Design of air circuit disinfection against COVID-19 in the conditions of airliners

The impact of the COVID-19 pandemic on tourists' air travel intentions: The role of perceived health risk and trust in the airline

Travel restrictions as well as travellers' increased risk perceptions have changed travel patterns around the globe during the COVID-19 pandemic. As such, the aviation industry has been particularly affected by the changing environment. Several airlines have reacted to travellers' rising concerns about becoming infected with the COVID-19 disease by introducing safety measures to guarantee a safe journey. Although research has noted the relevance of good communication during crises, the impact of communicating safety measures by rational (safety) advertising appeals on air travel intention has not been explored thus far. The current study investigates consumers' reactions to two different types of advertising appeals during the COVID-19 pandemic and their effect on air travel intentions and airline recommendation intentions. An online experiment reveals that travellers react more positively to safety as compared to emotional advertising appeals during the COVID-19 pandemic. Furthermore, the results confirm the hypothesized mediating effect of perceived health risk and trust in the airline on the impact of safety appeals in terms of air travel intention and airline recommendation. The results of this study uncover the underlying mechanisms that have driven consumers' air travel intentions during the COVID-19 pandemic and offer various theoretical and managerial implications.

Exploring the potential of electrostatic precipitation as an alternative particulate matter filtration system in aircraft cabins

On most modern airliners, cabin air pressurization, heating, and renewal are mainly achieved using air supplied from the gas turbine engines during flight. This air intake impairs the motors yield and needs to be conditioned, leading to energy overconsumption. Recent advances in thermal management enable aircraft manufacturers to reduce further the intake airflow needed to maintain cabin temperature at high altitude. Nevertheless, for lower air renewal rates, an appropriate air filtration system will be needed to maintain acceptable air quality in the cabin. In this context, Clean Sky 2 Joint Undertaking (CS2JU) project EC2S (Environment Control Secondary System) aims at developing an integrated filtration system to be implemented in existing cabin air management systems (so-called environmental control system-ECS). The EC2S unit will include three filtration units addressing separately volatile organic compounds (VOCs), CO₂ , and particulate matter (PM). Circulated air in the ECS is conventionally filtered on pleated HEPA filters that generate substantial pressure drop. Since the EC2S VOCs and CO₂ filtration units would generate additional pressure drop in the ECS system, electrostatic precipitation is foreseen as a low flow resistance alternative for PM removal. This paper reports the development and performance assessment of a two-stage electrostatic precipitator (ESP) designed for aircraft recirculated air filtration. The ESP prototype presents high single-pass particle collection rates (i.e., over 90% for airborne particles with an aerodynamic diameter of 0.5 μm or larger), low-pressure drop (i.e., 4 Pa at nominal flowrate), and a limited ozone generation rate (i.e., below 8 mg h^-1 ).

A critical review of heating, ventilation, and air conditioning (HVAC) systems within the context of a global SARS-CoV-2 epidemic

The Coronavirus disease (COVID-19) has spread over the world, resulting in more than 225 million patients, and 4.7 million deaths in September 2021. It also caused panic and terror, halted numerous activities, and resulted in the world economy deteriorates. It altered human behavior and compelled people to alter their lifestyles to avoid infection. Air conditioning systems are one of the most important sectors that must be considered because of the pandemic SARS-CoV-2 all over the world. Air is used as a heat transfer medium in heating, ventilation, and air conditioning (HVAC) systems. The air contains a variety of pollutants, viruses, and bacteria, all of which have an impact on and destroy human life. Significantly in summer, people spend more time in air conditioners which results in lower levels of vitamin D and melatonin which may affect the functioning of their immune system and are susceptible to receiving SARS-CoV-2 from other individuals. As an important component of air conditioning and ventilation systems, the air filter plays a significant role. As a result, researchers must work harder to improve its design to prevent the ultra-small particles loaded with COVID-19. This paper contributes to the design of existing HVAC systems in terms of their suitability and impact on the spread of the hybrid SARS-CoV-2 epidemic, as well as efforts to obtain a highly efficient air filter to remove super-sized particles for protection against epidemic infection. In addition, important guideline recommendations have been extracted to limit the spread of the SARS-CoV-2 throughout the world and to get the highest quality indoor air in air-conditioned places.

Towards Promising Platform by Using Annular Photonic Crystals to Simulate and Design Useful Mask

Human masks are considered the mainstay in air filtration and purification technologies and against the spreading of bacterial and viral infections. This paper introduces a novel design of a human mask to increase the ultraviolet germicidal irradiation effect on pathogens. The proposed design consists of a tube with an annular photonic crystal (APC) attached to the mask’s orifice, and a UV source is located in the tube’s center. The main role of this study is the enhancement of UV doses based on the reflectivity of the proposed APC. Therefore, increasing pathogens’ inactivation level in the incoming air to the mask’s orifice could be investigated. The numerical investigations demonstrated that the proposed APC could provide a complete photonic bandgap with a high reflectivity in the wavelength regime from 207 to 230 nm. In addition, we have considered the roles of the thickness of layers, inner core radius, and the azimuthal number. Meanwhile, the results showed the ability to use a wide range of core radius values without almost any variations in the optical properties of the proposed design. Such results could grant the advantage of using this design by the manufacturing of human masks with different sizes besides the inclusions in other ultraviolet germicidal irradiation applications.