Numerical investigation of air stability in space capsule under low gravity conditions

Wang, Yadi; Gong, Gwo‐Ching; Xu, Cheng; Yang, Zhouzhou

doi:10.1016/j.actaastro.2014.06.040

Cited by 11 publications

(3 citation statements)

References 15 publications

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“…A −6° HDBR experiment is regarded as the most effective terrestrial simulator of weightlessness in space medicine research, 20 although some researchers have also used Computational Fluid Dynamics (CFD) simulation methods to simulate the air flow in weightless environments. 21,22 During a −6° HDBR experiment in an environmental chamber, body fluids could be displaced from the lower body to the upper body in the first seven days. Thereafter, vascular remodelling and adaptive changes in neural functions would take place, and the human cardiovascular system would start to function in response to real weightlessness.…”

Section: Methodsmentioning

confidence: 99%

Effects of simulated weightlessness on thermal sweating of human body: An experimental study

Zhu

Wang

Yu³

et al. 2018

Indoor and Built Environment

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Thermal sweating is the thermoregulatory activity of the human body in hot and warm environments, which is critical to the human thermal comfort and health. The sweating of a human body in a real weightlessness environment has seldom been researched, and simulated weightlessness has usually been conducted under comfortable environments. In order to study the sweating of the human body under weightlessness, a 7-day −6° head down bed rest experiment was carried out on six male subjects lying on their backs to simulate the physiological changes that occur under a weightless environment. The skin microcurrents of the subjects were recorded to evaluate sweating under a range of environments. The results showed that sweating was more significant in the torso and head areas than on the arms and lower body. The whole body sweat rates of subjects were lower than those before the simulated weightlessness experiment. However, the threshold air temperature for the onset of sweating under simulated weightlessness was higher than that before the simulation. This was possibly due to the raising of thermoregulatory set-point temperature of the body. Findings have shown that the sweating behaviour and thermal response of a male human body in a weightless environment could be different to those in the terrestrial condition.

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Section: Methodsmentioning

confidence: 99%

Effects of simulated weightlessness on thermal sweating of human body: An experimental study

Zhu

Wang

Yu³

et al. 2018

Indoor and Built Environment

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“…In recent years, limited space air stability has gained attention (Gong et al, 2010 ; Wang et al, 2014 ; Xu et al, 2015 ; Deng and Gong, 2019). According to Gong et al (2010) , the air condition in limited spaces can be divided into stable, neutral and unstable by the vertical distribution of temperature in the limited spaces.…”

Section: Introductionmentioning

confidence: 99%

Control of exhaled SARS-CoV-2-laden aerosols in the interpersonal breathing microenvironment in a ventilated room with limited space air stability

Deng

Gong

et al. 2021

Journal of Environmental Sciences

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“…They introduced a dimensionless number, Gc number, to determine the indoor air stability condition. Gc number is the ratio of temperature or density difference (g ⋅ ∂ρ/ ∂g) to the inertia of the air parcel along the vertical direction (v ⋅ ∂v/∂y) and is defined as Gc =gLΔT/(T 0 v 0 2 ), where g is the gravitational acceleration, m/s 2 ; v 0 is the characteristic velocity, m/s; ΔT is the vertical temperature difference in the room, K; L is the room height, m; and T 0 is the characteristic temperature, K. When Gc >0, the indoor air was in stable conditions; when Gc < 0, the indoor air was in unstable conditions; when Gc = 0, the indoor air was in neutral conditions (Deng and Gong 2020;Wang et al 2014). Stable air is often seen in rooms with floor cooling (Zhou et al 2019;Olesen 1997) or ceiling heating (Safizadeh et al 2019), where indoor air often experiences a lock-up effect (Bjørn and Nielsen 2002;Gao et al 2012), while unstable air environment often occurs in floor-heating (Dehghan and Abdolzadeh 2018) or chilledceiling rooms (Alamdari et al 1998), where strengthened forced or natural convection occurs (Zhou et al 2017).…”

Section: Introductionmentioning

confidence: 99%

Assessment of personal exposure to infectious contaminant under the effect of indoor air stability

Deng

Gong

Chen

et al. 2021

Environ Sci Pollut Res

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The objective of this study is to understand the effect of indoor air stability on personal exposure to infectious contaminant in the breathing zone. Numerical simulations are carried out in a test chamber with a source of infectious contaminant and a manikin (Manikin A). To give a good visual illustration of the breathing zone, the contaminant source is visualized by the mouth of another manikin. Manikin A is regarded as a vulnerable individual to infectious contaminant. Exposure index and exposure intensity are used as indicators of the exposure level in the breathing zone. The results show that in the stable condition, the infectious contaminant proceeds straightly towards the breathing zone of the vulnerable individual, leading to a relatively high exposure level. In the unstable condition, the indoor air experiences a strong mixing due to the heat exchange between the hot bottom air and the cool top air, so the infectious contaminant disperses effectively from the breathing zone. The unstable air can greatly reduce personal exposure to the infectious contaminant in the breathing zone. This study demonstrates the importance of indoor air stability on personal exposure in the indoor environment and provides a new direction for future study of personal exposure reduction in the indoor environment.

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Numerical investigation of air stability in space capsule under low gravity conditions

Cited by 11 publications

References 15 publications

Effects of simulated weightlessness on thermal sweating of human body: An experimental study

Effects of simulated weightlessness on thermal sweating of human body: An experimental study

Control of exhaled SARS-CoV-2-laden aerosols in the interpersonal breathing microenvironment in a ventilated room with limited space air stability

Assessment of personal exposure to infectious contaminant under the effect of indoor air stability

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