engineering applications of control volume-1 p m v subbarao professor mechanical engineering...
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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
Sea Based 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
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
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
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