Statistical analysis of turbulent thermal convection in a cabin mockup

Zhang, Yongzhi; Liu, Junjie; Wang, Congcong

doi:10.1016/j.buildenv.2017.01.012

Cited by 13 publications

(10 citation statements)

References 33 publications

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“…The flow field around a thermal manikin operated at 75 W seated in a closed chamber was investigated by Li et al 9 using particle image velocimetry in multiple planes. Their results revealed thermal boundary layer thicknesses similar to those described by Zhang et al 5 and a stronger flow in front of the manikin as compared to its back. In a previous publication, we already investigated the impact of the heat release rate of thermal manikins and real passengers on displacement ventilation.…”

Section: Introductionsupporting

confidence: 77%

“…To our best knowledge, measurements are currently either conducted with thermal manikins at constant heat release (e.g. Bosbach et al 3 , Cao et al 4 , Zhang et al 5 ), or with heating mats as described and depicted 1,6,7 which do not simulate the shape and the blockage of the passengers. Even though some manikins with a coupled thermoregulation model are commercially available, 8 due to their high price and therefore limited availability, such manikins are usually not used for the investigation of large compartments.…”

Section: Introductionmentioning

confidence: 99%

“…Even though some manikins with a coupled thermoregulation model are commercially available, 8 due to their high price and therefore limited availability, such manikins are usually not used for the investigation of large compartments. Zhang et al 5 addressed the properties of the thermal plume around a thermal manikin operated at 75 W in detail, revealing a thermal boundary layer thickness of 40 mm. The flow field around a thermal manikin operated at 75 W seated in a closed chamber was investigated by Li et al 9 using particle image velocimetry in multiple planes.…”

Section: Introductionmentioning

confidence: 99%

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Influence of shape and heat release of thermal passenger manikins on the performance of displacement ventilation in a train compartment

Schmeling

Bosbach

2019

Indoor and Built Environment

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The influence of sensible heat release on the performance of displacement ventilation was studied in a generic laboratory representing the lower cabin of the German Aerospace Center (DLR)’s Next Generation Train. Tests at variable mean cabin temperatures were conducted with human subjects, thermal manikins and heating mats at different but constant heat release rates. Moreover, tests with thermal manikins and an adaptive heat release rate were performed. Flow fields, surface temperature distributions as well as local temperatures and velocities were evaluated. The study revealed that the shape of the heat sources is negligible if only global quantities, such as the global enthalpy flux or the heat removal efficiency, are evaluated. The latter was found to be independent of the amount of released heat. However, it strongly reacts to the choice of probe positions used for the mean cabin temperature. Regarding the comfort-relevant flow parameters, both the shape and the heat release rate are highly relevant to temperature stratifications and flow fields in the passenger zone. The manikins with adaptive heat release proved to be a major improvement in terms of realistic simulation of the human metabolism for investigations regarding the performance of ventilation systems. However, the determination of the mean cabin temperature receives increased relevance as it is prone to limit the closeness to reality.

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Section: Introductionsupporting

confidence: 77%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Influence of shape and heat release of thermal passenger manikins on the performance of displacement ventilation in a train compartment

Schmeling

Bosbach

2019

Indoor and Built Environment

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“…For investigation of the air distribution in aircraft cabins, laboratory tests have been carried out in small cabin mock‐ups to characterize the jets along the diffusers, the main flow in the cabin, thermal plumes from heated manikins, and gasper‐induced flow . At the same time, efforts have been made to evaluate contaminant transport in cabins.…”

Section: Introductionmentioning

confidence: 99%

Evaluating the commercial airliner cabin environment with different air distribution systems

You

Lin

Wei³

et al. 2019

Indoor Air

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Ventilation systems for commercial airliner cabins are important in reducing contaminant transport and maintaining thermal comfort. To evaluate the performance of a personalized displacement ventilation system, a conventional displacement ventilation system, and a mixing ventilation system, this study first used the Wells-Riley equation integrated with CFD to obtain the SARS quanta value based on a specific SARS outbreak on a flight. This investigation then compared the three ventilation systems in a seven-row section of a fully occupied, economy-class cabin in Boeing 737 and Boeing 767 airplanes. The SARS quanta generation rate obtained for the index patient could be used in future studies. For all the assumed source locations, the passengers' infection risk by air in the two planes was the highest with the mixing ventilation system, while the conventional displacement ventilation system produced the lowest risk. The personalized ventilation system performed the best in maintaining cabin thermal comfort and can also reduce the infection risk. This system is recommended for airplane cabins. K E Y W O R D S computational fluid dynamics (CFD), displacement ventilation, infectious disease transmission, mixing ventilation, personalized ventilation, thermal comfort | 841 YOU et al.

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“…On the other hand, due to higher passenger density in aircraft cabin, the natural convection (thermal plume) is generated by the buoyancy force stemming from the temperature difference between passengers and the surrounding air (Craven and Settles 2006). Recently, the thermal plume is of great concern, and it has been found that the influence of thermal plume on the cabin environment cannot be ignored (Kühn et al 2009;Yan et al 2016;Zhang et al 2017). Li et al (2017) and Wang et al (2018) studied the steady and unsteady characteristics of thermal plume generated by one heated manikin in a 7-row cabin mockup using experiment method, although the effect of the forced convection was not considered.…”

Section: Introductionmentioning

confidence: 99%

A modified turbulence model for simulating airflow aircraft cabin environment with mixed convection

Zhao

Liu

et al. 2020

Build. Simul.

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The forced convection (air supply jet) and the natural convection (thermal plume of passenger) co-exist in an aircraft cabin simultaneously. Due to the notable difference of the Reynolds numbers for the two convection processes, the traditional RANS method can hardly simulate the forced/natural convection flows accurately at the same time. In addition, the large geometric ratio between the main air supply inlet and the whole cabin leads to difficulties in grid generation for the cabin space. An efficient computational model based on the standard k-ε model is established to solve these problems. The coefficients in the dissipative equation are modified to compensate the enlarged numerical dissipation caused by coarse grid; meanwhile, the piecewise-defined turbulent viscosity is introduced to combine the forced and natural convection. The modified model is validated by available experimental results in a Boeing 737-200 mock-up. Furthermore, the unsteady characteristic of the aircraft cabin environment is obtained and analyzed. According to the frequency analysis, it turns out that the thermal plume is the main factor of the unsteady fluctuation in cabin. Keywordsaircraft cabin environment, modified turbulence model, mixed convection flow, modified dissipation coefficients, piecewise-defined turbulent viscosity

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Statistical analysis of turbulent thermal convection in a cabin mockup

Cited by 13 publications

References 33 publications

Influence of shape and heat release of thermal passenger manikins on the performance of displacement ventilation in a train compartment

Influence of shape and heat release of thermal passenger manikins on the performance of displacement ventilation in a train compartment

Evaluating the commercial airliner cabin environment with different air distribution systems

A modified turbulence model for simulating airflow aircraft cabin environment with mixed convection

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