1. ch1 intro & classification of turbomachines

Fluid Machineries

Chap I: by: Hasan Basri Introduction and Calssification of Turbo Machines

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CHAPTER 1

INTRODUCTION AND CLASSIFICATION OF TURBOMACHINES 1.1. DEFINITION OF TURBOMACHINES

Fluid handling devices that direct the flow with blades or vanes attached to a rotating member are termed turbomachines. FOX

All those devices in which energy is transferred to a fluid or work is done by extracting energy from a fluid through rotating the axis of a machine. Shirani

The transfer of energy between a continuous stream of fluid and an element rotating about a fixed axis. Turton

All those devices in which energy is transferred either to, or from, a continuously flowing fluid by the dynamic action of one or more moving blade rows. Dixon

Relevant Unit

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1.2. INTRODUCTION AND CLASSIFICATION OF FLUID MACHINES Positive Displacement:

Energy transfer by volume changes

Fluid is confined completely

Dynamic (Turbomachines)

Radial-Flow (Centrifugal)

Axial-Flow

Mixed-Flow

Machines for Doing Work on a Fluid

Positive-Displacement Pumps

Pumps

Fans (small pressure rise < 25 mm.water)

Blowers (moderate pressure rise = 25 mm.Hg)

Compressors (high pressure rise up to 1 GPa (104 atm)

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Energy added to fluid

(i.e. work done on the fluid)

Energy used as means

Energy transfer

Energy subtracted from fluid

(i.e. work done by the fluid)

Hydraulic Coupling

Torque converter

Hydraulic ram

Jack press

Pumps, fans, compressor

Uncased Cased

Propellers and

Screws

Mixed flow

Centrifugal

axial

Rotodynamic

Machines

Turbines

Reaction Impulse

Axial Flow

(Kaplan)

Pelton Wheel

windmills Mixed Flow

(Francis)

Radial flow

(banki or early Francis

Motor

Gear Vane Piston

Pumps and compressor

Rotary Reciprocating Positive Displacement

Machines

Swashplate

Crank driven

Direct Driven

Miscellaneous

Lobe

Vane

Gear

Screw

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Fans, Blowers, and Compressors

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Vaned Diffuser

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Volute/Scroll

Machines for Extracting Work (Power) from a Fluid

Hydraulic Turbines (Impulse and Reaction)

Gas Turbines (Impulse and Reaction)

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1.3. TURBOMACHINERY ANALYSIS

The Angular Momentum Principle

Apply to Control Volume:

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Euler Turbomachine Equation

Prewhirl or Prerotation

Mechanical Power:

Theoretical Head:

EULER EQUATION

Torque T = m (C 2r2 C 1r1)

Power P = T = m (U2C 2 U1C 1)

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Slip Factor

Velocity Diagrams

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Energy Transfer Components

Kinetic Energy or Dynamic Head

Centrifugal Energy

Relative velocity Energy

Dynamic Pressure Difference Static Pressure Difference

Reaction Degree (R=0 => Impulse turbomachine)

Example: Idealized Centrifugal Pump

Negligible torque due to surface forces (viscous and pressure).

Inlet and exit flow tangent to blades.

Uniform flow at inlet and exit.

Zero inlet tangential velocity

Head Equation:

Shutoff Head:

g

VV

g

UU

g

VVH rr

222

2

1

2

2

2

2

2

1

2

2

2

1

g

VV

g

UU

g

VVH rr

222

2

1

2

2

2

2

2

1

2

2

2

1

H

gVVUUR rr

2/212

2

2

2

2

1

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Hydraulic Power:

Pump Efficiency:

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1.4. PERFORMANCE CHARACTERISTICS


Fans, Blowers, and Compressors

Hydraulic Power:

Turbine Efficiency:

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Example

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Problems :

1). 2).

3).

4).

5).

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References

1. Turbomachines (2nd Ed). E. Shirani

2. Principles of Turbomachinery (2nd Ed). R.K. Turton

3. Turbomachinery, Basic Theory and Applications (2nd Ed). E. Logan

4. Thermodynamics of Turbomachinery (3rd Ed). S.L. Dixon

5. Introduction to Fluid Mechanics (5th Ed). R.B. Fox & A.T. McDonald

6. Any Turbomachinery books.

1. ch1 intro & classification of turbomachines

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