The Airline/PAX Configuration
As shown in the Article #2, the Airline/PAX Configuration of the Numeric Corporate Jet considers an entire Main Cabin (Vol#1), Toilet (Vol#3) and Cockpit (Vol#100) in the Main Deck. The Cabinet to be analysed as the closed-compartment (Vol#2) is installed inside the Main Cabin (Vol#1).
Vol#01 is a large 5‘813ft³ volume.
Closed Compartment Vol#02 is simulated with several sizes: 5, 10, 15, 20, 25, 50, 75, 100, 125, 150 ft³. For each one of this volume, several gaps are simulated from 0in² to 70in².
Results for PAX configuration
[SPOILER ALERT!] For those who are in a hurry, here are the results obtained with ESonix V3 for the PAX configuration.
The Table below summarizes the results obtained by ESonix software after a run considering all parameters and data described here under.
As shown in this Table and previously explained, combinations between several Cabinet Volumes and Cabinet Vent were considered in the analysis. The pressure sustained for each combination is here presented in psi.
The table is formatted as in Boeing D655441 document, i.e. closed-compartment volume as horizontal entry and closed-compartment venting area as vertical entry. Differential pressures are rounded up to 2 digits.
For example, A 75ft³ closed-compartment with a 4in² gap would experience a 2.92 psi relative pressure!
As expected, the 0in² gap leads to maximum differential pressure whatever the Cabinet volume. Also, the greater the volume and the smaller the gap, the higher the differential pressure. For small volumes and big gaps (lower-left corner of the table),differential pressures are low enough to be rounded to 0.
NOTE: As the Numeric Corporate Jet has been designed for training purpose only, the results of this Table doesn’t correspond to any existing commercial aircraft. In a real case scenario, the generation of this Table is made possible with ESonix using TWEAKS parameters and BATCH mode analysis. Additional information about TWEAKS parameters and BATCH mode is available in the ESonix Manuals (see Manuals). Moreover, ESonix Tutorials provides a good opportunity to practice the use of those features (see Tutorials).
The Vent/Volume ratio curve
A convenient way to display this table is to show the differential pressure as a function of the vent/volume ratio (Airbus is using this representation).
But showing the vent/volume axis with a logarithmic scale is even more convenient:
The next step will be to calculate the same curves for the VIP configuration, where the aircraft volume in which the Cabinet is enclosed will be reduced from 5813ft³ to 653ft³. This is shown in Article #4.
Configuration Details
Download the ESonix numeric Corporate Jet in its pax configuration.
The following sections show how the volumes, their connections and the load case referring to this configuration are defined for the Esonix software.
Volumes
The table below reproduces the Esonix sheet Volumes.
id label deck sta rbl volume
[in] [in] [ft³]
1 Main Cabin 0 15500 0 10044550.4
2 Cabinet 0 7100 100 *variable*
3 Lavatory 0 6200 100 164764.8
20 Cargo E. Bay -1 7000 0 1220480
21 FWD Cargo Bay -1 11500 0 915360
22 Over Wing -1 17000 0 274608
23 AFT Cargo Bay -1 23000 0 1708672
24 Bulk Bay -1 28500 0 225788.8
30 FWD Ceiling 2 7500 0 48819.2
31 Mid Ceiling 1 2 12500 0 140355.2
32 Mid Ceiling 2 2 21000 0 128150.4
33 AFT Ceiling 2 26500 0 97638.4
100 Cockpit 0 4000 0 488192
The Ceiling is divided in 4 volumes (Vol#30, Vol#31, Vol#32, Vol#33) which are connected to the Main Deck. The Cargo Deck is divided in 5 volumes (Vol#20, Vol#21, Vol#22, Vol#23, Vol#24) which are also connected to the Main Deck.
Cabinet Volume and its Connection
Although defined in the Esonix sheets Volume and Connections, the parameters (volume and vent area) of the Cabinet to be analysed as the closed-compartment (Vol#2), are modified by Esonix feature called Tweaks. Through this feature (Tweaks) the Cabinet Volume varied from 5 in³ to 150 in³ and the Cabinet Vent Area varied from 0 in² to 70 in².
NOTE: The user can check the Tutorial #6 of Esonix manual for additional information about the Tweaks feature of Esonix software.
Load Case
The Airline/PAX Configuration analysis assumes an opening hole on the Main Cabin (Vol#01), where the Cabinet (Vol#02) is installed. The initial pressure differential between the cabin and the ambient is 8.6psi.
Connections
Four types of connection between aircraft volumes are considered in the Airline/PAX Configuration. They are:
Active Vents
The following figure illustrates the active vents (B01, B02, B03, B04, B05, B08, B09, B10, B11 and B12) considered in the Airline Configuration.
The following table shows how these active vents are considered by Esonix on its sheet Connections.
id vol_i vol_j comments vent_area open._pres cp vent_area open._pres cp
i_to_j i_to_j i_to_j j_to_i j_to_i j_to_i
[in²] [psi] [-] [in²] [psi] [-]
51 1 31 Ceiling Blowout panel B01 0 0 0 387.50 0.217 0.6
52 1 31 Ceiling Blowout panel B02 0 0 0 1162.50 0.217 0.6
53 1 32 Ceiling Blowout panel B03 0 0 0 1162.50 0.217 0.6
54 1 32 Ceiling Blowout panel B04 0 0 0 1271.00 0.217 0.6
55 1 33 Ceiling Blowout panel B05 0 0 0 1271.00 0.217 0.6
58 1 23 Floor Blowout panel B08 310.00 0.435 0.6 0 0 0
59 1 23 Floor Blowout panel B09 310.00 0.435 0.6 0 0 0
60 1 24 Floor Blowout panel B10 310.00 0.435 0.6 0 0 0
61 20 21 Cargo Blowout panel B11 434.00 0.507 0.6 697.50 0.435 0.6
62 23 24 Cargo Blowout panel B12 465.00 0.435 0.6 620.00 0.507 0.6
Passive vents
The following figure illustrates the passive vents (V01, V02, V03, V04, V05, V06, V07, V08, V11, V12, V13, V14, V15, V16, V17, V18, V19, V20, V21), considered in the Airline Configuration.
The passive vent between Cabinet and Main Cabin is also defined here, although this connections is variable as explained below.
The following table shows how these passive vents are considered by Esonix on its sheet Connections.
id vol_i vol_j comments vent_area cp
i_to_j i_to_j
[in²] [-]
1 1 2 Cabinet to Main Cabin *variable* 0.60
11 1 30 Passive Vent V01 15.5 0.45
12 1 30 Passive Vent V02 15.5 0.45
13 1 30 Passive Vent V03 15.5 0.45
14 1 30 Passive Vent V04 77.5 0.45
15 1 31 Passive Vent V05 15.5 0.45
16 1 31 Passive Vent V06 31.0 0.45
17 1 32 Passive Vent V07 46.5 0.45
18 1 33 Passive Vent V08 46.5 0.45
21 1 33 Passive Vent V11 46.5 0.45
22 1 33 Passive Vent V12 46.5 0.45
23 1 33 Passive Vent V13 77.5 0.45
24 30 31 Passive Vent V14 46.5 0.45
25 31 32 Passive Vent V15 108.5 0.45
26 32 33 Passive Vent V16 31.0 0.45
27 20 100 Passive Vent V17 542.5 0.45
28 20 21 Passive Vent V18 310.0 0.45
29 21 22 Passive Vent V19 310.0 0.45
30 22 23 Passive Vent V20 310.0 0.45
31 23 24 Passive Vent V21 232.5 0.45
Door Vents
The following figure illustrates the doors considered in Airline Configuration: Cockpit Door (D01) and Toilet Door (D02).
The following table shows how the doors and its vents are considered by Esonix on its sheet Connections.
The Cockpit Door (D01) is equipped with two blowout panels, see ids #2 and #3 in the table.
id vol_i vol_j comments door vent_area open._pres cp vent_area open._pres cp
i_to_j i_to_j i_to_j j_to_i j_to_i j_to_i
[in²] [in²] [psi] [-] [in²] [psi] [-]
2 1 100 Cockpit door, Blowout 01 0 325.5 0.58 0.6 0 0 0
3 1 100 Cockpit door, Blowout 02 0 480.5 0.58 0.6 0 0 0
4 1 3 Lavatory swivel door D02 2480 2480.0 0.29 0.6 2480 0.29 0.6
Side Vents
The following table shows the Side Vents considered in the Esonix table Connections. Side Vents are passive vents between the Main Deck and the Cargo Deck.
id vol_i vol_j comments vent_area cp
i_to_j i_to_j
[in²] [-]
32 1 20 RHS Vent 37.2 0.45
33 1 20 RHS Vent 55.8 0.45
34 1 21 RHS Vent 10.1 0.45
35 1 21 RHS Vent 70.5 0.45
36 1 21 RHS Vent 23.3 0.45
37 1 22 RHS Vent 182.1 0.45
38 1 22 RHS Vent 40.7 0.45
39 1 23 RHS Vent 187.2 0.45
40 1 23 RHS Vent 49.6 0.45
41 1 24 RHS Vent 6.2 0.45
42 1 20 LHS Vent 77.5 0.45
43 1 20 LHS Vent 55.8 0.45
44 1 21 LHS Vent 119.4 0.45
45 1 21 LHS Vent 15.5 0.45
46 1 22 LHS Vent 182.1 0.45
47 1 22 LHS Vent 40.7 0.45
48 1 23 LHS Vent 187.2 0.45
49 1 23 LHS Vent 49.6 0.45
50 1 24 LHS Vent 6.2 0.45
NEXT STEP…
The next Article will show the details and results of the Small Volume Decompression analysis considering the Numeric Corporate Jet in the VIP Configuration.
See here the list of Articles referring to the study of Small Volume Decompression:
-
Article #1: Small Volumes Decompression #1 - Understanding the Problem
-
Article #2: Small Volumes Decompression #2 - Airline/Pax, VIP configurations and Aircraft Parameters
-
Article #3: Small Volumes Decompression #3 - Analysis of closed compartment in the Cabin Airline/PAX Configuration
-
Article #4: Small Volumes Decompression #4 - Analysis of closed compartment in the Cabin VIP Configuration
-
Article #5: Small Volumes Decompression #5 - Airline X VIP Results Comparison
-
Article #6: Small Volumes Decompression #6 - Airline X VIP Results Comparison (Further Step)
-
Article #7: Small Volumes Decompression #7 - Decompression Analysis considering the Cabinet Stiffness
-
Article #8: Small Volumes Decompression #8 - Study summary and conclusions