# Presentation: 193732

## Slide 1

## ...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

## 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**

## Cyclic 

**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**_

## First Solution for Cabin Air Distribution - Outlet

- Inlet
- Boundary Condition

- Pressure
- Boundary Condition

- Honeycomb Slice Detail

## First Solution for Cabin Air Distribution - Outlet  cont’d

_**First Solution for Cabin Air Distribution - Outlet**_**  cont’d**

## First Solution for Cabin Air Distribution - Flow Pattern Analysis

**ECS in heating and cooling operations**

_**First Solution for Cabin Air Distribution - Flow Pattern Analysis**_

## First Solution for Cabin Air Distribution - Flow Pattern Results

- _Section at the ECS Outlet_

_**First Solution for Cabin Air Distribution - Flow Pattern Results**_

## First Solution for Cabin Air Distribution - Flow Pattern Results  cont’d

- _Middle Section between two ECS Outlets_

_**First Solution for Cabin Air Distribution - Flow Pattern Results**_**  cont’d**

## First Solution Analysis Results

- 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**_

## Final Solution for Cabin Air Distribution - Outlet

- Inlet
- Boundary Condition

- Pressure
- Boundary Condition

- Honeycomb Slice Detail

_**Final Solution for Cabin Air Distribution - Outlet**_

## Final Solution for Cabin Air Distribution - Outlet cont’d

_**Final Solution for Cabin Air Distribution - Outlet**_** cont’d**

## Final Solution for Cabin Air Distribution - Flow Pattern Results

- _Section at the ECS Outlet_

_**Final Solution for Cabin Air Distribution - Flow Pattern Results**_

## Final Solution for Cabin Air Distribution - Flow Pattern Results  cont’d

- _Middle Section between two ECS Outlets_

_**Final Solution for Cabin Air Distribution - Flow Pattern Results**_**  cont’d**

## Analysis Results and Design Progress

- 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**_

## 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

**ECS Outlet Exit Measurement Grid**

## Numerical and Experimental Results Comparison

## 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_

## Ground Smoke Tests Results

- Cargo Main Deck - Normal Operation - 25 SCFM - Left Side

## Ground Smoke Tests Results

- Cargo Main Deck - Normal Operation - 32.5 SCFM - Central Zone

## Ground Smoke Tests Results

- Cargo Main Deck - Failure Case - 25 SCFM - Right Side

## Slide 22

## 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