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It is often necessary in fluid flow systems to simultaneously decelerate and turn the flow. This can be achieved by employing turning diffusers in the fluid flow systems. The flow through a turning diffuser is complex, apparently due to the expansion and inflexion introduced along the direction of flow. The flow characteristics of 3-D turning diffuser by means of varying inflow Reynolds number are presently investigated. The flow characteristics within the outlet cross-section and longitudinal section were examined respectively by the 3-D stereoscopic PIV and 2-D PIV. The flow uniformity is affected with the increase of inflow Reynolds number due to the dispersion of the core flow throughout the outlet cross-section. It becomes even worse with the presence of secondary flow, 22% to 27% of the mean outlet velocity. The flow separation takes place within the inner wall region at the point very close to the outlet edge and the secondary flow vortex occurs dominantly within half part of the outlet cross-section.

The small plug loads, or the Miscellaneous Electric Loads (MELs) in the tropical buildings typically account for up to 30% of the total electricity usage and is expected to rise in the near future. However, as compared to other energy consuming building systems, less attention has been paid to the MELs due to its elusive, more diversified and sophisticated nature. This study aims to identify the opportunity of energy efficiency improvement of the MELs in an institutional building in Malaysia, by focusing on the user behavioural action and power management features of equipment towards potential energy savings. The results obtained show that about 19% of the total energy demand can be reduced if all of the users turned off, unplugged or disconnected the office equipment when not required, and this lead to a significant reduction in greenhouse gases emission. This finding is particularly important for good energy demand management, as more and more modern electric appliances are introduced into the local commercial buildings which are contributing to the increase in energy consumption and subsequently, the utility bill.

This paper reports the findings from heat transfer studies with the presence of extended surfaces from tube banks which are termed as integral wake splitter plates. Employing this type of fins, investigations on heat transfer characteristics on a single circular tube as well as tube banks were carried out in cross flow of air in a rectangular duct. Experiments were carried out in the Reynolds number range 5 x 103 to 105 on a single cylinder of various splitter length-to-tube diameter ratios, L/D = 0.5, 1.0, 1.5 and 2.0. Further, tube banks consisting of 12 rows and 3 tubes per row in equilateral triangle arrangements with transverse pitch to diameter ratio, a = 2, were also investigated, the banks being made up of plain tubes or tubes with splitters. Heat transfer characteristics were studied for tubes with L/D = 0, 0.5 and 1.0 under constant heat flux conditions. Tube banks with L/D = 1.0 yielded the highest heat transfer rates. Findings from this work may be adopted to be utilized in various industrial applications such as economizer of a steam boiler, air-conditioning coils or waste heat recovery systems.