Roofs Supported by Air Pressure

Thermal performance of non air-conditioned buildings with vaulted roofs in comparison with flat roofs

Vaulted or domed roofs have been frequently adopted by builders and architects throughout the Middle East and other hot dry areas. However, the thermal performance of such buildings under hot dry climatic conditions has rarely been quantitatively studied. In this paper, a detailed finite element model for the investigation of the thermal performance of non air-conditioned buildings with vaulted...

Wind pressure measurements on full scale flat roofs

A flat roof surface is known to be subjected to unusually high suction associated with a pair of vortices created under diagonally skewed wind. Prediction of the wind load and its influence on the roof system is an important engineering topic but wind tunnel testing of this situation is not easy with a scaled model. Considering the physics of wind flow for the most critical case, a possibility ...

High-speed Electrical Motor/generator Supported by Air Bearings

This paper reports on the development of a high-speed electrical machine which can be used as motor or generator for application in micro heat engines. The machine has a rated power of 200 W at a rotational speed of 600 000 rpm and is supported by self-acting air bearings. The design process outlined in the paper focuses on aspects such as electromagnetic design, bearing design, rotordynamic be...

AIR PRESSURE SIMULATION IN CASTING MOLDS

During mold filling, molten metal can only advance as quickly as the air inside thecavity is expelled. In this work an analytical model describing air flow is developed based on aincompressible flow theory. Air pressure has serious effects upon the filling behaviour such assurface profile and filling time. In this work a new mathematical model is proposed for calculationthe air pressure during ...

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