Prediction and Investigation Particulate Fillers (Aluminum &Alumina) Effect on the Thermal Conductivity of Polymeric Matrix Composite (Polyester)

The main objective of this paper is to study the thermal conductivity of composite materials and the parameters affecting it, then to determining the validity of the best theoretical model matching with experimental results and to predict thermal conductivity of any composite materials with different particle size. Alumina& aluminum filled thermoset polyester composites are investigated in this study, and their thermal conductivity will be the central focus. Aluminum particle, alumina particle and aluminum fiber (5wt % to 45wt %) were added to polyester matrixes. It was found that both fillers and fiber positively effect on the thermal conductivity of the composite. By using visual basic program, the results show there are three different theoretical models (Maxwell Equation, Lord Rayleigh Equation &Lewis and Nielsen Equation) valid to predict the effective thermal conductivity for reinforced the polyester by Al and Al2O3 powder until 35wt% and 45wt% respectively. In addition, the rule of mixture model is good to predict the effective thermal conductivity (for aluminum fiber parallel with polyester matrix)

The Effect of Ceramic Coating on Performance and Emission of Diesel Engine Operated on Diesel Fuel and Biodiesel Blends

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