Applied Mechanics and Materials Vols. 465-466

Abstract: s :This paper reviews of some applications of optical visualization system to compute the fuel-air mixing process during early stage of mixture formation and late injection in Diesel Combustion Engine. This review has shown that the mixture formation is controlled by the characteristics of the injection systems, the nature of the air swirl and turbulence in thecylinder, and spray characteristics. Few experimental works have been investigated and found that the effects of injection pressure and swirl ratio have a great effect on the mixture formation then affects to the flame development and combustion characteristics.This paper presents the significance of spray and combustion study with optical techniques access rapid compression machine that have been reported by previous researchers. Experimental results are presentedin order to provide in depth knowledge as assistance to readers interested in this research area. Analysis of flame motion and flame intensity in the combustion chamber was performed using high speed direct photographs and image analysis technique. The application of these methods to the investigation of diesel sprays highlights mechanisms which provide a better understanding of spray and combustion characteristics.

Abstract: The present study considered the design improvement of Savonius rotor, in order to increase the efficiency of output power. An investigation was conducted to study the effect of geometrical configuration on the performance of the rotor in terms of coefficient of torque, coefficient of power and power output. Modification of conventional geometry has been designed by combining the effect of number of blades and shielding method. CFD simulation was conducted to analyze the flow characteristic and calculate the torque coefficient of all the rotor configurations. The continuity and Reynolds Averaged Navier-Stokes (RANS) equations and realizable k-ε epsilon turbulence model are numerically solved by commercial software Ansys-Fluent 14.0. The results obtained by transient and steady method for the conventional two bladed Savonius rotor are in agreement with those obtained experimentally by other authors and this indicates that the methods can be successfully applied for such analysis. The modified 3 and 4 bladed rotors with hybrid shielding method gave the highest maximum power coefficient which 0.37 at TSR 0.5 and output power exceed 4 watts with rotor dimensions of 0.2m width and 0.2m height. This blade configuration also is the best configuration by several percentages compared to the other model from the previous study

Abstract: Overview on National Renewable Energy Policy and Action Plan of Malaysia is presented. Highlights and updates on the matter are discussed, focusing more towards increasing the awareness on progress of renewable energy sector in Malaysia. The present progress indicates a bright future ahead for renewable energy sector but yet a apposite monitoring on its progress is essential to ensure growth in all available renewable energy resources.

Abstract: In order to encourage students or staff using the walkways as pedestrian and cycling as a mode of trip made inside the campus, the design and layout of the walkway should be improved in the first place. This study will discussed about the existing spatial planning of pedestrian and cycling ways. It will also researches the spatial planning of the walkways with trees and other landscape amenities, examining the obstacles, study on the potential demand for pedestrian and cycling purposes. Within this research a preliminary result on existing pathways inside UTHM as a case study will be exhibited. A survey will be carried out on various parameters and the data collected will be demonstrated at the end of the study. Finally it is hoped that this study will lead to the development of a guideline in designing a functional pedestrian way within a campus where critical parameters such as safety and comfort will be prioritize.

Abstract: This present study discusses the effects of preheated biodiesel and its blends on the performance and emissions of diesel engines. Limited supply of fossil fuel makes biodiesel as one of the major solution for this current situation. However, in using biodiesel and its blends as fuel had created few problems such as poor fuel droplet formation and atomization that consequently result on lots of carbon formation deposit on the valves and injector choking. These problems occur due to the effect of higher viscosity of the biodiesel and its blends itself. This paper reviews the recent research on the effects of preheated biodiesel on viscosity and thus influences to the performance and emissions. Generally there are four methods to lower the viscosity that are heating, blending, micro-emulsification and transesterification. Heating is the easiest solution to bring lower the viscosity. Biodiesel and its blends were heated up before combustion process and most of the researcher reported that the brake power was lower than diesel fuel but higher than unheated biodiesel while the BSFC was found to be higher than diesel fuel and unheated biodiesel. In addition, it observed that the NO_x emission was higher than that of diesel fuel and unheated biodiesel.

Abstract: Diesel engines are still widely needed and applicable to agriculture, construction, light duty passenger car and heavy duty vehicles. In recent years, limited supply of fossil fuel makes alternative sources of fuel especially biodiesel receiving a lot of attention in the automotive industry. However, in using biodiesel as fuel had created poor fuel-air mixing that generally will produce lower performance and higher emissions than diesel fuel. This phenomenon associated with the fuel properties especially viscosity that higher compared to diesel fuel. The aim of this study is to investigate the effects of preheated biodiesel derived from crude palm oil with 5% blending ratio (B5) at 40°C, 50°C and 60°C on performance and emissions of diesel engine under two different load conditions, which are 50% load and 100% load. A four-cylinder four strokes cycle, water cooled, direct injection engine was used for the experiments and the engine speed was varied from 1500 rpm up to 3000 rpm with the 500 rpm increment. Dynapack chassis dynamometer was used to perform the performance data while Autocheck gas/smoke analyzer and Drager were used to obtain the emissions data. Increased of load and biodiesel fuel temperature promotes more rapid engine performance but exhibit relatively small variations in emissions production.

Abstract: This paper reviews the effects of premix fluids between biodiesel, air, and water for external combustion especially open burner. During burning process, biodiesel combustion involves the fuel-air mixing characteristic such as oxidation stability, stoichiometric point, bio-fuel composition, antioxidants and viscosity that influences more NOx emissions than diesel fuel. The strategies to reduce NOx emission are acquired with water additional in biodiesel fuel mixing during early stage of burning process. The method to mix biodiesel-water with injector was acquired in burner system. A vast majority of author reported that the variation in mixing of blending biodiesel ratio and water was found to enhance the burning process and mixture formation thus predominantly reducing the NOx emissions.

Abstract: Today, global warming is the biggest issues due the increasing of emissions from diesel fuel in transportation and manufacturing sectors [1-. The solution for this issue is by using Biodiesel fuel as alternative fuel in both sectors. Malaysia government has introduced the Biodiesel (B5) in the diesel engine for transportations [3]. Biodiesel fuel (BDF) in alternative fuel and renewable energy but it has low quality of fuel and can reduce the performance compared to the diesel fuel (DF)[4-6].

Abstract: In the present study, the efficiency of an evacuated-tube solar collector was investigated experimentally by using water and water-based titanium oxide nanofluids as the working fluids. The titanium oxide nanofluids with the average nanoparticles size between 30-50nm were prepared and tested at volume concentration of 1.0%, 2.0% and 3.0%. The volume flow rate of the working fluids in the solar collector varied from 2.0 to 3.0 liter/min. The experiments were performed at outdoor conditions according to the ASHRAE standard 93-2000. The result shows the efficiency of evacuated solar collector have increased up to 42.5% by using 2.0% concentration nanofluids compared to its base fluid at 2.0litre/min flow rate. In conclusion, the efficiency of collector shows greater enhancement at the low volume flow rate and concentration of nanofluids compared to its base fluid which was water.

Abstract: Biodiesel based on vegetable oils offer the advantage being a sustainable and environmentally attractive alternative to conventional petroleum based fuel. Biodiesel is produced from any fat or oil such as soybean oil, through a refinery process called transesterification. The key issue in using vegetable oil-based fuels is oxidation stability, stoichiometric point, bio-fuel composition, antioxidants on the degradation and much oxygen with comparing to diesel gas oil. Biodiesel can be used as a pure fuel or blended with petroleum in any percentage but the standard storage and handling procedures used for biodiesel are the main issue due to the biodiesel fuel specifications. In the quest for fulfill the industry specifications standard; the fuel should be stored in a clean, dry and dark environment. In this research, three different storage temperature were study which are; low (0 5 °C), ambient, and high (40 50 °C). The key parameters that are required to store biodiesel are discussed, and the recent research advances are noted. Five types of biodiesel after storage all the samples for 2016 hours were tested plus with two product of combustion. Images analysis for combustion process was used to image appearances analysis. Under 2016 hours of storage duration, the effect of degradation was happen although the effect is not significance because the changes are still in acceptable ranges.