EE- Enerji Bilim ve Teknoloji Lisansüstü Programı - Yüksek Lisans
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ÖgeNumerical İnvestigation Of Flow İn A Channel With Porous Baffles(Energy Institute, 2018-10-23) Baş, Ahmet ; Baytaş, Ayşe Filiz ; 301141030 ; Energy Sciences and Technologies ; Enerji Bilim ve TeknolojiPorous materials have been used for more than many other materials types known to humans. From daily use such as bath or kitchen sponges to more general use like building bricks, one can see how common porous materials really are. Furthermore, industrialization of them started only a couple of hundred years from today. It was first Henri Darcy, a French engineer specilized on hydraulics, who investigated the properties of porous materials such as porosity and permability. His work led many other scientists to focus on these properties and help the industrialization process. In recent years, investigations started to merge with modern world problems as in energy or automotive industries and related ecological problems. In the aim of creating a sustainable structure for any industry in addition to aforementioned ones, one must look for higher efficiency. For higher efficiency, the next step to take is decreasing the number of entropy generators or actually reducing their effect as it is a fact that entropy always happens. For this purpose, this work focuses on the one the major entropy generators, that is, unused or wasted heat by inspecting the streams of flow in a channel with the help of porous baffles put in front of the flow. Considering the local heat transfer amounts, it was aimed to find the best case of heat transfer by comparing different cases of baffle positions. Other works also conducted in similar models contribute the progress of this study, validation of the model proposed and evaluation of results. As an initial step, a similar study of staggered and porous baffles was inspected. In said study; propagation of streamlines against baffles were inspected in terms of heat transfer and drag, for two fluids with different properties. In the second work, channel flow around solid baffles with different inclination angles was studied. Once the use of proposed model is confirmed, these two works were merged and analysed accordingly. During analysis, the latter model was selected as the base model for grid, boundary conditions and flow regime; however, different cases were produced by crossing different porous medium properties for baffles. Moreover, categorization was based on number and placement of baffles in the channel as well as their angle of inclination. After post-processing the analysis results, it was seen that the baffles that are positioned as staggered was the best case in terms of local Nusselt number and hence heat transfer capability as the baffle inclination angle was increased. On the other hand, contribution of porosity change was minimal to flow characteristics. Permeability effect was the opposite of expected, considering that the loss in flow speed would decrease convection heat transfer; however, the lower the permeability the higher was the heat transfer values due to recirculation strength created around the baffles. Eventually, in addition to above analytical results, an experimental research is always encouraged.