1. Mr. D. Cannoletta - Environmental Control System Department Mr. E. Riegel - Environmental Control System Department ENVIRONMENTAL CONTROL SYSTEM CABIN AIR DISTRIBUTION SIMULATION CARGO AIR FLOW PATTERN FOR SMOKE DETECTION FAA INTERNATIONAL AIRCRAFT SYSTEMS FIRE PROTECTION WORKING GROUP Atlantic City, November 5 th - 6 th 2003

2. CARGO AIR FLOW PATTERN FOR SMOKE DETECTION …background  ECS cabin air distribution design for multi-mission aircraft  Air pattern definition is a key factor for ECS design goals  Passengers aircraft and cargo aircraft design objectives usually different (comfort for passengers and prompt smoke detection for cargo configuration)  CFD approach  Tool complexity balanced by powerful investigation capabilities  Technical risks reduction and shorten development phase

3. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION Presentation Summary  ECS Cabin Air Distribution Model  Model Creation  Model Development  CFD analysis and improvements identification  Optimization process through iterative loop  CAD-CFD FEM interaction  Model Validation  Design evolution  Full scale aircraft fuselage compartment ground smoke tests campaign  Test results and conclusions

4. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION  ECS cabin air distribution optimization for passengers comfort and smoke detection  3D model analyzed by a finite elements method CFD code  Domain extension and computational workload taken into account:  Only a fuselage half section represented  Entire extension obtained through cyclic and symmetrical boundary conditions Cyclic Boundary Condition Symmetric Boundary Condition Model Creation and Development

5. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION First Solution for Cabin Air Distribution - Outlet Inlet Boundary Condition Pressure Boundary Condition Honeycomb Slice Detail

6. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION First Solution for Cabin Air Distribution - Outlet cont’d

7. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION  Cruise at 5000 ft cabin altitude  ECS in heating and cooling operations Symmetric Boundary Condition Inlet Boundary Condition Cyclic Boundary Condition Pressure Boundary Condition First Solution for Cabin Air Distribution - Flow Pattern Analysis

8. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION Heating Operation (Tf = 167°F, OAT=-67°F) Section at the ECS Outlet First Solution for Cabin Air Distribution - Flow Pattern Results

9. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION Heating Operation (Tf = 167°F, OAT=-67°F) Middle Section between two ECS Outlets First Solution for Cabin Air Distribution - Flow Pattern Results cont’d

10. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION Shortfalls identified  High air velocity in the cabin and flow pattern jeopardizing smoke detection  Passengers comfort penalties Corrective action  New design of the ECS outlet, changing the orientation on the surface fuselage First Solution Analysis Results

11. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION Inlet Boundary Condition Pressure Boundary Condition Honeycomb Slice Detail Final Solution for Cabin Air Distribution - Outlet

12. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION Final Solution for Cabin Air Distribution - Outlet cont’d

13. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION Heating Operation (Tf = 167°F, OAT=-67°F) Section at the ECS Outlet Final Solution for Cabin Air Distribution - Flow Pattern Results

14. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION Heating Operation (Tf = 167°F, OAT=-67°F) Middle Section between two ECS Outlets Final Solution for Cabin Air Distribution - Flow Pattern Results cont’d

15. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION  Air distribution and temperature uniformity with low air velocity in the cabin leading to passenger comfort and smoke detection benefits  the flow pattern in the cabin helps the smoke to rise up to the fuselage ceiling where the smoke detectors are installed  Most suitable zone for the smoke detectors installation identified  the section between two ECS outlets  on the ceiling just after the wall  Analysis results application  CFD Model Validation  Solution embodied into design Analysis Results and Design Progress

16. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION CFD Model Validation Test  CFD model validated by test laboratories  Measurement, through an anemometer, of the air velocity in different points along two different stations  Dedicated CFD model created to simulate the test condition and measurement pattern 23 in” 4.92” 1.23 in” MID C B A A’ B’ C ‘ Diffuser ECS Outlet Exit O z x y ECS Outlet Exit Measurement Grid

17. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION Numerical and Experimental Results Comparison

18. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION Ground Smoke Tests  Ground smoke tests campaign  Compartment full scale mock-up with draw-thru smoke detectors and approved smoke generator  ECS outlets and outlets grids detail level reproduced  11 test points along the compartment  Different flow conditions in normal operation and failure cases Test Rig Scheme Test Rig Detail Level

19. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION Ground Smoke Tests Results Cargo Main Deck - Normal Operation - 25 SCFM - Left Side

20. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION Ground Smoke Tests Results Cargo Main Deck - Normal Operation - 32.5 SCFM - Central Zone

21. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION Ground Smoke Tests Results Cargo Main Deck - Failure Case - 25 SCFM - Right Side

22. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION

23. Atlantic City, November 5 th - 6 th 2003 CARGO AIR FLOW PATTERN FOR SMOKE DETECTION Conclusions CFD analysis benefits along the design process  Flow pattern simulation compliant with the test results in all the normal operation and failure conditions  Correct identification of the most suitable zone for smoke detectors installation  Flexible investigation on wide spectrum of solutions  Reduction of the smoke detection time  Reduction of the technical risk associated to the development and certification tests