N. M. S. Hassan

Effect of butanol additive on the performance and emission of Australian macadamia biodiesel fuel in a diesel engine

The aim of this paper is to investigate the effect of 5% butanol with biodiesel-diesel blends on the performance, emission, and combustion of a naturally aspirated multi-cylinder diesel engine at different engine speeds and full load conditions. Three types of local Australian biodiesel namely macadamia biodiesel (MB) were used for this study, and the data was compared with conventional diesel fuel (B0). Performance results showed that the addition of butanol with diesel-biodiesel blends slightly lowers the brake power (BP), increases brake specific fuel consumption (BSFC) and brake specific energy consumption (BSEC). The emission study revealed that the addition of butanol additive with diesel-biodiesel blends reduces carbon monoxides (CO), nitrogen oxides (NOx), particulate matter (PM) emission than macadamia-diesel blends and diesel (B0) fuel. Finally, 5% butanol can be added to local Australian biodiesel-diesel blends to lower the NOx and PM emission.

An experimental investigation of bubble rise characteristics in a crystal suspended non-Newtonian fluid

An experimental study of the bubble rise characteristics in non‐Newtonian fluid with crystal suspension is presented in this paper. The suspension was made of different concentration of xanthan gum solutions with 0.23 mm polystyrene crystal particle. Different percentage of crystal content (by weight) was used to vary rheological properties. The effect of crystal particles and bubble volumes on the bubble rise velocity and bubble trajectory is analysed. The results show that the average bubble velocity increases with the increase in bubble volume for crystal suspended xanthan gum solution. In trajectory analysis, it is seen that the small bubbles experienced less horizontal motion in crystal suspended xanthan gum solution while larger bubbles followed a spiral motion. Experimentally determined data for the drag coefficient at high Reynolds number are compared with the results of other analytical and experimental studies available in the literature. The reported experimental data of drag co‐efficient incre...

Performance evaluation of hybrid earth pipe cooling with horizontal piping system

Earth pipe cooling technology is a building design approach for cooling a room in a passive process without using any customary units. It can reduce energy consumption of the buildings for hot and humid subtropical zones. This chapter investigates the performance of horizontal earth pipe cooling (HEPC) in combination with a green roof system. To measure the performance, a thermal model was developed using Fluent in ANSYS 15.0. Data were collected from three air-conditioning modeled rooms installed at Central Queensland University, Rockhampton, Australia. One of the rooms was connected to a HEPC system, the second to a green roof system, and the third standard room had no cooling system. The effect of air temperature, air velocity, and relative humidity of the hybrid earth pipe cooling performance were assessed. A temperature reduction of 4.26°C is predicted for a combined HEPC and green roof system compared to the standard room, which will assist the inhabitants to achieve thermal comfort and save energy in the buildings.

Gaseous and Particle Emissions from a Compression Ignition Engine Fueled with Biodiesel–Diesel Blends

This chapter investigates the sustainability of rice bran biodiesel from environmental point of view. In this study, 5 and 20% biodiesel was tested in a naturally aspirated four-stroke multi-cylinder diesel engine at different load and speed conditions. It was found that all biodiesel blended fuel reduces the brake power (BP) and increases brake specific fuel consumption (BSFC) slightly than diesel fuel. Engine emission results indicated that blended fuel reduces the average particulate matter (PM), carbon monoxide (CO), and hydrocarbons (HC) except nitric oxides (NO) emissions than diesel fuel. Finally, it can be concluded that up to 20% rice bran biodiesel could replace diesel fuel to help in controlling the air pollution to a great extent without sacrificing engine power significantly.

Numerical Modeling of Vertical Earth Pipe Cooling System for Hot and Humid Subtropical Climate

Energy crisis is one of the major problems facing the progress of human society. There are several energy-efficient technologies that can be applied to save energy and make a sustainable environment. Passive air cooling of earth pipe cooling technology is one of them to reduce the energy consumption for hot and humid subtropical climates. The technology works with a long buried pipe with one end for intake air and the other end for providing air cooled by soil to the desired space such as residential, agricultural, or industrial buildings. It can be an attractive economical alternative to conventional cooling since there are no compressors or any customary mechanical unit. This chapter reports the performance of a vertical earth pipe cooling system for a hot and humid subtropical climatic zone in Queensland, Australia. A series of buried pipes were installed in vertical arrangement in order to increase earth pipe cooling performance. To measure the performance of the system, a numerical model was developed and simulated using the CFD software Fluent in ANSYS 15.0. Data were collected from two modeled rooms built from two shipping containers and installed at the Sustainable Precinct at Central Queensland University, Rockhampton, Australia. The impact of air temperature and velocity on room cooling performance has also been assessed. A temperature reduction of 1.82 °C was observed in the room connected to the vertical earth pipe cooling system, which will save the energy cost for thermal cooling in buildings.

Modelling of air bubble rising in water and polymeric solution

This study investigates a Computational Fluid Dynamics (CFD) model for a single air bubble rising in water and xanthan gum solution. The bubble rise characteristics through the stagnant water and 0.05% xanthan gum solution in a vertical cylindrical column is modelled using the CFD code Fluent. Single air bubble rise dispersed into the continuous liquid phase has been considered and modelled for two different bubble sizes. Bubble velocity and vorticity magnitudes were captured through a surface‐tracking technique i.e. Volume of Fluid (VOF) method by solving a single set of momentum equations and tracking the volume fraction of each fluid throughout the domain. The simulated results of the bubble flow contours at two different heights of the cylindrical column were validated by the experimental results and literature data. The model developed is capable of predicting the entire flow characteristics of different sizes of bubble inside the liquid column.

Performance Assessment of an Electrostatic Precipitator of a Coal-Fired Power Plant—A Case Study for Collecting Smaller Particles

Producing sustainable clean energy is one of the key challenges in modern power generation systems. Coal-fired power plants are one of the main sources of electrical energy due to the low cost of coal compared to other fossil fuels. However, one of the major problems of the coal-fired power plant is the exhaust emission of fine particulate matter. Most of the coal power plants and other process industries generally use electrostatic precipitators (ESPs) because of their effectiveness and reliability in controlling particulate matter. The dust particles from the flue gas are separated using flow dynamics and an electrical force induced by the ESP. Baffles and plates are used to obstruct the flue gas flow and to increase residence time to force particle deposition. ESPs are the most reliable control devices to capture the fine particles and their efficiency is also high. However, the precipitator has some serious limitations when capturing smaller size dust particles, especially those less than 2.5 micron. Another drawback is the collection of dust from low-temperature flue gas. In this chapter, a computational fluid dynamics (CFD) model of flow distribution inside the ESP has been discussed which can be useful for collecting smaller particles regardless of operating temperature. A case study is presented showing a wide variety of flow simulation by inserting different shapes of baffles inside the ESP and their effect on particle collection. The collection efficiency of the particles affected by different flow distributions and the possible modifications in the existing ESPs used in the power plants are also discussed.

Assessment of Physical, Chemical, and Tribological Properties of Different Biodiesel Fuels

Abstract Fuel properties of biodiesels are influenced by the physical features of the fatty acid composition, such as the degree of unsaturation, the percentage of saturated fatty acid, monounsaturated fatty acid, and polyunsaturated fatty acid. Fuel properties are the key factors in determining the suitability of any fuel as an alternative fuel. In this study, biodiesels from five different feedstocks have been characterized for their physical and chemical properties. Gas chromatography has been carried out to find out the ester composition of these five biodiesels, and correlation between composition and fuel properties of these five biodiesels have been developed. Fuel properties were measured according to standard procedure ASTM D6751 and EN 14214 and estimated based on the previously published correlation. Also, the quality of these biodiesels was assessed and compared with commercially available biodiesels through multivariate data analysis using PROMETHEE-GAIA software. In the last part, wear and friction of selected biodiesel fuels have been studied and compared with diesel fuel. The result shows that the properties of produced biodiesel are within the acceptable limit of ASTM and EN standards. Highly linear correlations were found between the composition and cetane number, iodine value, oxidation stability, and cold flow plugging point with the regression value of 0.9965, 0.9983, 0.7044, and 0.9985, respectively. Overall, this study found that, among the biodiesels studied, the palm biodiesel was the most suitable alternative followed by the macadamia, moringa, and jatropha, and beauty leaf biodiesel.

Thermal efficiency modeling in a subtropical data center

This chapter presents a study on examining and improving thermal efficiency of a data center. It reports the development of a computational fluid dynamics (CFD) model for the performance analysis of computer room air conditioners, detailed rack-by-rack inlet and exit temperatures and 3D thermal mapping of the data center and racks. In particular, the model identified the potential high-temperature zone within the computer rack and provided a detailed 3D analysis of how cold air moved through the data center. The study determined the impact on cooling resources such as equipment layout, air flow rate, floor tiles, heat load distribution, and other supplementary cooling strategies. It also proposed temperature estimates for given rack loadings. The developed CFD model can be used to develop cooling strategies for achieving better thermal performance in data centers.

Integrated model of horizontal earth pipe cooling system for a hot humid climate

Energy efficiency of a building has become a major requirement since the building sector produces 40%–50% of the global greenhouse gas emissions. This can be achieved by improving building’s performance through energy savings, by adopting energy-efficient technologies and by reducing CO2 emissions. There exist several technologies with less or no environmental impact that can be used to reduce energy consumption of the buildings. Earth pipe cooling system is one of them, which works with a long buried pipe with one end for intaking air and the other end for providing air cooled by soil to the building. It is an approach for cooling a room in a passive process without using any habitual mechanical unit. The paper investigates the thermal performance of a horizontal earth pipe cooling system in a hot and humid subtropical climatic zone in Queensland, Australia. An integrated numerical model for the horizontal earth pipe cooling system and the room (or building) was developed using ANSYS Fluent to measure the thermal performance of the system. The impact of air temperature, soil temperature, air velocity and relative humidity on room cooling performance has also been assessed. As the soil temperature was below the outdoor minimum temperature during the peak warming hours of the day, it worked as an effective heat sink to cool the room. Both experimental and numerical results showed a temperature reduction of 1.11 °C in the room utilizing horizontal earth pipe cooling system which will assist to save the energy cost in the buildings.