Experimental Study of Annulus Flow for Can Combustor with Vibration Influence

ركز هذا البحث على دراسة سلوك مخطط السرعة تحت تأثير الاهتزاز وبترددات مختلفة (34 , 48, 65, 80 هرتز) لكل من الجزء العلوي والسفلي من الجريان الحلقي لغرفة احتراق توربين غازي  نوع العلبة .تم تصميم جهازومنظومة الاهتزاز لتوليد قيم الترددات المذكورة اعلاه وتسليطها على جدار غرفة الاحتراق لدراسة تأثير الاهتزاز على الجريان الحلقي لغرفة الاحتراق.تم جلب غرفة الاحتراق وهي جزء حقيقي من محطة الخيرات الغازية.تم الاختبار لثلاث مناطق في غرفة الاحتراق في كلا الجزئين العلوي والسفلي من الغرفة لأختبار تأثير الاهتزاز على مخطط السرعة وشدة الاضطراب والنتيجة كانت ان الزيادة في التردد تؤدي الى الزيادة في قيم السرع مع نشوء دوامات كبيرة في بعض النقاط, كذلك رقم رينولد يزداد مع زيادة السرعة.وفي النهاية وجد ان الزيادة في مستوى الاهتزاز يسبب او يؤدي الى عدم انتظام مخطط السرع والذي ينتج عنه او يأثر على التوزيع لكفاءة التبريد لغرفة الاحتراق.This paper concentrate on studying the behavior of velocity profile under the influence of different frequency (34, 48, 65 and 80 Hz) in each of the upper and lower annulus of Can Combustor.An experimental rig was designed to simulate the annulus flow inside a Can Combustor.The Can Combustor tested in this study is real part collected from Al-Khairat/Iraq gas turbine power station.The velocity profiles are investigated at three positions in the annular for upper and lower region.The axial velocity and turbulence intensity are calculating with different frequency for upper and lower annulus.The results were shown that the increase of frequency lead to increase the velocity profile and large recirculation zone will build in some points.Reynolds number increasing with raise of axial velocity. Also the increasing in vibration level cause non-uniform velocity profile which affect on distribution of cooling effectiveness

Improving Thermal Efficiency of Internal Combustion Engines: Recent Progress and Remaining Challenges

Improving thermal efficiency and reducing carbon emissions are the permanent themes for internal combustion (IC) engines. In the past decades, various advanced strategies have been proposed to achieve higher efficiency and cleaner combustion with the increasingly stringent fuel economy and emission regulations. This article reviews the recent progress in the improvement of thermal efficiency of IC engines and provides a comprehensive summary of the latest research on thermal efficiency from aspects of thermodynamic cycles, gas exchange systems, advanced combustion strategies, and thermal and energy management. Meanwhile, the remaining challenges in different modules are also discussed. It shows that with the development of advanced technologies, it is highly positive to achieve 55% and even over 60% in effective thermal efficiency for IC engines. However, different technologies such as hybrid thermal cycles, variable intake systems, extreme condition combustion (manifesting low temperature, high pressure, and lean burning), and effective thermal and energy management are suggested to be closely integrated into the whole powertrains with highly developed electrification and intelligence

Improving Thermal Efficiency of Internal Combustion Engines: Recent Progress and Remaining Challenges

Improving thermal efficiency and reducing carbon emissions are the permanent themes for internal combustion (IC) engines. In the past decades, various advanced strategies have been proposed to achieve higher efficiency and cleaner combustion with the increasingly stringent fuel economy and emission regulations. This article reviews the recent progress in the improvement of thermal efficiency of IC engines and provides a comprehensive summary of the latest research on thermal efficiency from aspects of thermodynamic cycles, gas exchange systems, advanced combustion strategies, and thermal and energy management. Meanwhile, the remaining challenges in different modules are also discussed. It shows that with the development of advanced technologies, it is highly positive to achieve 55% and even over 60% in effective thermal efficiency for IC engines. However, different technologies such as hybrid thermal cycles, variable intake systems, extreme condition combustion (manifesting low temperature, high pressure, and lean burning), and effective thermal and energy management are suggested to be closely integrated into the whole powertrains with highly developed electrification and intelligence