**4.1 Simulation steps in CFD**

The air quality and its impact on humans during the cruise are determined by the aeronautical comfort design and have strong influences on the thermal conditions of the passenger. The air recirculation used before the airborne pathologies by various types of viruses. For example, according to researches presented during the Roomvent Congress, 2014, ventilation is related to the circulation of contaminants in airplanes cabins which from expiratory activities, cause cross-contamination events. Belonging to the list of studies about environmental comfort this research therefore, evaluates the actual thermal behavior of the airplane commercial user. In the face of the need to investigate air diffusers, responsible for the crew discomfort and for the transmission of diseases such as the so-called SARS (Severe Acute Respiratory Syndrome), and the challenges that are imposed on the intentions to design a healthy and comfortable environment in the cabins, we analyze the air distribution in the interior project of such cabins. The research focuses around the armchair and duct shapes with the use of the Computational Fluid Dynamic (CFD) tool.

The results of this chapter present a model based on computation that can predict the temperature and airflow as well as the parameters of environmental air distribution in commercial airplanes cabins, in empty cabins, and with passengers seated or standing. The model is known as CFD (Computational Fluid-Dynamic Model). The purpose of this item is to present to the reader some of the main fundamentals that are necessary for the applications of CFD related to internal environmental technology in commercial aircrafts.

This item presents the information used in the data entry for the CFD commercial airplane e-170 cabin simulation: **Figure 9**.

**Figure 9.** *Mesh refinement.*

**Figure 10.** *Shows the air breathed by passengers.*

## **4.2 Results**

The results of this chapter present a model based on computation parameters that the air distribution and environment temperature in the commercial aircraft cabin are the passengers breathing, empty cabin, and with the passenger seated or standing. The

purpose of this item is to present to the reader some of the main fundamentals that are necessary for the applications of CFD related to the internal environmental technology for commercial aircrafts.

## **4.3 Passengers breathing**

The passangers breathing inside the plane's cabin is presented in **Figure 10**.

#### **4.4 Empty cabin**

The representation of the empty cabin with the representation of the air supply diffuser going from the top part to the bottom one with the cabin height of 0–1.70 m and 0–1.50 m length is presented in **Figure 11**. **Figure 12** identifies the magnitude velocity from 0 to 0.9 m/min noticing that the maximum airspeed is concentrated close to the gasper outlet, decreasing its speed throughout the path to the air outlet at the bottom of the cabin. The air temperature in degree Celsius is presented in **Figure 13**, ranging from 22°C to 28°C, notice that this temperature is used for tropical climate inhabitants, different from the countries located in Scandinavia, where temperature above 18°C is the upper limit in summer. The air supply diffuser using a computational mesh through the cabin is shown in **Figure 14**. **Figures 15** and **16** demonstrate, as an example, the points of a constant air temperature value and speed for an empty cabin.

#### **4.5 Front view of the cabin with the standing manikin**

The airspeed with the passenger standing is represented in **Figure 17** with a variation of magnitude velocity from 0 to 0.11 m/s. **Figure 18** presents the air surface

**Figure 12.** *Airspeed in the empty cabin.*

**Figure 13.** *Air temperature in the empty cabin.*

**Figure 14.** *Air supply diffuser representation using a computational mesh.*

**Figure 15.** *Iso surface are surfaces that represent points of a constant number. For example, temperature and airspeed.*

**Figure 16.** *Iso surface are surfaces that represent points of a constant number. For example, temperature and airspeed.*

and **Figure 19** identifies the air temperature between 24.88 and 27.04°C. Demonstrated in **Figure 20** is the image from the perspective of the cabin. The cabin refining mesh is presented in **Figure 21**.

**Figure 17.** *Airspeed with passenger standing.*

**Figure 18.** *Iso surface of the cabin with passenger standing.*

**Figure 20.** *Iso surface of the airflow line with passenger standing.*

**Figure 21.** *Cabins mesh refinement with passenger standing.*
