Determination of Fluid Friction Factor for Nanofluids in Pipes

Nanofluids are explained as suspensions of nanoparticles in conventional heat transfer fluids. Nanofluids possess enhanced thermal conductivity therefore making it desirable for advanced heat transfer applications. Until recently, numerous studies and researches regarding nanofluids are directed towards heat transfer. Therefore, little is known regarding the relationship between nanofluids and how they affect fluid friction factor for flow in pipes. Hence, this study aims to study and determine the parameters responsible for affecting the fluid friction factor in pipes concerning nanofluids. The objectives of this study include studying preparation methods of nanofluids and also to determine the fluid friction factor for three nanofluids at the same concentration. The scope of the study focuses on oxide ceramics and metallic nanoparticles of different densities and viscosity. Firstly, a theory is developed to model the experiment and hence the outcome of the experiment can be predicted whereby fluid friction factor of different nanofluids is dependent on their respective densities. Secondly, nanoparticles dispersed in aqueous solutions are procured and nanofluids are synthesized by dilution with distilled water. The nanofluids are flowed into experimental pipe setup where their respective pressure drops are measured. Further data analysis is conducted to establish and evaluate the fluid friction factor by means of a Moody chart and Colebrook equation. The variable concerned in this study is the density of individual nanoparticles chosen

Effects of ethanol additives on spark ignition engine performance and emissions fuelled with methanol-gasoline blends / Mohamad Qayyum Mohd Tamam

Emissions of greenhouse gases resulting from automobile exhaust emissions is a major concern in recent years due to its effect on climate change. Therefore, an environmentally friendly alternative for fossil fuel needs to be developed to reduce heavy reliance on fossil fuels. Ethanol possesses a great potential to serve as substitute to gasoline due to its favourable physicochemical properties. This research investigated the effects of ethanol additives on spark ignition engine performance and emissions fuelled with methanol-gasoline blends. Four ethanol-methanol-gasoline blends or GEM blends were prepared with variable ethanol concentrations (0%, 5%, 10%, 15%) and constant methanol concentration (10%). Resultant blends were denoted as M10, E5M10, E10M10, and E15M10 in reference to each respective alcohol constituents. Physicochemical properties of these blends were measured in terms of density, calorific value, as well as kinematic viscosity and the results were compared to that of pure gasoline. Results showed that density and kinematic viscosity of ethanol-methanol-gasoline fuel blends increases with ethanol concentration. E15M10 has shown the most improvement in terms of density and kinematic viscosity with 10.7% and 18.7% increase respectively as compared to pure gasoline. In contrast, calorific value was found to decrease as ethanol concentration decreases. E15M10 possesses lowest calorific value with 16.9% decrease as compared to pure gasoline. Engine performance and emissions were carried out on a single-cylinder SI engine at constant speed of 3000 rpm under various engine loads of 1.6, 3.2, and 4.8 Nm. Results showed that generally ethanol-methanol-gasoline fuels possess increased BSFC and BTE on average than pure gasoline. E15M10 displayed highest increment of BSFC at 17.2% average increase with respect to pure gasoline. E10M10 has displayed the highest improvement in BTE with an average of 9.4% increase as compared to gasoline. Meanwhile, no significant variations of EGT were observed. Exhaust emissions indicate that all ethanol-methanol-gasoline blends produced increased CO2 and NOx emissions while CO emissions decreases. E15M10 showed the most reduction in CO emissions with 90.6% decrease compared to pure gasoline while E10M10 has shown the most increased CO2 and NOx emissions with 1.0% and 6.7 times increase respectively. In conclusion, ethanol-methanol-gasoline fuel blends improved engine performance and emissions in terms of BTE and CO emissions in comparison to pure gasoline. Thus, ethanol additives are a practical alternative for blending with methanol-gasoline fuels in lower blend ratios

Comparison of diesel engine performance between a mechanical pump and a common rail fuel injection system equipped with real-time non-surfactant emulsion fuel supply system

The global focus in emulsion fuels is due to the advantages over conventional diesel fuels. It has the capabilities to simultaneously reduce the emissions of NOx and smoke. It also said to reduce the fuel consumption of diesel engine by significant percentages. However, due to the interdependency on surfactant, emulsion fuel does not seem to be possible as alternative fuel in an economic perspective. This is because of the high market price of the commercial surfactant. Therefore, this research focused on non-surfactant W/D that produced by a system known as Real-Time Non-Surfactant Emulsion Fuel Supply System (RTES). RTES has been applied with the goal of investigating the impact on exhaust emissions and fuel consumption of a mechanical pump fuel injection system diesel vehicle (MP) and a common rail fuel injection system diesel vehicle (CR). A one-ton truck represents as MP (Mechanical Pump) and an SUV represent as CR (Common rail) are the test vehicles for the said research. The non-surfactant W/D with 6.5 wt.% of water produced by the RTES used as the test fuel and named as E6.5. It has been emulsified in the RTES right before being injected into the diesel vehicles. The testing was performed on a chassis dynamometer following the West Virginia University 5-peak cycles. The findings show that the utilization of non-surfactant W/D has increased the fuel consumption by 7.39% for MP and 3.2% for CR respectively as compared with base diesel fuel. NOx, smoke emissions and exhaust temperature have significantly reduced by the MP relative to CR vehicles. Overall, the concept of non-surfactant W/D seems to have implementation potential for reducing harmful emissions from both diesel-powered vehicles