The influence of exterior louver blinds’ geometric and thermal attributes on the convective heat transfer at building facades

Jiang, Fujian; Li, Zhengrong; Zhao, Qun; Tao, Qiuhua; Lu, Shunyao; Zhao, Ke

doi:10.1016/j.solener.2019.09.074

Cited by 13 publications

(10 citation statements)

References 36 publications

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“…El intercambio de calor por convección (Q cv ) para un modelo se puede expresar como el proceso de convección de calor entre las superficies internas y externas de la envoltura de una superficie como se expresa en la Ecuación (2) [15].…”

Section: Figura 4 Red De Resistencias Térmicas En Un Colector Solarunclassified

Análisis numérico de un sistema de calentamiento de agua utilizando un colector solar de placa plana

et al. 2020

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El objetivo de la presente investigación fue realizar un análisis numérico mediante CFD de un colector solar de placa plana; además, se realizó una comparación con resultados experimentales. El fluido de trabajo alcanzó una temperatura máxima de salida de 20.16 °C a las 12:00, el valor de la radiación solar se determinó para las coordenadas geográficas latitud –0.2252 y longitud –77.84; de forma similar, en este horario fue posible obtener una temperatura de la superficie del colector de 27.12 °C, como valor pico. Se determinó el menor rendimiento del dispositivo de transferencia de calor a las 10:00 con un valor de temperatura de salida del agua y temperatura máxima en la superficie del colector de 18.65 y 20.48 °C, respectivamente. Los resultados experimentales mostraron una temperatura máxima de 20.93 °C y una temperatura mínima de19.4 °C, derivando en un error de 4.01 % entre la simulación computacional y los datos experimentales.

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Section: Figura 4 Red De Resistencias Térmicas En Un Colector Solarunclassified

Análisis numérico de un sistema de calentamiento de agua utilizando un colector solar de placa plana

et al. 2020

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“…Numerous studies have been performed to analyze various aspects of louvers. 7,24,[32][33][34][35][36][37][38][39] Some of them focused on the use of louvers as shading devices to control daylight 39 and heat gain, 37 on the increasing natural airflow in the double-glazed façades, 38 and on the performance of the windcatcher. 7 Liu et al 7 carried out CFD simulations to evaluate the effect of the length and the number of layers of louvers in the inlet, on the performance of the wind-catcher.…”

Section: Introductionmentioning

confidence: 99%

“…Also, several studies have investigated natural ventilation through louvered openings considering the influence of louvers orientation and/or slat angles. 24,32,34,37 Kosutova et al 24 performed wind-tunnel experiments and CFD simulations to investigate the impact of four different opening locations of a generic isolated building equipped with louvers on the indoor air velocity, airflow pattern, age of air and air exchange efficiency. They reported that CFD results with the RSM turbulence model have a very good agreement with experiment data, and the highest velocity occurs when openings are in the upper part of the façade.…”

Section: Introductionmentioning

confidence: 99%

Louver and window position effect on cross-ventilation in a generic isolated building: A CFD approach

Yazarlou

Barzkar

2022

Indoor and Built Environment

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Natural ventilation has been used to increase indoor air quality, remove pollutants, and remove heat absorbed in the building structure. Some architectural features such as wind-catcher systems are used to induce airflow into buildings, and openings equipped with louvers are employed to reduce solar daylight while allowing natural ventilation. Earlier studies on ventilated louvers and wind-catchers have shown the impact of the louvers’ opening positions and slat angles. However, their combination with each other has been less studied. This paper presents CFD simulations of cross-ventilation in a generic isolated building integrated with a one-sided roof-top wind-catcher and the outlet opening, both equipped with louvers for three different window opening positions. The isothermal 3D steady RANS equations were solved with the Standard k- ε method. The CFD simulations with CFX software were validated with the wind-tunnel experiments. The results show that the lowest dimensionless wind velocities inside the building were observed for the arrangement “Down” for both cases with and without louvers. In contrast, the highest air exchange efficiency and dimensionless wind velocities inside the building were measured for the arrangement “Up” for the case with louvers. This research can be considered as an architectural strategy to improve indoor natural cross-ventilation.

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“…Babakhani et al [18] investigated the forced convective heat exchange at the façade with different building geometries and wind directions, in which a coefficient F was developed to modify the correlation between Nu and Re. In addition to the geometry of the building itself, the surroundings may also change the h c /Nu at the façade, such as adjacent buildings in the street canyon [19] and exterior components attached to the façade [20,21]. For the latter one, Jiang et al [21] analyzed the convective heat exchange of the windward building façade with louver blinds.…”

Section: Introductionmentioning

confidence: 99%

“…In addition to the geometry of the building itself, the surroundings may also change the h c /Nu at the façade, such as adjacent buildings in the street canyon [19] and exterior components attached to the façade [20,21]. For the latter one, Jiang et al [21] analyzed the convective heat exchange of the windward building façade with louver blinds. It was found that the barrier effects of exterior louver shadings will suppress the convective heat transfer at the façade and cause a lower h c /Nu than that without blinds, and the louver blinds will replace the façade to mainly generate the convective heat loss of the building skins.…”

Section: Introductionmentioning

confidence: 99%

Investigation on Forced Convective Heat Transfer at the Building Façade with Louver Blinds under Different Wind Directions

Tao

et al. 2022

Buildings

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Exterior louver blinds are one of the most common shading devices attached to the building façade, which will not only screen solar radiation but also affect the flow around the building and change the convective heat exchange at the façade. To better understand how different wind directions affect the convective heat properties of louvered building façades, this paper conducted a CFD simulation with the validation of previous wind-tunnel experiments. A total of 63 shading cases and 7 unshaded cases were both investigated by simulations. It was found that with the increase in wind attack angle θ, the surface-averaged convective heat transfer coefficient (CHTC) at the louvered surface will first increase by about 40~50% (θ from 0° to 60°) and then be cut down by 60% (θ from 60° to 90°). In addition, the convective heat exchange rate at the louver slats will gradually decrease with the growth of θ. Finally, modifications for previous correlations were proposed to quantify the effect of wind directions on the CHTCavg at the blinds and façade, of which the maximum deviation for convective heat exchange rate is less than 18%.

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The influence of exterior louver blinds’ geometric and thermal attributes on the convective heat transfer at building facades

Cited by 13 publications

References 36 publications

Análisis numérico de un sistema de calentamiento de agua utilizando un colector solar de placa plana

Análisis numérico de un sistema de calentamiento de agua utilizando un colector solar de placa plana

Louver and window position effect on cross-ventilation in a generic isolated building: A CFD approach

Investigation on Forced Convective Heat Transfer at the Building Façade with Louver Blinds under Different Wind Directions

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