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HYDRAULICS HYDRAULICS (BFC 2073)(BFC 2073)

LECTURER: MADAM ZARINA MD. ALILECTURER: MADAM ZARINA MD. ALIROOM: D1ROOM: D1--002002

0707--4537397 / 01977223154537397 / 0197722315

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Learning ObjectivesLearning ObjectivesMengetahui pengkelasan aliran terbukadan sifat-sifat yang terkandung di dalamsesuatu bendalir.Memahami keadaan aliran di dalamsaluran terbuka.Memahami takrifan unsur-unsur geometridi dalam pengiraan aliran saluran terbuka.

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Membuat perbandingan di antara aliransaluran terbuka dan aliran di dalam paip.Mentakrif dan menghuraikan jenis-jenisaliran.Menyatakan keadaan aliran dan regimaliran.

Learning OutcomesLearning Outcomes

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SyllabusSyllabus1.1 Introduction1.2 Types of Open Channel Flow

Steady and Un-steady flowUniform and Non-uniform flow Laminar and Turbulent flow

1.3 Others

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IntroductionIntroductionHydraulic is related to the principle

of fluid mechanics usage for structure of water engineering, civil

and environmental engineering necessity especially hydraulic

structure example channel, river, weir dan water treatment plant

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Properties of FluidProperties of Fluid

Surface Tension

Viscosity

Bulk Modulus

Density

Specific Gravity

Capillarity

Compressibility

Relative Density

Properties of Fluid

IntroductionIntroduction

Quiz

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Open Channel FlowOpen Channel Flow

Flow in open channel has a free surface

which is caused by atmosphere

pressure

Atmosphere Free surface

Flow

DatumZo

dDistributed flow

IntroductionIntroduction

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Open Channel FlowOpen Channel FlowIntroductionIntroduction

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Steady FlowSteady Flow

Flow in an open-channel is considered steady if the depth of flow (y) does not change and assumed to be constant during the time interval; dy / dt = 0.

Example: Constant flow in piping flow in time

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Steady Flow (Example)Steady Flow (Example)

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Flow in an open-channel is considered unsteady if the water surface and depth of flow fluctuate from time to time. This means, dy / dt 0.

Unsteady uniform flow is an impossible condition

Example: flood

Unsteady FlowUnsteady Flow

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Uniform and NonUniform and Non--uniform Flowuniform FlowFlow is considered uniform if the depth of flow is the same at every section of the flow (dy/dx = 0). While, flow is considered non-uniform flow if the depth of flow varies at different sections of the flow (dy/dx 0).

Uniform flow Non-uniform flow

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Uniform and NonUniform and Non--uniform Flowuniform Flow1.Gradually varied flow (GVF)

the depth changes gradually over a long distance along the length of a channel.

2.Rapidly varied flow (RVF)the depth changes abruptly over a comparative short distance

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Gradually varied flow (GVF)Gradually varied flow (GVF)Example: backwater at the upstream of weir or sluice gate.

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Rapidly varied flow (RVF)Rapidly varied flow (RVF)Example: hydraulic jump

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SummarySummaryOpen Channel

Flow

Steady Flow Unsteady Flow

Uniform Flow Non-uniform FlowUniform FlowNon-uniform

Flow

GVUF

RVUF

GVF

RVF

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State of FlowState of Flow

Viscosity effect Gravity effcect

vLvL

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Reynolds number depends on viscosity

Fluid viscosity is constant

Viscosity EffectViscosity Effect

Re < 500 - laminar500 < Re < 12500 - transitionRe > 12500 - turbulent

sketch

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Laminar flow Low velocity in small

cross section channel. High viscosity.

Turbulent FlowDeep of flow. Non-prismatic cross section (i.e; river) create the turbulent flow.

Laminar and Turbulent FlowLaminar and Turbulent Flow

Transition State of flow happen when laminar flow change to turbulent flow before alter to fully turbulent.

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State as inertia force to gravity force ratio and known as Froude number,

gLvFr =

Gravity EffectGravity Effect

Where;Fr = 1 criticalFr < 1 sub criticalFr > 1 super critical

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Flow RegimeFlow Regime Combination of viscosity and gravity effect will

create 4 state of regime which are;Sub critical laminar Fr < 1.0, Re < 500Super critical laminar Fr > 1.0, Re < 500Sub critical turbulent Fr < 1.0, Re > 12500Super critical turbulent Fr > 1.0, Re > 12500

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Type of Open ChannelType of Open Channel Natural channel Artificial channel

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Type of Open ChannelType of Open ChannelEarth Channel Natural channels are waterways that exist

naturally on earth. The properties of natural channels are

normally very irregular and difficult to control. Examples: hillside rivulets, brooks, streams,

rivers and tidal estuaries.

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Type of Open ChannelType of Open ChannelArtificial Channel Artificial channels are watercourses that are

contracted and developed by human. The properties of artificial channels are based

on developers requirements and controllable. Examples: floodways, irrigation canals,

drainage ditches and spillways.

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Artificial ChannelArtificial ChannelIn engineering practice, artificial channels are given different names such as canal, flume, chute, drop, and culvert or open-flow tunnel.

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CanalCanal It is a long and mild-sloped channel built on the

ground. Exist in earth surface or coated with concrete,

cement, wood or others.

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FlumeFlume It is a hard channel or passage built from

wood, metal or concrete across a depression.

It is used in laboratory for research.

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Chute is a steep-sloped channel. Drop is similar to a chute, but the change in

elevation takes place over a very short distance.

Chute and DropChute and Drop

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It is a closed conduit and built under soil surface.

The water is in half-fully flow.

SewerageSewerage

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Geometric ElementGeometric Element

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Geometric ElementGeometric Element

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Geometric ElementGeometric Element

sketch

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Geometric Geometric ElementElement

sketch