8 research outputs found

    Numerical study of the air distribution in the Crew Quarters on board of the International Space Station

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    The current concept of Crew Quarters on board of the International Space Station has several issues according to the crew member’s feedback. Major issues concern noise levels, the accumulation of CO2 and the quality of the air distribution. Our study targets the airflow distribution, to diagnose this issue, we realise a series of numerical simulations (CFD) based on a real scale replica of the Crew Quarters. Simulations were set with a zero-gravity mode and with the theoretical air parameters inside the SSI. The geometry includes a thermal manikin having the neutral posture of a body in the absence of gravity. Numerical simulations were run for the three different air flow rates provided by the current ventilation system. Results have shown that the air distribution inside the Crew Quarter is insufficient for low airflow rates but becomes acceptable for the higher airflow rate, however the higher airflow rate can potentially produce draught discomfort

    Numerical simulation and comparison of two ventilation methods for a restaurant – displacement vs mixed flow ventilation

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    This paper presents a comparison between a displacement ventilation method and a mixed flow ventilation method using computational fluid dynamics (CFD) approach. The paper analyses different aspects of the two systems, like the draft effect in certain areas, the air temperatureand velocity distribution in the occupied zone. The results highlighted that the displacement ventilation system presents an advantage for the current scenario, due to the increased buoyancy driven flows caused by the interior heat sources. For the displacement ventilation case the draft effect was less prone to appear in the occupied zone but the high heat emissions from the interior sources have increased the temperature gradient in the occupied zone. Both systems have been studied in similar conditions, concentrating only on the flow patterns for each case

    Numerical Simulation Investigation of a Double Skin Transpired Solar Air Collector

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    Transpired solar collectors (TSC) are one of the most popular solar thermal technologies for building façades. TSC use solar energy to heat the absorber surface, which transmits thermal energy to the ambient air. A variant of TSC, namely, a double skin transpired solar collector (DSTSC), has been analyzed in this paper, thus providing guide values and a technical point of view for engineers, architects, and constructors when designing such transpired solar collectors. Three important parameters were addressed in this study through numerical simulation: the influence of a separation plate introduced in a TSC, turning it into a DSTSC; the air layer thickness influence on the performance of the collector; and the influence of the used absorber materials for the separation plate material. Greater heat exchange efficiency was noticed for the DSTSC at every imposed airflow rate compared with the TSC. Regarding the thickness of the collector, the efficiency gradually increased when increasing the solar collector thickness until it reached a value of 20 cm, though not varying significantly at a thickness of 30 cm

    Numerical simulation and comparison of two ventilation methods for a restaurant – displacement vs mixed flow ventilation

    No full text
    This paper presents a comparison between a displacement ventilation method and a mixed flow ventilation method using computational fluid dynamics (CFD) approach. The paper analyses different aspects of the two systems, like the draft effect in certain areas, the air temperatureand velocity distribution in the occupied zone. The results highlighted that the displacement ventilation system presents an advantage for the current scenario, due to the increased buoyancy driven flows caused by the interior heat sources. For the displacement ventilation case the draft effect was less prone to appear in the occupied zone but the high heat emissions from the interior sources have increased the temperature gradient in the occupied zone. Both systems have been studied in similar conditions, concentrating only on the flow patterns for each case

    Numerical Simulation Investigation of a Double Skin Transpired Solar Air Collector

    No full text
    Transpired solar collectors (TSC) are one of the most popular solar thermal technologies for building façades. TSC use solar energy to heat the absorber surface, which transmits thermal energy to the ambient air. A variant of TSC, namely, a double skin transpired solar collector (DSTSC), has been analyzed in this paper, thus providing guide values and a technical point of view for engineers, architects, and constructors when designing such transpired solar collectors. Three important parameters were addressed in this study through numerical simulation: the influence of a separation plate introduced in a TSC, turning it into a DSTSC; the air layer thickness influence on the performance of the collector; and the influence of the used absorber materials for the separation plate material. Greater heat exchange efficiency was noticed for the DSTSC at every imposed airflow rate compared with the TSC. Regarding the thickness of the collector, the efficiency gradually increased when increasing the solar collector thickness until it reached a value of 20 cm, though not varying significantly at a thickness of 30 cm

    Numerical simulation and comparison of two ventilation methods for a restaurant – displacement vs mixed flow ventilation

    No full text
    This paper presents a comparison between a displacement ventilation method and a mixed flow ventilation method using computational fluid dynamics (CFD) approach. The paper analyses different aspects of the two systems, like the draft effect in certain areas, the air temperatureand velocity distribution in the occupied zone. The results highlighted that the displacement ventilation system presents an advantage for the current scenario, due to the increased buoyancy driven flows caused by the interior heat sources. For the displacement ventilation case the draft effect was less prone to appear in the occupied zone but the high heat emissions from the interior sources have increased the temperature gradient in the occupied zone. Both systems have been studied in similar conditions, concentrating only on the flow patterns for each case
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