Department of Modeling and Design Engineering Systems
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Browsing Department of Modeling and Design Engineering Systems by Subject "mechanical engineering"
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Item AN ICE ACCRETION PREDICTION TOOL FOR AIRFOILS BASED ON OPENFOAM(2022-02-15) Edeeb, Seghaer Hossein; Akay, Hasan U.; Özgen, SerkanIce accretion on aircraft components degrades the aircraft performance and causes se rious flight problems. Flight tests, icing wind tunnels, and commercial packages are the main tools used to predict ice shapes and thicknesses. Although there are some commercial and institutional ice accretion simulation packages such as LEWISE, ON ERA, FENSAP, CIRA and CANICE available in the literature, there is no major ice accretion simulation package available in the open-source community. In this thesis, open-source software are used and modified for simulating ice accretion process and its effect on the aircraft characteristics. OpenFoam solver simpleFoam is used for solving the viscous turbulent fluid flow around an airfoil and the Lagrangian solver icoUncoupledKinematicParcelFoam for solving the trajectory of supercooled water droplets. To solve the governing equations of the phase-change, a transient solver called THERMSOLVICE is developed using the Octave library. Ice accretion algorithm is created by combining the available OpenFOAM solvers and the developed THERMSOLVICE solver. It is believed that this approach has the potential for improving the state of the art in prediction of ice formation on aircraft components as more researchers work on it. The created package is used to predict rime and glaze ice shapes and thicknesses on a wing airfoil for different icing condition cases. The effects of ice formation on the airfoil lift and drag coefficients are also investigated, showing significant changes in certain cases. The results show a satisfactory agreement in ice shape predictions obtained using the developed package with the corresponding data in the literature.Item ELASTIC ANALYSIS OF POLAR ORTHOTROPIC FUNCTIONALLY GRADED ROTATING ANNULAR DISKS(2015-01-30) ESSA, Saad; ARGEŞO, Ahmet HakanSemi-analytical and analytical solutions are presented for polar orthotropic annular functionally graded rotating disks by taking also thickness variation into account. The formulations are performed by referring to polar coordinate system and the material properties are assumed to vary in radial direction. The governing equation of the problems are obtained under the assumptions of plane stress and small deformations. Disks having two types of boundary conditions are considered. The first one is an annular disk having traction free inner and outer surfaces, whereas, the second has a rigid inclusion within and traction free outer surface. Semi-analytical solution is obtained by assuming that elasticity moduli and disk thickness vary according to a nonlinear function in which its shape is controlled by three parameters. Poisson’s ratios are assumed to be constant valued and the variation of density can be described by any form of continuous function. The three parametered nonlinear function is formed by combining the exponential and power forms of variation functions that are widely used in literature for describing material gradation. The analytical solution is determined by considering that the Elasticity moduli, disk thickness and density vary according to power law. Solutions are verified numerically by using a computational method which is based on nonlinear shooting method. Verification examples are given first. Then, parametric analysis that inspects the effects of the degree of orthotropy and material gradation on the elastic responses of rotating disks are presented. In the analysis, elastic limit angular velocities of the disks are evaluated according to Hosford’s criteria.Item EXPERIMENTAL EVALUATION AND CFD STUDY OF THERMAL COMFORT, IAQ INDICES, AND THERMAL ENERGY STORAGE FOR THE IMPROVEMENT OF THE ENERGY PERFORMANCE OF OVERCROWDED AREA(2022-12-11) AL-MALAKI, Fadhil Asaad Mohammed Kadhim; JAFARI, RahimIn recent years, buildings, including prison halls, have contributed significantly to the world's rising energy use, with 34 % of the energy used by these buildings being attributed to cooling and heating. This study examines the use new combination of phase change materials (PCMs) for energy conservation in buildings through thermal storage, including the use of double layers of PCMs paraffin waxes with different properties. The study evaluates the indoor air quality characteristics of two protocols for cooling and heating in four different scenarios that are classified according to the seasons in a location, with a high daily temperature range, similar to that of Iraq. An experimental facility for the study was designed, constructed, and tested at Technology University in Baghdad. The experimental measurements were taken in a small-scale model 1:4 of a prison quarry, with dimensions of 1.2 by 0.6 by 0.8 meters and a side inlet grill. This prototype model was used to investigate the impact of integrating double layers of panels on the roof of the space and their ability to minimize fluctuations, energy usage, and shift peak load. The computational work involved solving the partial differential equation for the conservation of mass, momentum, and energy and its rate of dissipation using the finite volume technique. Modifications to the algorithm were made to simulate the space with and without PCMs in the roof for all scenarios. The majority of the computed data were presented as temperature contours and other thermal contours, and when compared to the experimental results, a reasonable level of agreement was observed. The use of PCMs as latent heat thermal energy storage (LHTES) in the room envelope for passive cooling has gained significant attention due to their ability to store large amounts of energy. The results of this study show that the use of TES can reduce the energy required for the space by 47.2 % in the summer and in varying proportions during other seasons, also when PCMs are used in hot weather, in door temperature drops by 7 °C at average, compared to when they are not used.