- The document presents a seminar on aircraft cabin pressurization systems given by Mr. Shrinivas Kale. - It includes sections on introduction, literature review, problem formulation, objectives, methodology, hypothesis, work plan and references. - The literature review summarizes several papers on topics related to aircraft cabin pressurization, environmental control systems, and thermal comfort experiments.

1. TE SEMINARPRESENTATION
ON
“AIRCRAFT CABIN PRESSURIZATION
SYSTEM”
By
Mr.ShrinivasKale
UndertheGuidanceof
Prof.Mrs.PallaviGhogare
Department of Mechanical Engineering, PES’s MODERN COLLEGE OF ENGINEERING, PUNE

2. SUMMARY
LITERATURE
REVIEW
INTRO:FOOT
DROP
CAUSES
EXISTING
DEVICES
PROBLEM
FORMULATION SUMMARY :
• Introduction
• Literature Review
• Problem Formulation
• Objectives
• Methodology
• Hypothesis
• Work Plan
• References

3. SUMMARY
LITERATURE
REVIEW
INTRO:FOOT
DROP
CAUSES
EXISTING
DEVICES
PROBLEM
FORMULATION
INTRODUCTION :
Cabin pressurization is a process in which
conditioned air is pumped into the cabin of an
aircraft or spacecraft, in order to create a safe and
comfortable environment for passengers and crew
flying at high altitudes.
For aircraft, this air is usually bled off from the gas
turbine engines at the compressor stage, and for
spacecraft, it is carried in high-pressure,
often cryogenic tanks.
The air is cooled, humidified, and mixed with
recirculated air if necessary, before it is distributed
to the cabin by one or more environmental control
systems. The cabin pressure is regulated by the
outflow valve.

4. SUMMARY
LITERATURE
REVIEW
INTRO:FOOT
DROP
CAUSES
EXISTING
DEVICES
PROBLEM
FORMULATIO
N
Sr.
No.
Title of
Paper
Author and Year
of Publication
Summary
1 High altitude
airship cabin
sizing,
pressurization
and air
conditioning
Antonio Dumas, Diego
Angeli, Michele
Trancossi
This paper aims at defining a design
methodology for the global thermodynamic
performance of a high altitude airship cabin.
This design method applies to different
systems, which could not use the traditional
air conditioning plant layout based on bleed
air intake from the compressor stage of jet
engines.
2 Evaluation of
an improved
air distribution
system for
aircraft cabin
Liping Pang, Jie Xu,
Lei Fang, Mengmeng
Gong, Hua Zhang, Yu
Zhang
An improved air distribution system for
aircraft cabin was proposed in this paper.
Personalized outlets were introduced and
placed at the bottom of the baggage hold.
3 A novel
environmental
control system
facilitating
humidification
for
commercial
aircraft
Long Chen, Xingjuan
Zhang, Chao Wang,
Chunxin Yang
A new integrated system featuring air supply,
pressure regulation, temperature control,
water separation,
and cabin humidification is proposed based on
numerous field investigations, existing cabin
humidification
methods, and conventional aircraft
environmental control systems.
LITERATURE REVIEW :

5. SUMMARY
LITERATURE
REVIEW
INTRO:FOOT
DROP
CAUSES
EXISTING
DEVICES
PROBLEM
FORMULATIO
N
Sr.
No.
Title of
Paper
Author and
Year of
Publication
Summary
4 The
appropriate
airflow rate
for a nozzle in
commercial
aircraft cabins
based on
thermal
comfort
experiments
Xiuyuan Du,
Baizhan Li, Hong
Liu, Yuxin Wu,
Tengfei Cheng
To study the effect of the nozzle air supply on thermal
comfort and optimize the airflow rate for a nozzle, both
measurements of the air flow field and a human
thermal comfort survey were carried out in and
experimental three-row aircraft cabin. The experiments
used four airflow rates (0 L/s, 0.67 L/s, 0.96 L/s and 1.45
L/s) for a nozzle and three different cabin temperatures
(24°C, 26°C, 28°C). The air velocity distribution was
obtained to calculate the air velocity for the nozzle jets
at any point.
5 High altitude
airship cabin
sizing,
pressurization
and air
conditioning
Antonio Dumas,
Diego Angeli,
Michele
Trancossi
This paper aims at defining a design methodology for the
global thermodynamic performance of a high altitude
airship cabin. This design method applies to different
systems, which could not use the traditional air
conditioning plant layout based on bleed air intake from
the compressor stage of jet engines.
6 Evaluation of
an improved
air
distribution
system for
aircraft cabin
Liping Pang, Jie
Xu, Lei Fang,
Mengmeng Gong,
Hua Zhang, Yu
Zhang
An improved air distribution system for aircraft cabin was
proposed in this paper. Personalized outlets
were introduced and placed at the bottom of the baggage
hold. Its ratio of fresh air to recirculation air
and the conditioned temperature of different types of
inlets were also designed carefully to meet the
goals of high air quality, thermal comfort and energy
saving.

6. SUMMARY
LITERATURE
REVIEW
INTRO:FOOT
DROP
CAUSES
EXISTING
DEVICES
PROBLEM
FORMULATIO
N
PROBLEM FORMULATION

7. OBJECTIVES
METHODOLOG
Y
HYPOTHESI
S
WORKPLAN
END!
21
OBJECTIVES :
The overall purpose of
copyright law is to prevent
unfair competition by
protecting the use of a
symbol, word, logo, slogan,
design, domain name, etc.
that uniquely distinguishes
the goods or services of a
firm, Patents, Trademarks,
and Copyrights"
To do a case study on a
patented Aircraft Cabin
Pressurization System by
analysing its constructional
details and performance
parameters. Then finally
deducing its advantages
and disadvantages.

8. OBJECTIVES
METHODOLOG
Y
HYPOTHESI
S
WORKPLAN
END! METHODOLOGY :
Aim: New system required for
cabin air pressurization
Background information:
Old system are not efficient
Idea Overview:
Cabin Air Pressurization with
reference to Aircraft
Idea Overview:
Cabin Air Pressurization with
reference to Aircraft
Claims :
Developing new Aircraft Cabin
Pressurization System

9. NEED FOR CABIN PRESSURIZATION :
Pressurization becomes increasingly necessary at altitudes above
10,000 feet (3,000 m) above sea level to protect crew and
passengers from the risk of a number of physiological problems
caused by the low outside air pressure above that altitude.
For private aircraft operating in the US, crew members are
required to use oxygen masks if the cabin altitude stays above
12,500 ft for more than 30 minutes, or if the cabin altitude
reaches 14,000 ft at any time.
At altitudes above 15,000 ft, passengers are required to be
provided oxygen masks as well. On commercial aircraft, the cabin
altitude must be maintained at 8,000 feet (2,400 m) or less.
Pressurization of the cargo hold is also required to prevent
damage to pressure-sensitive goods that might leak, expand,
burst or be crushed on re-pressurization.

10. PHYSIOLOGICAL PROBLEMS ARISING DUE
TO FAILURE OF CABIN PRESSURIZATION:
 Hypoxia : The lower partial pressure of oxygen at altitude reduces
the alveolar oxygen tension in the lungs and subsequently in the brain,
leading to sluggish thinking, dimmed vision, loss of consciousness, and
ultimately death.
 Altitude sickness :Hyperventilation, the body's most common response to
hypoxia, does help to partially restore the partial pressure of oxygen in the
blood, but it also causes carbon dioxide (CO2) to out-gas, raising the blood
pH and inducing alkalosis.
 Decompression sickness : The low partial pressure of gases, principally
nitrogen (N2) but including all other gases, may cause dissolved gases in
the bloodstream to precipitate out, resulting in gas embolism, or bubbles
in the bloodstream.
 Barotrauma : As the aircraft climbs or descends, passengers may
experience discomfort or acute pain as gases trapped within their bodies
expand or contract.

11. BASIC SYSTEM OPERATION :
 Pressurization is achieved by the design of an airtight fuselage
engineered to be pressurized with a source of compressed air and
controlled by an environmental control system (ECS). The most common
source of compressed air for pressurization is bleed air extracted from
the compressor stage of a gas turbine engine, from a low or
intermediate stage and also from an additional high stage; the exact
stage can vary depending on engine type.
 By the time the cold outside air has reached the bleed air valves, it is at
a very high pressure and has been heated to around 200 °C (392 °F). The
control and selection of high or low bleed sources is fully automatic and
is governed by the needs of various pneumatic systems at various stages
of flight.
 The part of the bleed air that is directed to the ECS is then expanded to
bring it to cabin pressure, which cools it. A final, suitable temperature is
then achieved by adding back heat from the hot compressed air via
a heat exchanger and air cycle machine known as the packs system.
 In some larger airliners, hot trim air can be added downstream of air
conditioned air coming from the packs if it is needed to warm a section
of the cabin that is colder than others.

12.  At least two engines provide compressed bleed air for all the plane's
pneumatic systems, to provide full redundancy. Compressed air is also
obtained from the auxiliary power unit (APU), if fitted, in the event of an
emergency and for cabin air supply on the ground before the main engines are
started. Most modern commercial aircraft today have fully redundant,
duplicated electronic controllers for maintaining pressurization along with a
manual back-up control system.
 All exhaust air is dumped to atmosphere via an outflow valve, usually at the
rear of the fuselage. This valve controls the cabin pressure and also acts as a
safety relief valve, in addition to other safety relief valves. If the automatic
pressure controllers fail, the pilot can manually control the cabin pressure
valve, according to the backup emergency procedure checklist.
 The automatic controller normally maintains the proper cabin pressure
altitude by constantly adjusting the outflow valve position so that the cabin
altitude is as low as practical without exceeding the maximum pressure
differential limit on the fuselage. The pressure differential varies between
aircraft types, typical values are between 7.8 psi (54 kPa) and
9.4 psi (65 kPa). At 39,000 feet (12,000 m), the cabin pressure would be
automatically maintained at about 6,900 feet (2,100 m) (450 feet (140 m)
lower than Mexico City), which is about 11.5 psi (79 kPa) of atmosphere
pressure.

13. SCHEMATIC DIAGRAM :

14. NEW CABIN PRESSURIZATION SYSTEM :
 A system for controlling cabin pressurization in an aircraft cabin, comprising:
 First means for providing a cabin altitude signal indicative of the air pressure in said
aircraft cabin.
 Second means for providing a cabin altitude rate change signal indicative of the
actual rate of change of air pressure in said aircraft cabin.
 Third means for providing an aircraft altitude signal indicative of the ambient air
pressure on the exterior of the aircraft, and hence the altitude of the aircraft;
 Auto schedule means for calculating a commanded rate of change of air pressure in
said aircraft cabin in response to aircraft altitude.
 Means for controlling the air pressure in said aircraft cabin in response to said cabin
altitude signal and said commanded rate of change.
 Clamp control means for maintaining a constant pressure situation in said aircraft
cabin, said constant pressure situation being initiated when the change of said
aircraft altitude signal over a preset time period is less than a first predetermined
value, said constant pressure situation being maintained until said aircraft altitude
signal changes by a second predetermined value from the value of said aircraft
altitude signal at the time said constant pressure situation was initiated.

15. ADVANTAGES :
This System helps to maintain Aircraft cabin pressure at high
altitude with great precision and accuracy.
It respond to minor changes in cabin pressure with respect to
aircraft altitude.
It generates ambient atmosphere for passengers and prevents
passengers from physiological problems.
It also maintains and monitor cabin air quality as per directed
by WHO.

16. CONCLUSION :
The Conclusion of this case study is that the Aircraft
Pressurization System is very much precise and
accurate.
Aircraft Pressurization System is easy to handle and it
must be regularly and precisely maintained by well
trained engineers.

17. APPENDIX :

18. Future Scope

19. REFERENCES
1
2
3
4
5
6
7
8
9
10

20. OBJECTIVES
METHODOLOGY
HYPOTHESI
S
WORKPLAN
END!
THANK YOU