceDriving

Rate

BENTUK ANALOGI

Fluks massa

A mol/s.m

2

Difusivitas molekul A

dlm B, m2/s

Kons. massa

A mol/m3

MEKANISME TRANSFER MEKANISME TRANSFER MOMENTUM MOLEKULERMOMENTUM MOLEKULER

MOMENTUM TRANSFER

LAMINAR FLOW

HK NEWTON VISKOSITAS

ResistanceforceDriving

Rate

BENTUK ANALOGI

dzvd x

zx

Fluks mom arah z akibat komponen kecepatan x (kg.m/s)/s.m2

Difusivitas momentum,

/m2/s

Arah perpindaha

n momentum

x

z

MOMENTUM TRANSFER ?MOMENTUM TRANSFER ?

MOMENTUM TRANSFER = MOMENTUM TRANSFER = FLUID FLUID MECHANICSMECHANICS

MOMENTUM TRANSFER : MOMENTUM TRANSFER :

THE STUDY OF FORCE AND MOTION THE STUDY OF FORCE AND MOTION OF FLUIDSOF FLUIDS

PENTINGNYAPENTINGNYA MEKANIKA MEKANIKA FLUIDAFLUIDA? ? (1)(1)

• PROCESS INDUSTRIES: PROCESS INDUSTRIES: BEBERAPA MATERIAL ADALAH DALAM BENTUK FLUIDA DAN HARUS DISIMPAN, DIHANDLING, DIPOMPA..

• HYDRAULICS: HYDRAULICS: PIPE FLOW, PUMPS, TURBINES

• PARTICLE DYNAMICS : PARTICLE DYNAMICS : FLOW AROUND PARTICLE, INTERACTION OF PARTICLES AND FLUIDS (SETTLING, SLURRIES, PNEUMATIC TRANSPORT, FLUIDIZED BED, AIR POLLUTANT PARTICLE)

• MULTIPHASE FLOW: MULTIPHASE FLOW: COMBUSTION, SPRAYS, FLOW IN REACTOR, DISTILATION COULOMN

PENTINGNYA MEKANIKA PENTINGNYA MEKANIKA FLUIDA?FLUIDA? (2)(2)

• METEREOLOGY:METEREOLOGY: FLOW OF THE ATMOSPHERE

• HYDROLOGY:HYDROLOGY: FLOW WATER IN THE GROUND

• VISCOUS FLOWS :VISCOUS FLOWS : LUBRICATION, INJECTION MOLDING, EKSTRUKSI POLIMER, DLL

IDE DASAR IDE DASAR dalamdalam MEKANIKA MEKANIKA FLUIDA FLUIDA (1)(1)

• 4 PRINCIPLES:4 PRINCIPLES:• CONSERVATION OF MASS• CONSERVATION OF ENERGY= FIRST LAW OF

THERMO• SECOND NEWTON’S LAW=SECOND LAW

THERMO• NEWTON’S LAW OF MOTION

• SIMPLE FLOWS : SIMPLE FLOWS : BILA 4 PRINSIP DASAR TERSEBUT DAN SIFAT FISIK TERUKUR DAPAT DISELESAIKAN LANGSUNG SECARA MATEMATIKA GAYA, KECEPATAN, DLL

• COMPLEK FLOWS :COMPLEK FLOWS : BILA 4 PRINSIP TERSEBUT HANYA DAPAT DISELESAIKAN DENGAN EKSPERIMEN, ANALISIS DIMENSI & SIMULASI CFD

EXAMPLE OF COMPLEX FLOWS EXAMPLE OF COMPLEX FLOWS ARROUND A SUBMERGED ARROUND A SUBMERGED

OBJECTOBJECT

EXAMPLE OF COMPLEX FLOWS EXAMPLE OF COMPLEX FLOWS IN STIRRED TANK ANALYZED IN STIRRED TANK ANALYZED

BY CFDBY CFD

Fluid velocity vector

Velocity Vectors Colored By Velocity Magnitude (m/s)FLUENT 5.0 (3d, segregated, ke)

Jan 19, 2000

2.50e+00

2.29e+00

2.08e+00

1.87e+00

1.66e+00

1.46e+00

1.25e+00

1.04e+00

8.35e-01

6.27e-01

4.19e-01

2.12e-01

4.17e-03

Z

Y

X

Solid concentration contour

0,047

0,019

0,03

0,035

0,041

0,046

0,063

0,057

0,046 0,052

0,052

0,0680,081

0,181

0,201

0,201

0,221

0,181

0,281

0,241

0,161

0,08

Cav = 5% Cav = 20%

Local gas hold up at several position from baffle

00 10 450

EXAMPLE OF COMPLEX FLOWS EXAMPLE OF COMPLEX FLOWS IN COMBUSTION ANALYZED BY IN COMBUSTION ANALYZED BY

CFDCFD

Vektor Kecepatan dalam Ruang Bakar

Distribusi Suhu dalam Ruang Bakar

Distribusi Suhu dalam Ruang Bakar

Distribusi CO2 dalam Ruang Bakar

(a)

Distribusi O2 dalam Ruang Bakar