AIR FLOW PATTERNS IN AN AIR CONDITIONED MEASURING EQUIPMENT LABORATORY | ||||
| The International Conference on Applied Mechanics and Mechanical Engineering | ||||
| Article 3, Volume 13, 13th International Conference on Applied Mechanics and Mechanical Engineering., May 2008, Page 31-47 PDF (587.18 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/amme.2008.38941 | ||||
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| Authors | ||||
| FARAG A. M.1; KHALIL E. E.2; MORKOS S. M.2 | ||||
| 1Egyptian Air Force. | ||||
| 2Mechanical Power Engineering Department , Faculty of Engineering, Cairo University, Cairo, Egypt. | ||||
| Abstract | ||||
| ABSTRACT Calibration for the measuring instruments in the Air Force Measuring Equipment Laboratories, are considered to be one of the reasons for flight success in Egyptian Air Force. Hence, they should be preserved from the different factors that might cause harm or decrease the accuracy in calibration for the measuring instruments. One of these factors is the excessive relative humidity as it affects the mechanical and physical properties of the standard instruments that are considered the reference. Measuring instruments need to be calibrated from time to time to provide high accuracy in use that occurs by comparing a measuring device (uncalibrated) against an equal or better standard. The present paper focuses on the heat transfer interactions on the air flow in Precision Measuring Equipment Laboratories (PMEL). Many PMELs built or renovated in recent years have not met minimum operating environment standards. The impact of flow parameters on the air flow pattern were investigated. This offers the designer a better view of design limits to enable him to adequately select the optimum design from a wide number of alternative options and to use them in forecasting and even monitoring. Air movement inside enclosures prediction via CFD is a strong tool for reaching better designs for inlets and outlets positions in ventilated spaces. Fluent Computational Software [1] was used to predict the parameters affecting the air distribution inside airconditioned spaces. Continuity, momentum, energy, and species transport equations in addition to k-epsilon model equations for turbulence closure were solved using finite volume method. Furthermore the paper includes full-scale actual existing space experiments, to obtain good documented full-scale measurements in actual ventilated laboratory room that can be used for comparison with CFD-simulations. Many of the reported comparisons were found in good agreement with experiments and aided the assessment of the numerical procedure application to air-conditioned spaces. Finally, it was found that the optimum airside system design should allow the air to pass all the enclosure areas before being extracted. Temperature and humidity control are crucial elements of laboratory design. Since temperature fluctuations also affect humidity, its control is especially important. Also a restriction should be made for the mechanical and optical disciplines, the internationally accepted temperature is not exceed 20°C. | ||||
| Keywords | ||||
| Air-conditioned; calibration; Measuring; Equipment; CFD | ||||
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