WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 2Citation - Scopus: 2Numerical Simulation of Flow and Dam Body Sediment Over a Movable Bed Due To an Earthfill Dam Break(Yıldız Teknik Üniversitesi, 2022) Tayfur, Gökmen; Tayfur, Gökmen; Issakhov, Alibek; Zhandaulet, Yeldos; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThis paper presents the numerical simulations of flow and dam body sediment transport over a movable bed due to an earthfill dam break. The RANS equations, together with the k-omega SST turbulent model, are employed. The phase characteristic parameter is used as the phases of air, water, sediment, and bulk of dam body. The system of equations is solved numerically using the PISO algorithm. The numerical model is first verified using the dam break experimental data from the literature. The model successfully captures the temporal changes in the measured flow depths, pressures, wave fronts, and arrival times. The ve rified mod el is then app lied to simulate the flow and sediment transport as a result of an artificial earthfill dam break having an obstacle at its downstream section. The simulations show that there is a noticeable decrease in the shock pressures at all points around the obstacle and there is an increase in the water levels. The bulk dam body sediment moves together with the water flow wh ile sp reading. It takes longer time for the sediment laden flow to reach the obstacle. The investigation of dam body formed by different soils shows that the soil type has minor effect while the transport of sediment can raise the water levels and change the morphology of the downstream section.Article Citation - WoS: 1Children in Urban Environments: a Case Study From a Dense Neighbourhood in Izmir-Turkey(Yıldız Teknik Üniversitesi, 2022) Dikmen Güleryüz, Oylum; Doğan, Fehmi; Doğan, Fehmi; Kasalı, Altuğ; 02.02. Department of Architecture; 02. Faculty of Architecture; 01. Izmir Institute of TechnologyThe aim of this study is to understand children's engagement with their urban outdoor environments in Izmir-Turkey, a city with a high urbanisation rate, and to explore the factors that affect their outdoor preferences outside of their school time. The study consists of a field study conducted in a densely populated middle-income neighbourhood. Participants are fourth-grade children from a state-run primary school aged 9-11 years (n=44) and their parents (n=40). The study followed a multi-methodological approach, employing questionnaires, drawing and story writing tasks as data collection methods. Results of the study showed the strong tendency to prefer outdoors during their free time even when their neighbourhood is a high-density urban settlement with limited opportunities for outdoor activities. In the studied neighbourhood, most of the participants mentioned the schoolyard over other locations as their preferred place fin- outdoor play. Other than the schoolyard, the children mainly reported familiar places in their neighbourhoods, close to their local environments which were also depicted in their drawings and described in their stories. From the perspectives of urban designers and policy-makers, the findings of the study highlight aspects to be concerned about opportunities for outdoor play in high-density and urbanised central neighbourhoods.Article Citation - WoS: 12Citation - Scopus: 11Inverted Fins for Cooling of a Non-Uniformly Heated Domain(Yıldız Teknik Üniversitesi, 2015) Çetkin, Erdal; Çetkin, Erdal; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThis paper shows that the peak temperature of a non-uniformly heated region can be decreased by embedding high-conductivity tree-shaped inserts which is in contact with a heat sink from its stem. The volume fraction of the high-conductivity material is fixed, and so is the volume of the solid region. The length scale of the solid domain is L. Inside there is a cube-shaped region with length scale of 0.1L and heat production 100 times greater than the rest of the domain. The location of this hot spot was varied to uncover how its location affects the peak temperature and the design of inverted fins, i.e. highconductivity tree-shaped inserts. The volume fraction of the high-conductivity tree was varied for number of bifurcation levels of 0, 1 and 2. This showed that increasing the number of the bifurcation levels decreases the peak temperature when the volume fraction decreases. The optimal diameter ratios and optimal bifurcation angles at the each junction level are also documented. Y-shaped trees promise smaller peak temperatures than T-shaped trees. The location of the vascular tree in the z direction also affects the peak temperature when the heat generation is non-uniform. In addition, the peak temperature is minimum when z = 0.65L even though the hot spot is located on z = 0.75L.Article Citation - WoS: 3Citation - Scopus: 4Constructal Structures for Self-Cooling: Microvascular Wavy and Straight Channels(Yıldız Teknik Üniversitesi, 2015) Çetkin, Erdal; Çetkin, Erdal; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThis paper shows that a conductive domain which is subjected to heating from its bottom can be cooled with embedded microvascular cooling channels in it. The volume of the domain and the coolant are fixed. The actively cooled domain is mimicked from the human skin (which regulates temperature with microvascular blood vessels). The effect of the shape of cooling channels (sinusoidal or straight) and their locations in the direction perpendicular to the bottom surface on the peak and average temperatures are studied. In addition, the effect of pressure difference in between the inlet and outlet is varied. The pressure drop in the sinusoidal channel configurations is greater than the straight channel configurations for a fixed cooling channel volume. The peak and average temperatures are the smallest with straight cooling channels located at y = 0.7 mm. Furthermore, how the cooling channel configuration should change when the heat is generated throughout the volume is studied. The peak and average temperatures are smaller with straight channels than the sinusoidal ones when the pressure drop is less than 420 Pa, and they become smaller with sinusoidal channel configurations when the pressure drop is greater than 420 Pa. In addition, the peak and average temperatures are the smallest with sinusoidal channels for a fixed flow rate. Furthermore, the peak temperatures for multiple cooling channels is documented, and the multiple channel configurations promise to the smallest peak temperature for a fixed pressure drop value. This paper uncovers that there is no optimal cooling channel design for any condition, but there is one for specific objectives and conditions.Article Citation - WoS: 4Impact of Window-To Surface Area for Different Window Glass Types and Wall Orientations on Building Energy Performance: a Case Study for a School Building Located in Izmir, Turkey(Yıldız Teknik Üniversitesi, 2011) Yildiz, Yusuf; Durmuş Arsan, Zeynep; Ozbalta, Trkan Goksal; Arsan, Zeynep Durmus; 02.02. Department of Architecture; 02. Faculty of Architecture; 01. Izmir Institute of TechnologyThe opaque and transparent surfaces of buildings have an important role in the total percentage of energy loss or gain. Heat loss or gain from windows are dependent on the window-to-wall area ratio, the window glass type, and the type of window frame used. In the concept of energy efficient design, heat loss or gain from windows should be analyzed in detail in the early stages of building design by considering local climatic conditions. This study investigates a school building located in Izmir in Turkey, a city with a hot and humid climate. Various glass types with different glazing characteristics and number of layers, located in different parts of the buildings and with different window-to-wall ratios are analyzed and compared using building the energy analysis program "EnergyPlus". Results indicate that window-to-wall area ratios, wall orientation and glass types are important factors in the building's total energy consumption. When the window-to-wall area ratio is increased from 10% to 60%, the winter heating load of the building decreases in maximum amount on the south side of the building and reduces in minimum amount on the east side of the building. When summer cooling load is investigated the highest increase in energy consumption is found on the south side of the building. On the eastern and western sides of the building the effect of increased energy consumption value remains low. When the total energy consumption (cooling + heating) is considered, it is calculated that the east and west sides have the biggest total effect and the northern wall has the smallest total effect. When low emissivity glass is used instead of double layer glass, in terms of energy consumption the building side order of effect remains the same, although actual values differ. It is therefore clear that using energy analysis programs to analyse different factors within the energy consumption of buildings will be beneficial in creating energy efficient solutions. This can be carried out in the earlier stages of the architectural design of the buildings or at the renovation stages of existing buildings.Article Citation - WoS: 7Investigation of Educational Buildings in Terms of Daylighting Performance(Yıldız Teknik Üniversitesi, 2011) Kazanasmaz, Zehra Tuğçe; Aral, Duygu; Kazanasmaz, Tugce; 02.02. Department of Architecture; 02. Faculty of Architecture; 01. Izmir Institute of TechnologyEducational buildings have the priority among other building types in daylight performance studies. There are several reasons for this. Classrooms which are used during the whole day should have sufficient and homogeneously distributed daylight. In insufficient daylight conditions, the use of electrical lighting increases energy consumption. Users' visual comfort should also be assured, and design incorporating natural light requires the analysis of sun protection devices in order to avoid glare and excessive heat. Also, atriums and skylights can be included in the building design with the aim of distributing light equally and in a relatively balanced manner throughout the building. However, lighting schemes are often proposed by architects and professionals who tend to make use of different design tools, and it would be pertinent to investigate whether these tools perform as desired. This study analyses daylight design principles and design elements in educational buildings. It outlines the method which has been used to analyse the daylight performance of buildings. A university building was selected for the field study. Measurements were taken in sample spaces to determine daylight performance. Utilising comparison between standard values and measured values, findings are presented in the form of tables, drawings and figures.Article A Fuzzy Logic Model To Classify Design Efficiency of Nursing Unit Floors(Yıldız Teknik Üniversitesi, 2010) Kazanasmaz, Zehra Tuğçe; Tayfur, Gökmen; 02.02. Department of Architecture; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology; 02. Faculty of ArchitectureThis study was conducted to determine classifications for the planimetric design efficiency of certain public hospitals by developing a fuzzy logic algorithm. Utilizing primary areas and circulation areas from nursing unit floor plans, the study employed triangular membership functions for the fuzzy subsets. The input variables of primary areas per bed and circulation areas per bed were fuzzified in this model. The relationship between input variables and output variable of design efficiency were displayed as a result of fuzzy rules. To test existing nursing unit floors, efficiency output values were obtained and efficiency classes were constructed by this model in accordance with general norms, guidelines and previous studies. The classification of efficiency resulted from the comparison of hospitals.Article Citation - WoS: 2The Development of Western-Type Large-Scale Consumption Areas in Turkey and Legal and Structural Regulation Efforts in Urban Retail Environments(Yıldız Teknik Üniversitesi, 2009) Kompil, Mert; Celik, Murat; 01. Izmir Institute of TechnologyThe retail sector has been experiencing a rapid and continuous change worldwide. There have also been profound changes in Turkey, especially after the 1980s. Both the retail sector and the urban retail environments have been altered radically. One of the most significant indicators of this change is the proliferation of western-type large-scale retail developments. Past experiences in developed countries have shown that the uncontrolled development of large-scale retail areas results in some undesired socioeconomic and physical outcomes, such as decline in the cultural and commercial activities of city centers, damage in existing retail workforce structure, and change in local retail hierarchy, nearby land uses, traffic loads and original architectural identity. Many countries have put into practice restrictive and regulatory policies to prevent these negative effects. As similar transformations have also been realized in Turkish retail environments, many institutions think that similar legal regulations must be implemented in Turkey as well. The present study investigates the ongoing retail change within the Turkish context, explores the legal and structural regulatory policies of the Organization for Economic Co-operation and Development (OECD) countries, and critically discusses the appropriate retail regulation policies for Turkey.Article Efficient Design of Nursing Unit Floors(Yıldız Teknik Üniversitesi, 2009) Kazanasmaz, Zehra Tuğçe; Duzgunes, Arda; 02.02. Department of Architecture; 02. Faculty of Architecture; 01. Izmir Institute of TechnologyHospital designs aim to obtain the lowest possible construction, maintenance and operational costs together with patient satisfaction, comfort and privacy. To satisfy these needs, the efficient design of nursing unit areas becomes considerably important. This study was thus conducted to analyze planimetric design efficiency of nursing unit floors by defining certain floor areas and floor area ratios. To test existing nursing unit floors, quantitative assessments were noted in regard to their planimetric efficiency: the utility value of the built floor area, both in terms of its allocation to patient space (served), support (serving) and circulation space and the relative proportions of these. Results were presented in a comparative table. Of the 15 hospital floor plans analyzed, five satisfied minimum space requirements for patient areas, while another five were in the optimum range for circulation areas. Two were defined as the least efficient, having the lowest patient-to-circulation area ratio.Article Citation - WoS: 3Geometric and Kinematic Analysis of Deployable Doubly Ruled Hyperboloids(Yıldız Teknik Üniversitesi, 2017) Maden, Feray; Korkmaz, Koray; Korkmaz, Koray; 02.02. Department of Architecture; 02. Faculty of Architecture; 01. Izmir Institute of TechnologyThis paper aims to develop deployable doubly ruled hyperboloid surfaces that can be used in architectural applications. First, the study systematically analyzes the geometric principles of hyperboloids generated by the ruled surface generation method and examines the morphology to generate different types of hyperboloids. Then, a method is introduced to construct deployable doubly ruled hyperboloid surfaces. The study demonstrates that deployment behavior of the hyperboloid is directly related to joint types used at the intersection points of the bars. Based on kinematic analysis, the study establishes that deployable hyperboloids with a single degree of freedom can be constructed only by revolute and spherical joints. Finally, various hyperboloids having different number of intersections are constructed according to the proposed joint types and their deployment capabilities are discussed.