Engineering Applications of Control Volume-1

P M V SubbaraoProfessor

Mechanical Engineering Department

True Innovations for Extrasomatism…..

First Law for A Control Volume

• Conservation of mass:

0 inoutCV mm

dt

dm

• Conservation of energy:

WQdt

dEinout

CV

Wdt

dEQ out

CVin

FVmVmdt

Vmdinout

CV

• Conservation of momentum:

Thermodynamic Domain of CVs

• Steady State Steady Flow Systems– CV, inflows and outflows are invariant.– CV is inhomogeneous.– Rate of work transfer is invariant.– Rate of heat transfer is invariant.– The Methalpy of CV is constant.

• Uniform State Uniform Flow Systems – CV is variant but homogenous.– Inflows and outflows are variant and homogeneous.– Rates of work transfer and heat transfer are variant.

First Law for CV:Steady State Steady Flow

• Conservation of mass:

00 inoutCV mm

dt

dm

• Conservation of energy:

Wdt

dEQ out

CVin

Properties of CV are Invariant:

WQdt

dEoutin

CV 0

No accumulation or depletion of mass of a CV.

No addition or removal of energy for a CV.

An Uninterrupted service for Extra-somatism!!!

Real Engineering Control Volume : SSSF

CV

out

out

in

inCV WgzV

hmgzV

hmQ

22

22

SSSF: Conservation of mass

outin mm

First Law :

CVoutoutininCV WmmQ

Development of Exotic Devices using Simple CVs

Compact Devices for carrying Weapons……

Land Based Missiles

Sea Based Missiles

Air Launched Missiles

UFO Logistics

• Is It Really Possible That The Ancient Indians Had The Capacity To Deploy Devastating Nuclear Weapons Against Their Enemies?

• Moreover, Is It Really Possible ?

• As Many Ufologists Claim, that Awesomely Powerful Nuclear Weapons Were Actually Given To The Ancient Indian Warriors By Extra-tererstrials,

• Highly Advanced Spacemen From Other Planets?

• Well, Passages From Ancient Indian National Epics Certainly Appear To Be Evidence Of Such Astonishing Claims….

• http://Www.Ufoevidence.Org/Documents/Doc1937.Htm

“The heavens cried out, the earth bellowed an answer,

lightening flashed forth, fire flamed upwards, it rained

down death. The brightness vanished, the

fire was extinguished. Everyone who was struck by the lightening was turned to

ashes”.

According To The Evidence

And again from the same source: “It was a ghastly sight to see. The corpses of the fallen were so mutilated they no longer looked like human beings. Never before have we seen such an awful weapon, and never before have we heard of such a weapon”.

The Ancient Technique : Ramjets

• Only three operating components:– intake (diffuser);– burner (combustion chamber);– nozzle.

Typical Ramjet Schematic

13

Ramjets - Basic Operating Features & Sub CVs

• Air decelerated in intake (diffuser) and pressure rises due to ram effect.

• Known as ram pressure and significant at supersonic speeds.

• A ramjet therefore needs neither a compressor nor a turbine, simplifying the design and reducing the cost.

• Greatest disadvantage is that it has to be accelerated up to typically M = 2.0 before it produces any useful thrust.

• Also complicated supersonic intake required to avoid shock losses - could be nose, side or ventral mounted.

14

Some Indian Missiles

Missile Launch Mass (t)

Propellant Range (km)

Deployed

Agni-I 12 1 stage Solid 850 1989

Agni - II 16 2.5 stage solid 3,500 2004

Agni - III 50 2 stage solid 5,500

Prithvi-I 4.4 single stage liquid

150 1988

Prithvi-II 14 Single stage liquid

250 1996

Prithvi-III 59 Single stage solid

600 2004

Ideal Thermodynamic Cycle of A Simple Missile

Sources for Microscopic Energy

Nozzles and Diffusers

outin mmMassCSSSF

: ofn onservatio:

CV

out

out

in

inCV WgzV

hmgzV

hmQ

22

22First Laws for CV in SSSF Mode:

No heat transfer : Adiabatic devices and No work transfer : rigid device.

outin

gzV

hgzV

h

22

22

Internal to external Kinetic Energy Conversion

Combined analysis of conservation of mass and first law22

22

jetjet

jetinin

in A

mh

A

mh

A SSSF of gas through variable area duct can interchange the enthalpy and kinetic energy as per above equation.

Consider gas as an ideal and calorically perfect.

jetjetp

jetpininp

inp A

m

cTc

A

m

cTc

2

1

2

1

22

jetjet

jetpinin

inp A

mTc

A

mTc

Steam Power Plant: A series of CVs in SSSF

Ideal Thermodynamic Cycle of A Simple Steam Power Plant

List of CVs

• Main components of the above cycle are:

• 1) Pump – Generate high Pressure water.

•  2) Boiler (steam generator) – heat exchanger

• 3)  Turbine – generates mechanical power

• 4)   Condenser – heat exchanger

• Others components include:

– nozzles, diffusers, throttling devices

Each one these CVs carryout a specific process continuously at almost SSSF.

However, The plant operates in a Cycle.

Pump : Adiabatic Process

CVout

outin

inCV WgzVhmgzVhmQ

22

SSSF: Conservation of mass

outin mm

First Law :

No heat transfer, change in kinetic and potential energies are negligible

outinCV gzVgzVQ

22&0

CVoutoutinin Whmhm

outlet

inlet

outinpump vdpmhhmW

In case of single inlet and exit:

CVoutoutinin Whmhm

For SSSF Process:

Liquids are incompressible, change in volume per unit change inPressure is negligible.

outin vv