تتسم المروحة الهوائية من النوع المعروف بإسم Darrieus بمميزات من بينها البساطة في تصميم الدوار و موقع المُولِّد فضلا عن البساطة في تصميم أي منظومة تحكم تحتاجها. و حيث أن الدوار يعتبر المسؤول الرئيس على إستخلاص طاقة الحركة الكامنة في الريح، عليه فإنه من المنتظر بكل تأكيد أن يكون لخصائص الشكل الهندسي لهذا الدوار أثر ملحوظ على أدائه و بالتالي على أداء المروحة بوجه عام. وقد تم في إطار هذه الرسالة دراسة تأثير خصائص الشكل التالية: عدد ريش الدوار، نسبة وتر الريشة إلى نصف قطر الدوار، نسبة الصلادة، و نسبة إرتفاع الدوار إلى قطره. كما تم أيضا دراسة تأثير قيمة رقم رينولدز على أداء الدوار. أسِّست الدراسة على إستخدام نموذج رياضي يدعى "Multiple Streamtube" و مقطع ريشة من نوع "NACA0012" كما أعدت النتائج النهائية في هيئة مخططات بيانية توضح كلا من معامل العزم و معامل القدرة كدالة فيما يسمى بالسرعة الطرفية النسبية. Abstract Darrieus wind turbines offer a number of advantages such as simplicity of design of structure, generator, and any control system. With the rotor being the direct means of extracting kinetic energy from the wind, its particular geometry must undoubtedly have a great effect on the overall performance of the turbine. The rotor geometrical parameters investigated in this study were: number of blades, chord to radius ratio, solidity, height to radius ratio. Moreover, the effects of Reynolds number were also included. The analysis was based on the use of a multi streamtube model and NACA0012 rotor-blade profile. Results are presented in the form of power and torque coefficients as functions of tip-speed ratio.
هشام إبراهيم أبوسنوقة (2010)

Abstract The contribution of this thesis is to improve the understanding of flame dynamics in the gas turbine combustor. The dynamic of diffusion flame or the flicker of a flame, as they are called in the research community is an important physical parameter associated with the characteristics of a combustion process. The flicker frequency of a flame reflects its oscillation of radiation, pressure and other characteristics, and plays an important role in flame structure, radiation field and energy efficiency. In addition, flickering frequency could be an indication of flame instability. It is therefore important to be able to measure the flicker of a flame in order to achieve an in depth understanding of the fundamental aspects of combustion processes and to develop a technique suitable for advanced flame monitoring in electrical power generation, gas turbine, boiler, and etc... To understand the phenomena related to thermoacoustic, a simple Rijke-type tube combustor was built and studied. Extensive experimental results, as well as theoretical analyses related to the Rijke tube is presented in this project. The results, attributable to both the analyses and the experiments, help explain all the phenomena affecting the acoustic pressure in the combustor. The conclusion is that there are three separate yet related physical processes affecting the acoustic pressure in the tube. To understand this parameter, a simple system was built and studied. Extensive experimental results are presented in this project to measure a flicker signal. In order to begin to understand what flicker parameter is, it was necessary to collect and analyze the light signal produced by light cell from burner which operates on diffusion flame, the chosen method for data collection was a light data acquisition system, the acquired light signal was then analyzed with Lab VIEW software, the software’s main feature is that it was capable of defining the light signal in many parameters, the most important of which were: power spectrum, cross correlation and the light wave shape. The power spectrum gave a concise presentation of the main frequencies which constituted the flicker signals, and their relative amplitudes. this was very helpful in determining the frequency of the diffusion flame (flicker signal).flame height and flame lift off also have been studied in this project. Finally applied this technique and all this Procedures at alkhoms power plant gas turbine combustor and then we compare the results with other technique like CCD camera and Photomultiplier we option the same results with cheaper devices
محمد عمران محمد (2013)

Abstract This study is to develop the specifications of the present cement products so as to comply with the quality and quantities requirements of the local market. The subject of this thesis is to present the results of a series of laboratory trials on a number of raw material mixtures prepared to produce moderate and high sulfate resistance cement at EL- Mergheb cement factory which currently produces ordinary Portland cement. At first, six different raw material sample mixtures were prepared from marlstone,marl and iron ore. The clinker (cement ) produced from these samples was within the moderate sulfate resistance cement ( MSRC ) specifications which mainly requires the tri calcium aluminate (C3A) to be less than 8 % by weight. The trial runs on other three raw material samples made that from mixing marlstone , clay , and iron ore produced clinker specifications that were out of those for MSRC namely, C3A is greater than 8 % . This means that the addition of clay to the raw mix prevents the production of cement with MSRC specifications. This was due to the high percentage of Al2O3 in the clay . The specifications of the clinker products based on these results , MSRC was successfully produced at the factory from raw material mixtures ( marlstone, marl and iron ore ) without any clay addition . Finally three raw mix samples were prepared from marlstone, marl, iron ore, and sand and tested in the laboratory to explore the possibility of producing high sulfate resistance cement ( HSRC) which requires C3A to be less than 5 % . The results of these laboratory trials showed that when the sand in the raw mix is kept under 1.80 % , the produced clinker specifications are within those of HSRC. The permission to carry out these trials in the factory is underway. The expected economic benefits from producing both MSRC and HSRC is highly feasible. Both types will be sold in local market without any additional operating or capital costs .
صالح محمد صالح (2013)