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This work deals with a numerical parametric optimization study of a new Solar Flat Air Collector (SFAC) configuration. The CFD numerical parametric study investigates various SFAC structures inside the air cavity without obstacles and with spherical, cubic, cylindrical, and pyramidal obstacles. The study optimizes the most convenient configuration and arrangement that allow for the increase of the heat-transfer surface and to make the flow homogeneous in order to generate turbulence zones inside the SFAC air cavity. The result shows that the thermal performances of the cubic form are close to those of the spherical obstacles. Another set of simulations was performed to evaluate the performances of the cubic shape baffles for three orientation angles equal to 0°, 22.5°, and 45°, respectively. Each configuration has three forms of arrangement with a relative roughness pitch (b/a) varying between 2, 4, and 6. The results of the simulation study showed that the relative roughness pitch, the Reynolds number, as well as the angle of orientation influence the performance and the operation of the SFAC. The results of the simulations showed that the combination of an orientation of 45° with a roughness pitch of b/a = 2 increases the SFAC thermal performances, which can reach 85%.
This article, which is published in two parts, describes research that focuses on the analysis – through an experimental study – of the sealing behaviour of a non-contact dynamic sealing device known as a viscoseal (or sometimes called a helical groove seal). Despite its reliability and its advantageous characteristics, compared with other types of sealing devices, the viscoseal is still under-researched because of its complex characteristics. The experimental apparatus used in this work is equipped with two different test cells. This first, made from acrylic glass, is transparent and is used for the visualisation of the liquid–air interface within the viscoseal. The second cell, used for pressure measurement, is composed of bronze. The experimental results are compared with numerical results obtained using the Reynolds model and also with computational fluid dynamics code. The first instalment, which appears here, includes a general introduction and covers the experimental set-up and relevant references. Part II will be published in the September issue.
This article, which is published in two parts, describes research that focuses on the analysis – through an experimental study – of the sealing behaviour of a non-contact dynamic sealing device known as a viscoseal (or sometimes called a helical groove seal). Despite its reliability and its advantageous characteristics, compared with other types of sealing devices, the viscoseal is still under-researched because of its complex characteristics. The experimental apparatus used in this work is equipped with two different test cells. The first, made from acrylic glass, is transparent and is used for the visualisation of the liquid–air interface within the viscoseal. The second cell, used for pressure measurement, is composed of bronze. The experimental results are compared with numerical results obtained using the Reynolds model and also with computational fluid dynamics code.
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