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Master Thesis Tek Silindirli Hbo Motorun Performans Gelişimi(2020) Fendal, Metin; Jafarı, RahımThe development of 2 and 4 stroke cycle prototype spark ignition engines using gasoline, manufactured by Minisan A.Ş., is intended in this study. The engines, designed to operate with carburetors and conventional ignition system, functioned successfully. The first designed engine was manufactured with a similar cylinder head, valve configuration, spark plug location and equal cylinder diameter and piston stroke with the ACME model engine, for comparison. The geometry of the connecting rod was altered. The center of the crankshaft shifted approximately 40 – 70 mm from the center of the cylinder. The specific fuel consumption of the new engine was lower and a decision was made to develop it. After the first 340 cc prototype, 2 cylinder, air and water cooled prototype engines were manufactured. A 340 cc engine was also developed within the scope of this thesis. Appropriate combustion chamber geometry and valve configuration for the thermodynamic cycle of these engines were not included in this study. Within the scope of the thesis, commercial electronic fuel injection and ignition systems were acquired and adapted to the engines. These systems were operated by electronic control units (ECU) which were acquired. Theoretical simulation and experimental performance and mapping work were done on the engines for programming the ECU. Two dimensional tables were constructed for the injectors and igniton systems to follow according to the working modes of the engines and were uploaded to the ECU's. Performance tests were conducted with the iv upgraded electronic injection and ignition system of the engines. In comparison to the operation of the engines with carburetors and conventional ignition system, for same engine speed ranges and loads up to 20 percent increase was observed for the excess air coefficient and up to 30 percent decrease was observed for the brake specific fuel consumption. Keywords: Internal combustion engine, ignition system, performance evaluation tests.Doctoral Thesis Aşırı Kalabalık Alanların Enerji Performansının İyileştirilmesi için Termal Konfor, Iaq Endeksleri ve Termal Enerji Depolamasının Deneysel Değerlendirmesi ve Çalışması(2022) Al-malakı, Fadhıl Asaad Mohammed Kadhım; Jafarı, Rahım; Al-saedi, Hasanen M.In 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.Master Thesis Otomobil Fren Diskinin Termal Performansının Ölçülmesi(2023) Erkılıç, Kaan Tamer; Jafarı, RahımHızlanma bir araç için çok önemli bir dinamiktir, ancak yavaşlama araç güvenliği için kilit unsurdur. Fren sistemi otomobili yavaşlatacak veya durduracak en önemli ekipmandır. Bir fren sisteminin işlevi, disk ve balatanın sürtünmesi ile gerçekleşir. İçerdiği komponentlerin tasarım ve test adımlarında ısıl performansları hassas bir şekilde ölçülmeli ve komponentin çalışma koşulları altında gereken performansı göstermesi gerekmektedir. Bu çalışmada, fren disklerinin hem aerodinamik hem de termal karakteristiklerinin gözlemleneceği bir deney düzeneği tasarlanmış ve üretilmiştir. Deney düzeneği üzerindeki disk, balata, jant ve lastik gibi parçalar tipik bir binek otomobilde kullanılanlar ile birebir aynıdır. Komponentlerle birlikte binek bir otomobilin çeyrek ağırlığı deney düzeneğine silindirik ağırlıklar yardımıyla şaft üzerine uyarlanmıştır. Bunun yanında, deney düzeneğinde tekrarlamalı fren senaryosu kullanılmış olup frenlemenin aerodinamik ve termal çıktılarının ayrıntılı numerik modeller kullanılarak simülasyonları gerçekleştirilmiştir. Gerçekleştirilen deneyler ve simülasyonlarda, otomobilin hızı sebebiyle oluşan hava akışının jant içerisinde yavaşladığı ve buna rağmen jant içerisinde türbülanslı bir hava akışı olduğu gözlemlendi. Termal simülasyonlar ve deneyler sonucunda ise fren diski üzerindeki sıcaklık dağılımı gözlemlenmiş olup fren diskinin balata ile temas ettiği alanın temas alanının tam karşısındaki alanın sıcaklığına göre daha yüksek olduğu ve sıcaklığın eşit dağılmadığı tahmin edilmiştir.