1. 1 Copyright © 2016 by ASME
Proceedings of the ASME 2016 International Mechanical Engineering Congress and Exposition
IMECE2016
November 11-17, 2016, Phoenix, Arizona, USA
IMECE2016-65341
EXPERIMENTAL INVESTIGATION OF VENTILATION EFFECTIVENESS IN AN
AIRLINER CABIN MOCKUP
Jignesh A Patel
Kansas State University
Manhattan, Kansas, USA
Byron W Jones
Kansas State University
Manhattan, Kansas, USA
Mohammad H Hosni
Kansas State University
Manhattan, Kansas, USA
Ali Keshavarz
Kansas State University
Manhattan, Kansas, USA
ABSTRACT
Frequent air travel and long flight duration makes the study
of airliner cabin environmental quality a topic of utmost
importance. Ventilation effectiveness is one of the more crucial
factors affecting air quality in any environment. Ventilation
effectiveness, along with the overall ventilation rate, is a measure
of the ability of the air distribution system to remove internally
generated pollutants or contaminants from a given space.
Because of the high occupant density in an aircraft cabin, local
variations in ventilation are important as a passenger will occupy
the same space for the duration of the flight. Poor ventilation in
even a small portion of the cabin could impact multiple people
for extended time periods. In this study, the local effective
ventilation rates and local ventilation effectiveness in an eleven-
row, full-scale, Boeing 767 cabin mockup were measured. These
measurements were completed at each of the 77 seats in the
mockup. Each seat was occupied by a heated mannequin. In
order to simulate the thermal load inside the cabin, the
mannequins were wrapped with a heating wire to generate
approximately 100 W (341 BTU/hour) of heat. Carbon dioxide
was used as a tracer gas for the experiments and the tracer gas
decay method was employed to calculate the local effective
ventilation rate and local ventilation effectiveness. The overall
ventilation rate, based on total supply air flow, was
approximately 27 air changes per hour. Local ventilation
effectiveness ranged from 0.86 to 1.02 with a mean value of 0.94.
These ventilation effectiveness values are higher than typically
found in other indoor applications and are likely due to the
relatively high airspeeds present in the aircraft cabin and the high
degree of mixing they provide. The uniformity is also good with
no areas of particularly low ventilation effectiveness being
identified. No clear patterns with respect to seat location,
window versus center versus aisle, were found.
NOMENCLATURE
C CO2 concentration
E ventilation effectiveness
e local effective ventilation rate
t time
V volume
𝑄̇ volumetric airflow rate
( )cabin cabin
( )e at exhaust/outlet
( )i equilibrated
( )local at particular seat location
( )p at measuring points
( )inlet at inlet
INTRODUCTION
Based on 2015 US-Based Airline Traffic Data released by
U.S Department of Transportation [1], the number of passengers
travelling through commercial airliners both domestically and
internationally has significantly increased over the years. Thus
the health effects caused by the air quality inside the cabin is of
increasing concern. For example transmission of disease may
occur as a result of an infected person sneezing or coughing
putting the health of other passengers at risk. Other sources of
risk to health can be air contamination due to irritants, heat
buildup, oil contaminants from the engine bleed air, malicious

2. 2 Copyright © 2016 by ASME
intents or unclean supply air. The environment control system
(ECS) in an aircraft is responsible for providing a healthy and
comfortable cabin environment. The ECS maintains the required
cabin pressure and temperature and maintains contaminant levels
inside the cabin within acceptable limits via ventilation. The
ECS is required to remove contaminants like dust, odor and
smoke to maintain the air quality inside the cabin. In order to
ensure the proper removal of these contaminants and further
improvement of the ECS a detailed study of the ventilation
effectiveness was conducted.
This study of ventilation effectiveness can be carried out in
two ways, either experimentally or numerically using
computational fluid dynamics (CFD). Many experimental and
numerical studies have been done previously to determine
airflow inside a cabin. Lin et al. [2] developed a numerical tool
using CFD to study the airflow pattern inside a B767-300
passenger cabin. Their study demonstrates the difficulties
associated with the numerical method of analyzing the airflow
inside an aircraft cabin. Sun Y et al. [3, 4] performed experiments
to study the effects of supply air temperature, cold fuselage wall,
and passenger occupancy and passenger thermal plume on the
airflow inside an aircraft cabin. They found that for isothermal
(supply air temperature same as cabin temperature) and non-
isothermal conditions the air velocities at the passenger
breathing level were identical. Their study also concluded that
the obstructions of seats and passenger occupancy had a
significant effect on the airflow in the cabin and that a cold
fuselage wall caused an increase in the air velocities at the
window seats. Zhang et al. [5] compared the experimental and
CFD simulation results for the airflow pattern, temperature field
and contaminant dispersion and distribution. They used tracer
gas (sulfur hexafluoride) to mimic gaseous contaminants and 0.7
µm di-ethyl-hexafluoride particles to imitate particulate
contaminants. For their airflow patterns they noticed two large
circulations in the lateral direction which were asymmetrical.
Their experimental and CFD simulations agreed qualitatively but
quantitatively the two methods were not consistent, also the
temperature profiles had a better agreement than the velocity
profiles. They concluded that the two methods agreed reasonably
for the velocity field, temperature field, particulate and tracer gas
concentration. Due to the highly turbulent and unstable airflow
inside the cabin, the high thermal load, obstructions like high
passenger occupancy and complex cabin geometry, accurate
computer modelling is a very difficult task. Therefore an
experimental approach was used in the present study.
It is important to understand that the velocity profile inside
an aircraft cabin alone is not sufficient information to determine
the efficient removal of contaminants. For example higher
velocity at a certain region may not necessarily imply better
removal of contaminants as the contaminants maybe recirculated
rather than being eliminated. Thus, local effective ventilation
rates and ventilation effectiveness are key parameter which can
be used to predict the efficiency of the ventilation system. Wang
et al. [6] carried out an experimental study of ventilation
effectiveness and air velocity distribution inside a Boeing 767-
300 mockup cabin having 35 seats. They used the volumetric
particle tracking velocimetry technique to determine the velocity
profile in the cabin. To study ventilation effectiveness they used
the tracer gas technique and evaluated the local mean age of air
using Eq. (1).
Local Mean Age of Air =
∫ Ci(t)dt
∞
0
Ci(0)
(1)
They calculated the ventilation effectiveness factor using Eq. (2).
Ventilation Effectiveness Factor =
Ce− Cinlet
Cp− Cinlet
(2)
They evaluated the local mean age of air and ventilation
effectiveness factor for three rows inside the cabin. They found
that the local mean age of air ranged from approximately 2
minutes to 6 minutes and the ventilation effectiveness factor
ranged from approximately 1 to 1.4. These values are higher than
the ventilation effectiveness evaluated in the study done for this
paper (E ranged from 0.86 to 1.02). They also studied the effects
of air supply rate on the ventilation effectiveness. From their
study they concluded that the flow inside the cabin was highly
lateral, also the local mean age of air was dependent on the
velocity magnitude and the airflow pattern in that region and that
the ventilation effectiveness had a linear relationship with the air
supply rate.
Singh et al. [7] concluded that occupancy of the cabin affects
the airflow patterns inside the cabin from their numerical study
of airflow in an aircraft cabin section. Thus, for the study
reported in this paper, in order to create a typical airliner cabin
condition all the seats of the cabins were occupied by heated
mannequins.
The main objective of the research reported in this paper is to
experimentally evaluate the local effective ventilation rates and
the ventilation effectiveness at typical airliner cabin conditions
inside a full-scale Boeing-767 mockup cabin. The tracer gas
decay method was employed to calculate the local effective
ventilation rates and the ventilation effectiveness for the entire
cabin. Local effective ventilation rate was evaluated by injecting
CO2 as the tracer gas into the cabin supply air.
EXPERIMENTAL APPARATUS
Experiments were conducted in the Aircraft Cabin
Environment Research Laboratory at the Kansas State
University. A mockup cabin of a Boeing 767 aircraft was used to
carry out the experiments. The cabin has a 2-3-2 seat
configuration and a total of seventy-seven seats (eleven rows and
seven seats per row). The seats are labeled A to G from left to
right and the rows of seats are numbered 1 to 11 from front to
back. As shown in Fig. 1 all the seats were occupied by plastic
mannequins wrapped with 25 m (82 feet) of heater wire to
generated 102 W (348 BTU/hour) of heat to account for the
sensible heat generated by an average resting human body (70W
i.e. 239 BTU/hour) and various other sources like laptops,
phones, in-flight entertainment systems etc. There are hallways

3. 3 Copyright © 2016 by ASME
on each side of the cabin which contain the tracer gas sampling
equipment and data acquisition (DAQ) equipment. There are two
exhaust fans at the front face of the enclosure which maintain the
cabin enclosure at approximately neutral pressure.
Figure 1. Boeing 767 mockup cabin with manikins wrapped
with heater wire occupying all the seats.
According to the FAA [8], the acceptable humidity and
temperature ranges for the cabin are 25 to 70 percent relative
humidity and 18.3 °C (65 °F) to 26.7 °C (80 °F) respectively.
FAA regulations also require a minimum ventilation rate of 0.25
kg/min (0.55 lbm/min) of fresh air for each passenger which,
according to ASHRAE [9] is equivalent to 0.212 m3
/min (7.5
cfm) at sea level or 0.283 m3
/min (10 cfm) at an approximately
244 m (8000 feet) cabin altitude and typical cabin temperatures.
Most modern aircraft supply approximately 0.57 m3
/min (20
cfm) per passenger to the cabin with approximately one-half of
that amount being filtered recirculated air and approximately
one-half being outside air. In order to recreate the conditions
inside an actual airliner cabin in the cabin mockup, the air supply
systems was designed to supply 40 m3
/min (1400 cfm) i.e.
approximately 0.515 m3
/min (18.18 cfm) per seat of air at
15.6 °C (60 °F). The air supply diffusers were from a Boeing 767
aircraft and were installed in the same arrangement as in an
actual aircraft. The main components of the air supply system
were a blower, dehumidifier, hot-water heater, water chiller and
an electric heater. Figure 2 shows the detailed diagram of the air
supply system used.
The blower pulled outside air at approximately 40 m3
/min
(1400 cfm) and passed it through the dehumidifier which
reduced the relative humidity of the outside air to the range of 12
to 15 percent. The water chiller and water heater were used as
needed to bring the supply air to approximately 10 °C (50 °F).
The electric heater then provided fine control to deliver air to the
cabin at 15.6 °C (60 °F).
Figure 2. Diagram of the air supply system [10].
This study was conducted using industrial CO2 as the tracer.
Previous researchers observed that good mixing was difficult to
achieve by injecting tracer gas at point locations in the cabin. In
order to ensure thorough mixing of the tracer gas within the cabin
air, CO2 was injected into the cabin air supply duct well
upstream of the cabin supply diffusers to ensure thorough mixing
prior to entering the cabin and the air with the added CO2 was
supplied to the cabin for a period of time long enough for the
concentration in the cabin to become uniform. The CO2 flow rate
was precisely metered through a mass flow controller. The CO2
supply was then turned off while the ventilation continued and
the CO2 concentration in the cabin allowed to decay.
Figure 3. Tracer gas sampling system.
Tracer gas was sampled at various seats using four infrared
CO2 analyzers located inside the cabin. In order to avoid moving
the analyzers to various seats and to simplify the sampling
procedure, sampling ports were used. As can be seen from Fig. 3
each sampling port consisted of a 7.92 m (26 feet) long vinyl
tube, one end of the vinyl tube was connected to the sampling

4. 4 Copyright © 2016 by ASME
line of the analyzer and the other end was mounted on a wooden
support. The sampling port was then moved to various seats to
sample the tracer gas at that location. A vacuum pump
downstream of the analyzer was used to pull air through the
sampling line into the analyzers.
Two computers running different data acquisition programs
were used to control the cabin air supply system and the tracer
gas system. All the data from various sensors were collected by
data acquisition interfaces and communicated to the two
computers.
TESTING PROCEDURE
Four sets of experiments were performed. The first set of
experiments evaluated the local effective ventilation rates. The
second set checked for the effect of the sampling lines on the
transient response of the measuring system. The third set
checked for the effect of the CO2 analyzer on the transient
response of the measuring system. The fourth set checked the
experiment repeatability.
The air supply system was allowed to run for 20 minutes
before starting experiments to achieve steady state. Each
experiment began by allowing the cabin to stabilize for 10
minutes with no entry of researchers so as to avoid recording any
disturbances caused by movement in the cabin. CO2 was then
supplied for 12 minutes at an injection rate of 15 liters per minute
(0.53 cfm) to the cabin by injecting it directly into the cabin
supply air in order to ensure thorough mixing. The CO2 injection
was continued until the cabin reached steady state CO2
concentration. The CO2 injection was then stopped while the
ventilation continued and the experiment was allowed to run for
another 15 minutes to get transient data for CO2 concentration
decay inside the cabin.
For the first set of experiments, all seats inside the cabin were
assessed in a number of experiments. Since only four CO2
analyzers were available, the experiments were repeated
multiple times and the sampling ports moved from seat to seat to
cover all the seats inside the cabin. The first experiment began
by placing the sampling ports at seats B, D and F of the 1st
row
and then following with the same seats in row 2 to 11 in order.
After seats B, D and F were evaluated for all rows, seats A, C, E
and G were analyzed following the same procedure. The
sampling ports were constructed and positioned in a way so that
the sampling would occur at the breathing level of an occupant
i.e. 0.24 m (0.787 feet) in front of and level with the headrest.
The tracer gas decay method was employed to calculate the
local effective ventilation rates and the ventilation effectiveness
of the entire cabin. The local effective ventilation rate was
calculated by measuring the time-dependent CO2 concentration
corrected for the CO2 concentration in the outside air. A mass
balance of tracer gas was applied to the cabin to give the
following equation for the local effective ventilation rate,
e = (Q̇ /V)local =
(
dC 𝑝
dt
)
C 𝑝−Cinlet
(3)
The ventilation effectiveness was then evaluated using the
following mathematical equation,
E =
(Q̇ /V)local
(Q̇ /V)cabin
(4)
Data were collected for all the seventy seven seats of the cabin
and the experiments were conducted three times at each seat to
confirm the repeatability of the results.
As the transient decay of CO2 was used to evaluate the
ventilation effectiveness it was important to study the time
response of the measuring system. Since sampling ports were
connect to the analyzers with tubes approximately 7.92 m (26
feet), it was also important to check if time delays due to the
length of the tubes had any effect on the calculated ventilation
rates. The second set of experiments was conducted to perform
this check. Four seats were selected according to convenience for
the placement of the analyzers. Experiments were then
performed with analyzers placed at those seats with a shorter
(approximately 0.36 m i.e. 14 inches) tube and without tubes,
local effective ventilation rates readings from these experiments
were then compared with results from experiments where 7.92
m (26 feet) long tubes were used. The third set of experiments
was performed to evaluate the time response of the analyzers.
The experiments began by placing three of the four sampling
ports of the analyzers outside the cabin, the fourth sampling port
was kept inside the cabin to check the CO2 concentration inside
the cabin. The cabin was allowed to reach steady state CO2
concentration, the sampling ports were then inserted inside the
cabin through the side ventilation grills to generate a well-
defined step input to the sensor. The time taken by the analyzers
to record the change in CO2 concentration gave the time
response of the analyzers. The experiments were repeated three
times by varying the sampling port which was kept inside the
cabin to ensure that all the four analyzers were assessed. Another
important check performed was the repeatability of the
experiments. The fourth set of experiments was performed to
fulfill this requirement. For this set of experiments, ports of the
four analyzers were placed at particular common convenient
locations. With the locations fixed, six consecutive experiments
were performed and the data from each of these cases were
compared to check for repeatability.
RESULTS AND DISCUSSIONS
Ventilation effectiveness evaluation
The local effective ventilation rates were evaluated using the
tracer gas decay method and Eq. (3). It was essential to estimate
the optimal time period during the decay for which the data
would be analyzed. Shown in Fig. 4 is a plot of local effective
ventilation rates versus time for a typical experiment. As can be
seen from Fig.4 the value of effective ventilation rate is a bit off
during the initial two minutes. This offset may be due to time
required to flush the supply ducts. From 2 minutes to 7 minutes,
the value remains more or less constant. It becomes erratic after

5. 5 Copyright © 2016 by ASME
about 7 minutes as most of the injected CO2 is flushed out,
causing both the denominator and numerator values in Eq. (3) to
tend to zero. All the seat locations were plotted to assess the
optimal time period and it was concluded that the time period 2
minutes to 6 minutes would be most appropriate to analyze the
data.
Figure 4. Typical plot of local effective ventilation rate versus
time for three seats.
Table 1 summarizes the average result for the three
measurements of local effective ventilation rates at all the
seventy-seven seat locations. It can be seen from Tab.1 that the
variation in the local effective ventilation rate throughout the
cabin is not very large, with the maximum value of 0.46/min at
seat 4D and the minimum value of 0.39/min at seat 10C and a
mean value of 0.42/min. The standard deviation of all the values
is 0.0143/min. Figure 5 shows the variation in local effective
ventilation rates at all the seat locations inside the mockup cabin.
The results show that the local effective ventilation rate is fairly
uniform throughout the cabin.
Table 1. Result for local effective ventilation rates (min-1
) for
the entire cabin.
Row Seat A B C D E F G
1 0.41 0.43 0.43 0.42 0.43 0.44 0.45
2 0.45 0.42 0.44 0.43 0.45 0.44 0.43
3 0.43 0.44 0.42 0.44 0.42 0.45 0.40
4 0.43 0.45 0.43 0.46 0.44 0.43 0.42
5 0.40 0.42 0.42 0.44 0.42 0.44 0.42
6 0.42 0.41 0.41 0.44 0.42 0.41 0.41
7 0.42 0.42 0.41 0.43 0.44 0.42 0.43
8 0.41 0.41 0.40 0.40 0.42 0.42 0.40
9 0.42 0.42 0.41 0.44 0.40 0.43 0.43
10 0.41 0.40 0.39 0.42 0.41 0.43 0.43
11 0.43 0.40 0.41 0.40 0.43 0.41 0.42
Figure 5. Variation of local effective ventilation rates with
different seat locations.
In order to calculate the ventilation effectiveness, the volume
of the cabin needed to be calculated. The volume of the cabin
was evaluated numerically using the mathematical equations for
the cabin profile given by Shehadi [11]. To verify the result,
volume was also evaluated in a spreadsheet utilizing the cabin
profile data. Results from both the methods were consistent with
each other and gave the cabin volume to be approximately 91 m3
(3210 cubic feet). This value was reduced to 87.8 m3
(3100 cubic
feet) to account for the volume occupied by the seats and heated
mannequins. Table 2 presents the result for the local ventilation
effectiveness for the entire cabin.
Table 2. Result for ventilation effectiveness for the entire
cabin.
Row Seat A B C D E F G
1 0.92 0.95 0.95 0.93 0.94 0.98 0.99
2 0.99 0.93 0.98 0.96 0.99 0.97 0.95
3 0.95 0.97 0.94 0.98 0.93 0.99 0.89
4 0.96 0.99 0.95 1.02 0.97 0.95 0.93
5 0.89 0.93 0.93 0.97 0.94 0.98 0.93
6 0.93 0.91 0.91 0.97 0.93 0.90 0.90
7 0.93 0.93 0.91 0.96 0.98 0.94 0.96
8 0.92 0.91 0.89 0.89 0.93 0.94 0.88
9 0.92 0.93 0.90 0.97 0.90 0.95 0.94
10 0.90 0.89 0.86 0.92 0.92 0.95 0.94
11 0.96 0.90 0.92 0.88 0.95 0.91 0.92
As the ratio of the ventilation supply rate to the volume of the
cabin applies to the whole cabin, the local ventilation
effectiveness is proportional to the local effective ventilation rate
as indicated by the numbers in Tab. 2. For perfect mixing, the
value of ventilation effectiveness is unity. As we can see from
Tab. 2 ventilation effectiveness is more or less uniform
throughout the cabin with a maximum value of 1.02 at seat 4D
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
LocalEffectiveVentilationRates(min-1)
Time(mins)
1
2
3
4
5
6
7
8
9
10
11
0.30
0.40
0.50
A B C D E F G
Rows
LocalEffectiveVentilationRates(min-1)
Seats
1 2 3 4 5 6 7 8 9 10 11

6. 6 Copyright © 2016 by ASME
and minimum value of 0.86 at seat 10C. The mean value is 0.94
and the standard deviation for the entire cabin is 0.0316.
Figure 6. Variation of local ventilation effectiveness with
different seat locations.
Figure 6 shows that the values for ventilation effectiveness for
all the seats are high and reasonably consistent throughout the
cabin. Therefore, it can be concluded that the air is uniformly and
efficiently ventilated for all the seats inside the cabin, at least for
this particular mockup.
Effect of transient response on readings
Two experiments were performed to study the effect of the
sampling tube length. One experiment used a 0.36 m (14 inch)
tube connecting each of the analyzers and another experiment
was conducted without any tubes. For convenience, the seats 5B,
4D, 3A and 4C were selected and the analyzers were placed at
these locations as mentioned in Tab. 3.
Table 3. Measured Local ventilation rates (min-1
) with
varying sample tube length.
Seat Location 5B 4D 3A 4C
Test Analyzer 1 2 3 4
With Short Tubes 0.40 0.40 0.40 0.41
Without Tubes 0.42 0.42 0.44 0.42
With 26 feet Tubes 0.42 0.45 0.43 0.43
Table 3 shows the results for experiments with short tubes
and no tubes and compares those results with the results with
7.92 m (26 feet) long vinyl tubes for the same seats. It can be
seen from Tab. 3 that the values of local effective ventilation
rates for each of the three cases shows only slight variation and,
if anything, the results with the longer sample tubes yielded the
highest ventilation rates, which was unexpected. Thus, it can be
safely concluded that the sampling tube length did not interfere
with accurate measurement of the tracer gas decay transient.
Time response of analyzers
Table 4 gives the details and results for the experiments
conducted to examine the time response of each analyzer. The
time listed for each analyzer is the time required for it to record
steady state CO2 concentration after it was subjected to a step
change in concentration at the inlet to the sampling tube. As can
be seen from the table, analyzer 3 was quickest to respond to the
change in CO2 concentration with a time response of
approximately 10-12 seconds, while the other three analyzers
had the same time response of approximately 15 seconds. These
time response are very short compared to the 10-15 minutes
transient associated with the CO2 decay in the cabin and thus,
instrument time response was eliminated as source of
measurement error.
Table 4. Result for time response (seconds) of sampling
system.
Test Analyzer 1 2 3 4
1 15 15 In cabin 15
2 In cabin 15 10 15
3 14 In cabin 12 14
Experiment repeatability
Table 5 gives the details and results for the experiments
conducted to check for the repeatability of the experiments. Six
consecutive experiments were performed one right after the
other on the same day to carry out this study. For convenience
the analyzers were placed at seat locations 9D, 8D, 6D and 7D
as mentioned in the Tab. 5.
Table 5. Result for tests on experiment repeatability (min-1
).
Seats 6D 7D 8D 9D
Test Analyzer 1 2 3 4
1 0.44 0.46 0.43 0.41
2 0.41 0.41 0.40 0.40
3 0.44 0.42 0.45 0.43
4 0.42 0.41 0.43 0.38
5 0.43 0.41 0.41 0.45
6 0.43 0.43 0.40 0.42
Standard Deviation 0.0117 0.0197 0.0200 0.0243
It can be seen from the results that the variations in the values
for all the four analyzers is small but not insignificant. The mean
of the standard deviations of the four locations is 0.019/min as
compared to a standard deviation of 0.0143/min for the variation
from seat to seat for the data in Tab. 1. Thus, experimental
repeatability is likely an important factor in the seat-to-seat
variation. However, the data in Tab. 1 represent the average of
three replications at each seat. Correcting the 0.019/min value
for three replications gives a standard deviation of 0.0134/min
which is essentially the same as the seat to seat variation standard
1
2
3
4
5
6
7
8
9
10
11
0.70
0.80
0.90
1.00
1.10
A B C D E F G
Rows
VentilationEffectiveness
Seats
1 2 3 4 5 6 7 8 9 10 11

7. 7 Copyright © 2016 by ASME
deviation in Tab. 1. The first two replications for the Tab. 1 data
were taken consecutively over a few days, while there was a time
gap of approximately six months between the first two and the
third replications. The placement of a particular analyzer
corresponding to a particular seat location remained the same for
the first two sets while it was varied during the third set of
experiments. The mean value of the local ventilation rates for the
first two experiments was 0.427/min and the mean value for the
third experiments was 0.421/min indicating consistent results
over the extended time period. The variations from the mean for
each seat were compared between the experimental replications
and those variations were found to be uncorrelated.
Consequently, the seat-to-seat variations seen are likely due to
experimental variations and not due to spatial variation in the
local ventilation. Given the good uniformity seen throughout the
cabin, the result is not particularly surprising.
CONCLUSIONS
In this study, we experimentally evaluated the local effective
ventilation rates and the ventilation effectiveness of a full-scale
aircraft cabin mockup. It was concluded that the time period
from 2 minutes to 6 minutes during the tracer gas decay was the
optimal time period for data analysis. It was observed that local
effective ventilation rates was fairly uniform throughout the
cabin with the maximum value being 0.46/minute at seat 4D and
the minimum value being 0.39/minute at seat 10C. The mean
values was 0.42/minute and the standard deviation for the values
was 0.0143/min. Most of this variation is likely due to
experimental variation. It can thus be concluded that the local
ventilation is uniform throughout the cabin within the limits of
the measurement repeatability. The ventilation effectiveness
value depends on the local effective ventilation rates and hence
had identical variations. The ventilation effectiveness varied
from a maximum value of 1.02 at seat 4D to a minimum value
of 0.86 at seat 10C. The mean value was 0.94 and the standard
deviation for the entire cabin was 0.0316. It can be concluded
from the results found in this study that, as desired, air is
effectively supplied to all seat locations inside the cabin mockup.
This study did not take into consideration the effects of
gaspers on the ventilation effectiveness and no gaspers were
opened for any of the experiments. Therefore investigating the
effects of gaspers on the ventilation effectiveness is another
topic, which should be investigated further.
ACKNOWLEDGMENTS
This research was partially funded by the U.S. Federal
Aviation Administration (FAA) Office of Aerospace Medicine
through the National Air Transportation Center of Excellence for
Research in the Intermodal Transport Environment under
Cooperative Agreement 07-C-RITE-KSU. Although the FAA
has sponsored this project, it neither endorses nor rejects the
findings of this research. Presentation of this information is in
the interest of invoking technical community comment on the
results and conclusions of the research.
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