A low‐energy approach to process large scale airflow

A simplified solar updraft device adapted from the Trombe wall concept was built to process large-scale airflow using only solar energy. The performances were systematically studied using experimental measurements and numerical models, with the focus of investigating whether this device can generate enough airflow under low solar intensities, and developing a fast-analytical mathematical model to effectively and efficiently find design rules for further application. The experimental results prove that the air mass flow rate generated by solar updraft in a 0.9 m ² solar updraft device can be as high as 75.6 kg/h when the solar radiation is only 120 W/m ². A comparison of two numerical models shows that it is feasible to develop a fast-analytical tool based on widely available MATLAB with low demand for computing resources and to provide guidance on how a future device should be designed for particular applications. The study also investigated the effects of a wider range of solar radiation intensities, air channel height and thickness on the updraft performances (e.g., air temperature, airflow velocity, and mass flow rate).