A novel aerodynamic controllable roof for improving performance of INVELOX wind delivery system

2020 ◽  
pp. 0309524X2091098
Author(s):  
Ali Golozar ◽  
Farzad A Shirazi ◽  
Shahin Siahpour ◽  
Fardad N Khakiani ◽  
Kambiz Gaemi Osguei
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fuzzy Control ◽  
Ground Level ◽  
Model Structure ◽  
Performance Curve ◽  
System Efficiency ◽  
Roof Structure ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations

INVELOX is a patented structure designed to capture the incident wind from every direction, guide the collected wind to the ground level, and increase its velocity. A novel mechanism called aerodynamic controllable roof structure is introduced to improve the wind stream performance of INVELOX. The advantages of aerodynamic controllable roof structure are twofold: improving efficiency and preventing wind escaping the system. Using aerodynamic controllable roof structure, a performance curve is obtained that can improve the system efficiency. Wind speed and orientation and structural deflection are the parameters that direct the roof orientation. Fuzzy control is utilized in a model structure to control the roof movements using two servo motors. Computational fluid dynamics simulations are done to validate the performance and capability of the aerodynamic controllable roof structure mechanism. Results show that the fuzzy control is successful in controlling the roof orientation and the results from the simulation indicate that the efficiency of the system can be increased up to 12%.

scholarly journals Aerodynamic analysis of uphill drafting in cycling

2021 ◽  
Vol 24 (1) ◽  
Author(s):  
T. van Druenen ◽  
B. Blocken
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Speed ◽  
Scientific Literature ◽  
Sensitivity Analyses ◽  
Air Resistance ◽  
Wind Tunnel Measurements ◽  
Aerodynamic Effect ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations

AbstractSome teams aiming for victory in a mountain stage in cycling take control in the uphill sections of the stage. While drafting, the team imposes a high speed at the front of the peloton defending their team leader from opponent’s attacks. Drafting is a well-known strategy on flat or descending sections and has been studied before in this context. However, there are no systematic and extensive studies in the scientific literature on the aerodynamic effect of uphill drafting. Some studies even suggested that for gradients above 7.2% the speeds drop to 17 km/h and the air resistance can be neglected. In this paper, uphill drafting is analyzed and quantified by means of drag reductions and power reductions obtained by computational fluid dynamics simulations validated with wind tunnel measurements. It is shown that even for gradients above 7.2%, drafting can yield substantial benefits. Drafting allows cyclists to save over 7% of power on a slope of 7.5% at a speed of 6 m/s. At a speed of 8 m/s, this reduction can exceed 16%. Sensitivity analyses indicate that significant power savings can be achieved, also with varying bicycle, cyclist, road and environmental characteristics.

scholarly journals Evaluation of Active Heat Sinks Design under Forced Convection—Effect of Geometric and Boundary Parameters

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2041
Author(s):  
Eva C. Silva ◽  
Álvaro M. Sampaio ◽  
António J. Pontes
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Additive Manufacturing ◽  
Pressure Drop ◽  
Forced Convection ◽  
Thermal Performance ◽  
Heat Sinks ◽  
Trapezoidal Shape ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations

This study shows the performance of heat sinks (HS) with different designs under forced convection, varying geometric and boundary parameters, via computational fluid dynamics simulations. Initially, a complete and detailed analysis of the thermal performance of various conventional HS designs was taken. Afterwards, HS designs were modified following some additive manufacturing approaches. The HS performance was compared by measuring their temperatures and pressure drop after 15 s. Smaller diameters/thicknesses and larger fins/pins spacing provided better results. For fins HS, the use of radial fins, with an inverted trapezoidal shape and with larger holes was advantageous. Regarding pins HS, the best option contemplated circular pins in combination with frontal holes in their structure. Additionally, lattice HS, only possible to be produced by additive manufacturing, was also studied. Lower temperatures were obtained with a hexagon unit cell. Lastly, a comparison between the best HS in each category showed a lower thermal resistance for lattice HS. Despite the increase of at least 38% in pressure drop, a consequence of its frontal area, the temperature was 26% and 56% lower when compared to conventional pins and fins HS, respectively, and 9% and 28% lower when compared to the best pins and best fins of this study.

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