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The study of energy savings in ventilation systems within buildings is crucial. Impinging jet ventilation (IJV) systems have garnered significant interest from researchers. The identification of the appropriate location for the IJV reveals a gap in the existing literature. This research was conducted to address the existing gap by examining the impact of IJV location on energy savings and thermal comfort. A comprehensive three-dimensional CFD model is examined to accurately simulate the real environment of an office room (3 × 3 × 2.9 m3) during cooling mode, without the application of symmetrical plans. Four locations have been selected: two at the corners and two along the midwalls, designated for fixed-person positions. The return vent height is analyzed utilizing seven measurements: 2.9, 2.6, 2.3, 1.7, 1.1, 0.8, and 0.5 m. The RNG k–ε turbulence model is implemented alongside enhanced wall treatment. The findings indicated that the optimal range for the return vent height is between 1.7 and 0.8 m. It is advisable to utilize the IJV midwall 1 location, positioned behind the seated individual and away from the exterior hot wall. It is characterized by low vortex formation in the local working zone that contributes to a more comfortable sensation while providing recognized energy-saving potential.

The current study represents a numerical investigation of the pin fin heat sink performance with different angles of wings. Five angles ranging from 0° to 90° have been represented and studied under inline and staggered arrangements of pin fins. Reynolds numbers range from 13,500 to 37500. The highest Nusselt number has been achieved by angle-0° with inline arrangement while it has been achieved by angle-22.5° with staggered arrangement. On the other hand, the maximum friction factor with both inline and staggered arrangements is represented by angle-0°. The highest thermohydraulic performance has been achieved by angle-22.5° for staggered arrangement while case without wings gives the highest performance for inline arrangement. Using wings in staggered arrangement shows significant effect on heat transfer performance. While it is not recommended to use wings in case of inline arrangement.

Many options are devoted to enhancing heat transfer alongside lowering the pressure drop inside the tube banks in cross flow with air. Among these, is attaching splitter plates (SPs) to the trailing edges of the tubes as extended surfaces. That already proved from literature its effective use. Another proposed option is to increase the surface's roughness, with limited available data from literature. Thus, the present research was established to study the effect of using different surface roughness of a staggered tube-bank in cross flow with air on heat transferred and pressure drop besides the comparison with installing SPs. To this aim, a full 3D CFD model is developed to study the two mentioned options without any symmetrical boundary conditions. The study extended to include the effect of Remax changes from 5000 to 100,000. While three surface relative roughness; ks/D = 0 (smooth), ks/D = 0.01, and ks/D = 0.02 are investigated. The results confirmed that increasing heat transfer surface roughness helps to augment the total heat transferred. While a limited pressure drop increase is reported compared to installing SPs. Combining both; increasing surface roughness, and, adding SPs, led to multiplying the total heat transfer rate.

Time-dependent measurements are essential to describe the temperature and heat transfer coefficient development lead to understanding the unsteady nature of tunnel kiln behavior during cooling. The present paper introduces experimental investigations in a brick tunnel kiln equipped with a U-shape guide vane to monitor its transient thermal behavior. The experimental test rig of scale 1:4 has been fabricated for this purpose. Three U-shape guide vanes have attack angles (θ = 120°, 135°, and 150°) positioned in the flow direction are used to direct the flow to the confined zone among bricks columns. Two settings with a Reynolds number range from 14285 to 25480 are used. The results revealed that in absence of vanes, the average heat transfer coefficient (AHTC) has low values compared to that with vanes. The highest values of AHTC are obtained at vane angle θ = 135° , over the whole time. The Longitudinal middle bricks have the highest heat transfer coefficient for all vane angles due to high flow velocity with a good air-cooling rate. The maximum augmentation reached 48% at vane angle, θ = 135°, for setting 7. The guide vanes have beneficial features when used as a turbulence generator to improve the heat transfer rate from the brick setting.

This paper intentions to study the effect of using different tapered longitudinal section manifolds rather than the uniform one, in a Z shaped flat plate solar collector on; the uniformity of flow distribution, pressure drop, and consequently temperature profile. To this end, a 3D CFD model is planned to mimic a parallel piping network of Z configuration. Considering both fluid and piping body domains, and moreover, the inlet and outlet junctions, that would affect the resulted system pressure drop. The system has the following specifications: uniform header diameter of 20 mm, manifold and header lengths of 1150 mm, ten tubes, tubes diameter of 7 mm, tubes length of 1780 mm, horizontally mounted, and, with imposed solar radiation. Different taper ratios of the manifold, from 1.0 to 2.4 are studied against inlet ReD ranges from 300 to 2100. The model is validated with existing experimental outcomes from literature and showed an excellent agreement. Two indices are used to quantify the flow distribution uniformity. Generally the results concluded that, for enhanced flow distribution uniformity, an optimum taper ratio is important to be defined per each ReD.

The higher the process efficiency, the lower the fuel consumption, and the less impact carbon emissions have on the environment. The flow characteristics around brick settings are an important field of investigation to acquire control over the energy intake and production process. The current work is a numerical CFD investigation to demonstrate fluid flow characterization inside the cooling zone in a brick tunnel kiln for lattice settings (the number of bricks in each layer is identical). Four different lattice settings were examined, and three were validated with published experimental data (settings 1, 2 and 3). In the current study, the BSL κ-ω turbulent model agrees well with the published experimental results. The numerical investigation presents the flow characteristics through four different lattice brick settings (e.g., velocity vectors, velocity contours and streamlines) that could not be measured experimentally. The investigation also looks at the flow zones of the vortex formation upstream, downstream and through the brick column. It was discovered that for settings 1 and 11, the quick air flow in the wall channels is much greater than in the column channels. Setting 3 has a larger vortex formation region, whereas setting 1 has a weaker vortex than the other settings. The cooling of the lattice bricks in Setting 3 is superior to the cooling in the other settings.