In this work, the effect of ceramic coating on performance, exhaust gas temperature and gases emissions of diesel engine operated on diesel fuel and biodiesel blends was investigated. A conventional four stroke, direct injected, single cylinder, diesel engine was tested at constant speed and at different load conditions using diesel fuel and biodiesel blends. The inlet and exhaust valves, the head of piston and cylinder head of the engine were coated by ceramic materials. Ceramic layers were made of (210-240) μm of Al2O3 and (30-60) μm of 4NiCr5Al as a bond coat for inlet and exhaust valves and (350-400) μm of YSZ and (50-100) μm of 4NiCr5Al as a bond coat for head of piston and (280-320) μm of Sic and (40-80) μm of 4NiCr5Al as a bond coat for cylinder head. The coating technique adapted in this work is the flame spray method. The engine with valves, piston and cylinder head ceramic coated research was tested for the same operation conditions of the engine (without coating). The results showed that a reduction in brake specific fuel consumption of 19.29%, 15.91%, 14.65% and 7.06%, an increase in brake thermal efficiency of 23.68%, 19.77%, 16.51% and 6.32%, the increase in exhaust gas temperature of 9.01%, 7.22%, 15.7% and 11.42%, the reduction of CO emission of 18.57%, 20%, 20.5% and 27.77%, the reduction of HC emission of 28.97%, 43.9%, 38.88% and 36.41% for diesel, B5,B10 and B100 respectively.
S Ali…, Journal of Physical Education, 2019 - Cited by 1
Twisted tape insertion in the smooth plain tube is one of the types of passive methods that are used to enhance heat transfer. Swirl fluid flow inside the tube and related heat transfer characteristics are very complex. ANSYS FLUENT (V 16.1) and ASPEN industrial program are used in analyzing this technique for enhancement heat transfer. A circular plain tube has length L=8534mm and 17 mm inner diameter with a twisted tape of twist ratio of y = (H/D) = (150/17) =8.8 along the plain tube were considered for this study. Eight Reynolds numbers (Re) of 784, 1000, 2000, 3000, 4000, 5000, 6000 and 7000 are used to analyze the response of thermal performance. Crude oil API 28 exit temperature, film heat transfer coefficient, Nus
... Show MoreThe research tagged (Perceived Organizational Support in High Performance) deals with identifying the extent of the impact of perceived organizational support as an explanatory variable on high performance as a response variable for the purpose of reaching appropriate mechanisms that enable colleges of the University of Baghdad to exploit the perceived organizational support in achieving the required high performance and pursuit of its goals. The researcher relied on the descriptive and analytical approach in carrying out the research. An intentional sample was selected and reached (70) persons from the higher leadership of the colleges represented by (deans, assistants deans, heads of departments) that r
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The work of this paper is an investigation to improve the condenser performance of the automobile air conditioning system by enhancing the air-side heat transfer from the condenser through the use of an air guide net installed in front of the condenser face which is basically an aluminum plate having a circular entrance shape for the air passage. The A/C system was examined under two types of test. The first test was conducted the air guide net, while the second was done with the air guide net. The performances of the A/C system under these tests were compared. For the second type of test, the experiment was carried out with three different size of air guide net, three different circular diameters (2, 3 and 3.5 cm) a
... Show MoreAbstract
Performance evaluation is of great importance in all countries of the world, because it has a prominent and effective role in determining the efficiency and effectiveness of the optimal use of available resources, which are rare and important in achieving the desired objectives. With the continued growth of public spending and the limited resources, the State seeks to achieve its objectives through its units with minimal expenditure or deficit, rationality and wastefulness in the spending. In many countries, particularly developing countries, reforms are made in the public sector to achieve that goal through the adoption of IPSAS, which is reflected in the developmen
... Show Moreيسعى هذا البحث الى تقديم اطار عملي ونظري حول موضوع "تأثير الاقتصاد المنزلي في تعزيز الاداء العالي" وتم اختبار مخطط الدراسة الفرضي في القطاع التعليمي الحكومي في محافظة البصرة ,ويتضمن عدد من تشكيلات الجامعة التقنية الجنوبية. واستخدمت الاستبانة والمقابلة الشخصية كأسلوب لجمع البيانات للدراسة وكان حجم العينة114 موظف. وقد استخدمت عدد من الاساليب الاحصائية لاختبار فرضيات الدراسة. واظهرت النتائج بأن هناك تأثير ايج
... Show MoreIn the current analysis, the effects of circumferential scratches along the inner surface of a 170ᵒ -arc partial journal bearing has been numerically investigated. Their impact on the thermo-elasto-hydrodynamic performance characteristics, including maximum pressure, temperature, deformation, and stress, has been examined thoroughly. The ANSYS Fluent CFD commercial code was employed to tackle the iterative solution of flow and heat transfer patterns in the fluid film domain. They are then applied to the ANSYS Static Structure solver to compute the deformation and stress resulted in the solid bearing zone. A wide range of operating conditions has been considered, including the eccentricity ratio ( ) and scratch depth (
... Show MoreA.C electrical conductivity and dielectric properties for poly
(vinyl alcohol) (PVA) /poly (ethylene oxide) (PEO) blends undoped
and doped with multi-walled carbon nanotube (MWCNTs) with
different concentrations (1, and 3 wt %) in the frequency range
(25x103 - 5x106 Hz) were investigated. Samples of (PVA/PEO)
blends undoped and doped with MWCNTs were prepared using
casting technique. The electrical conductivity measurements showed
that σA.C is frequency dependent and obey the relation σA.C =Aωs for
undoped and doped blends with 1% MWCNTs, while it is frequency
independent with increases of MWCNTs content to 3%. The
exponent s showed proceeding increase with the increase of PEO
ratio (≥50%) for undope
the behavior of the first-order black and gray solitons propagtedin optical fiber in the presence of frequency chirp is studied analytically and numerically results show that phase profile of black solitons changes abruptly