An experimental study on the evaluation of natural ventilation performance of a two-sided wind-catcher for various wind angles

Abstract

a b s t r a c tNatural ventilation performance of a two-sided wind-catcher is investigated for various wind angles (a ¼ 0 e90 ) and wind speeds by experimental wind tunnel and smoke flow visualization. A 1:50 scale model of a real wind-catcher in the city of Yazd (Iran) is employed. The pressure coefficient as well as velocity are measured by pressure taps and hot-wire anemometer, respectively. The hot-wire results are used to evaluate the induced airflow rate and turbulence intensity. Smoke flow visualization techniques are employed to study the flow structure and patterns inside and outside of the wind-catcher. The results indicate that the wind direction has a large influence on the wind-catcher performance and the induced airflow rate increases with increasing the wind speed. The hot-wire results show that the transition angles of the house window and windward opening for all wind speeds occur at the wind angles of 39 and 55 , respectively. An excellent agreement is also found for these transition angles when they are determined by measured pressure coefficients. Based on measured quantities, it is found that the windcatcher acts as a chimney for the wind angle larger than the windward transition angle (a ¼ 55 ) and the highest ventilation rate occurs at the wind angle of 90 .

Evaluation of a two-sided windcatcher integrated with wing wall (as a new design) and comparison with a conventional windcatcher

“…Different researchers studied the ventilation performance of two-sided windcatcher as well as other types of windcatcher by wind tunnel testing and numerical method [5], [21] and [14]. In addition, few investigations evaluated the performance of wing wall -alone-for natural ventilation.…”

“…Afshin et al [5] investigated ventilation performance of a two-sided windcatcher for different wind angles ( from 0° to 90°) by wind tunnel experiment. A 1:50 reduced-scale model of a conventional two-sided windcatcher in the city of Yazd (Iran) was modeled.…”

“…In this regard, one promising solution that has gained attention is incorporating free and natural resources from nature such as natural ventilation [4]. Recently, natural ventilation techniques such as windcatchers are increasingly being employed in new buildings for increasing the fresh air rates and reducing the energy consumption [2] and [5].…”

Anti-short-circuit device: A new solution for short-circuiting in windcatcher and improvement of natural ventilation performance

“…Afshin et al [22] also investigated the natural ventilation performance of a two-sided windcatcher for various wind angles using wind tunnel and smoke testing. The smoke testing revealed that the air streams towards the bottom of the windcatcher channel are divided into two; the first stream tends to move to the room below.…”

Advanced Strategies for Net-Zero Energy Building: Focused on the Early Phase and Usage Phase of a Building’s Life Cycle

“…(3) Natural ventilation: To implement nZEB, an architectural design for inducing the reduction of the building energy demand through the effective influx of the outdoor air (i.e., natural ventilation) should be considered in the initial design stage. Generally, natural ventilation can be categorized based on two mechanisms: (i) buoyancy-driven ventilation by the vertical and horizontal temperature difference; and (ii) wind-driven ventilation by the pressure difference between the front and the back of the building (refer to Table 3) [29][30][31][32][33][34][35][36][37][38]. First, there are various previous studies related to buoyancy-driven ventilation [29][30][31][32][33][34].…”