Browsing by Author "Sugathapala, T"

Now showing 1 - 8 of 8

item: Thesis-Abstract
Assessment of embedded energy in manufacturing wall tiles using two different firing technologies in Sri Lanka
(3/28/2011) Divakara, SA; Attalage, RA; Sugathapala, T
Energy productivity is a critical factor for the Sri Lankan manufacturing industries which is a critical issue that affects the cost of production. Efficiency in consumption of energy and its conservation would be one of the most important means of energy cost reduction and also for meeting future energy demand. The ceramic industry is one of energy intensive industry in Sri Lanka which uses massive quantity of thermal energy as well as electrical energy for the manufacturing processes. An analysis was carried out to asses the energy consumption of two industrial processes in manufacturing ceramic wall tiles using technologies of conventional and fast firing. Conventional firing technology is the oldest technology and fast firing technology is the latest technology that are being used to fire ceramic products./ The main objective of the study was to analyze the energy efficiency of technologies in a broad view and as secondary to study the energy conservation techniques used and can be used in order to reduce the energy consumption. The method of embedded energy analysis was used to analyze the energy of two processes under certain boundary conditions. Analysis of embedded energy was calculated in three levels such as level I direct energy supplied by the fuels and electricity, level 2 all ancillary energy inputs and level 3, energy in raw materials. The calculated embedded energy of wall tiles manufactured with the technology of conventional firing is 16 GJ/ MT and similarly the embedded energy of wall tiles manufactured with the technology of fast firing is 9 GJ / MT. The energy consumption in each levels, level 1, level 2 and level 3 of conventional firing technology is 96.7%, 2.4 %, and 0.9% respectively and in fast firing technology is 96.5%, 2.4%, 1.1% respectively./ 1'he latest technology of fast firing technology has been developed highly considering of energy efficiency productivity and product quality. The fast firing technology consist of many kinds energy saving technologies such as waste heat recovery, high thermal efficient kiln furniture and refractory, high efficient burners, efficient tile transportation methods. Out of two technologies of fast firing and conventional firing the most energy efficient technology is the fast firing technology which is 12% more efficient than the conventional tiring with compared to the result of the study. Further the implementation of energy conservation techniques to the existing plants will be incorporated to reduce energy consumption by 5 to 10 percent on electrical and 2 to 5 percent on thermal.
item: Conference-Abstract
Barriers in adoption and operation of electric buses into the existing public transit network
(Department of Civil Engineering, University of Moratuwa, 2021-10) Thilakshan, T; Sugathapala, T; Bandara, S; Perera, HLK
Transportation has been identified as a major contributor in terms of increase in air pollution and related impacts resulting in climate change and global warming amongst other threats to the world and people. The nature of transportation related pollution has been caused by increasing motorization along with the absence of targeted policies especially in developing countries and frameworks for cleaner transportation options. Many types of measures to fight transportation related pollution are adopted globally including modal shift towards public transport, electrification, low-carbon fuels and energy vectors, demand management, innovation and upscaling, and improved design, operations and planning of transport systems. Electrification of vehicles has been globally accepted as a transfer of high potential due to the absence of tailpipe emission and the possibility to generate electricity from renewable energy sources has more potential to make electric vehicles cleaner in an overall context. Sustainable transportation mainly comprises of development of public transit and transfer of private vehicle users to public transit modes. It is evident that public transit is one of the most preferred sustainable options in transport but it’s contribution to the overall transport emission scenario is significant at present, especially in developing countries, due to higher model share. The use of cleaner technology in public transport can make a substantial impact on the reduction in emissions. This study concentrates on public bus services and the replacement with or introduction of electric buses which is currently being initiated globally. The adoption of electric buses (e-buses) includes its set of positive outcomes but is a challenge in the initiation and implementation process. The adoption of e-buses is not an easy transition which is impacted by a number of barriers including high initial procurement costs, issues related to charging and related infrastructure development, still relatively new/novel in terms of technology, scarcity of skilled labour, unavailability of data amongst others. The outcome from the study with respect to the barriers and the related mitigation measures to facilitate adoption and operation of electric buses is attained via a comprehensive review of the available sources published including research papers, national/non-governmental reports and relating documents which discuss on the air quality levels especially in the urban context and the contribution of the transport sector to the overall air pollution ratio. This study identifies the barriers, elaborates the reasons behind the barriers and recommends mitigation strategies to accommodate these barriers in the best possible manner to ensure transition to electric buses can be facilitated in a smooth manner with no considerable impacts to any stakeholders. The infrastructure related to electric buses operation is a major part of operating a viable electric bus network. Thus, identifying the stakeholders and the related barriers in adoption and operation of e-buses, development of effective operational strategies and development of an efficient evaluation mechanism are important parts of the e-buses framework considered in this study. The study discusses the identification of the right technology & viable business models, the framework for the development of an optimization model for electric bus operation subject to resource constraints which include planning of routes, 10 development of schedules and charging intervals in compliance with the available infrastructure. Outcomes from the study are expected to facilitate and educate operators of electric buses in the public transit network with the positioning of electric buses in the right framework so that the service can be provided with no disruptions to adoption and operation along with the prime goal of maximizing the expected outcome of the total reduction of emission and promotion of e-buses in an economically viable manner.
item: Conference-Full-text
A computational study of the aerodynamics of plunging and pitching motions of airfoils
(IEEE, 2022-07) De Silva, L; Samaraweera, N; Jayaweera, N; Sugathapala, T; Rathnayake, M; Adhikariwatte, V; Hemachandra, K
Investigation of flow characteristics and force generation of flapping wings have received significant attention in modern fluid dynamics due to emerging applications like bio-inspired Micro Air Vehicles (MAVs) and energy harvesters. In this study, aerodynamic characteristics of NACA 2412 airfoil in plunging and pitching motion are simulated using an incompressible Navier Stokes solver in varying Reynolds and Strouhal numbers. The wake of the airfoil which is visualized using velocity and pressure contour plots and aerodynamic force generation are analyzed. A close agreement is obtained between numerically simulated aerodynamic characteristics including wake structure and forces in this study and experimental results in the literature. The analysis discloses that wing-wake interaction enables a dramatic increment in trust and lift forces up to 300%. Moreover, aerodynamic forces generated in combined pitching and plunging motion show a maximum of 225% increment from the numerical sum of forces in the two sub-motion in some combinations of Reynolds and Strouhal numbers, demonstrating the coupled behaviour of plunging and pitching motions.
item: Conference-Abstract
A data acquisition methodology for the development of local driving cycles
(Department of Civil Engineering, University of Moratuwa, 2020-12) Gajanayake, S; Bandara, S; Sugathapala, T; Perera, HLK
Driving Cycles (DCs), the time speed profiles of a certain vehicle type for a given road segment can be considered as one of the main tools to quantify and to assess the performance in terms of fuel economy and emissions of a given vehicle category. There have been numerous approaches that have been adopted to develop DCs locally, representing various geographical regions of the world. Despite various approaches adopted, the researchers have defined a four-stepped common methodology for DC development viz. Route Selection, Data Acquisition, Cycle Construction and Cycle Assessment. During the study, approaches have opted under each step pertaining to the purpose of the DC development, i.e. for the characterization of fuel economy. Acquisition of data for DC development is one of the most important steps of the procedure since the representativeness of the DC of local driving behaviour depends on the quality of the data collected. Regardless of the approach adopted, the acquired data should be reliable, representative, consistent and homogeneous. The three main approaches that are in practice throughout the world can be listed viz. chase-car method, instrumented-car method and hybrid method. During this study, more focus is concentrated on suggesting a methodology of data collection for DC development. Since local driving behaviour incorporates irregular kinematic patterns integrated with aggressive driving behaviour, the instrumented-car method has opted over the chase-car method. Moreover, the operational complexity and the cost associated with the latter approach is higher than that of the opted method. Furthermore, on par with the introduction of On-Board Diagnostics (OBD) protocol as a worldwide standard for automobiles in the later 1990s, the invention of many OBD data logging devices happened. Consequently, the data logging on an automobile has been made convenient than ever. When it’s funnelled down to the instrumented-car method, the techniques in practice can be listed under two main categories viz. device-based methods and device and app-based methods. In device-based methods, the data are saved in internal storage and then it’ll be transferred for analysis. On the other hand, the device and app-based method facilitate the real-time data to be transferred to the connected app-hosting device viz. a mobile device, tablet or a laptop. In the latter method, the data logging device is connected with the app-hosting device primarily via Bluetooth or WIFI. Car manufacturers have introduced their own OBD data logging devices with internal storage viz. Chrysler DRBIII, Ford New Generation Star Tester, General Motors Tech II, Toyota Diagnostic Tester, Nissan Consult, VAG 551, etc. The said devices have mostly been introduced with the manufacturers’ proprietary technology which has made them costlier. Due to the cost factor in the device-based method, most of the researchers have adopted device and app-based methods which have come up with low-cost alternatives. A dedicated data logging device, ELM-327 adapter has opted for the research study. Due to its lower cost and hence multiple devices can be used for parallel data collection in vehicles. Out of several third-party software applications for OBD data logging, Torque ProTM has been opted for the study mainly due to its feature-rich interface, operational convenience and compatibility with a wider range of vehicle variants. The data is sampled at a frequency of 1 Hz. The logged data onto the app-hosting device is saved in two main types i.e. ‘.csv’ file type and ‘.kml’ file type. The mechanical parameters viz. engine speed and fuel flow rate, the spatial parameters viz. latitude, longitude and altitude have been logged using the said device-app arrangement. During the study, data is planned to collect from two-wheelers (2W), three-wheelers (3W) and four-wheelers (4W). The initial phase of the study would be to analyze the data streams pertaining to 2W, 3W and 4W, then evaluate whether there are significant discrepancies among the driving behaviours and patterns. Then the second phase of data collection would be conducted to develop the local driving cycle. Unlikely in 4W, in 2W and 3W, an OBD port cannot be found in common. Thus, an app-based data acquisition method is recommended for 2W and 3W. With respect to this case, several readily available applications are tested. The major limitations of the applications are that they log data at lower frequencies such as less than 1 Hz and the operational difficulty of obtaining the logged data from the users’ devices since the real-time data logging feature is unavailable in most. Therefore, a locally developed application at the University of Moratuwa which suits the data collection requirements has opted. The sample size has been selected as thirty vehicles from each category, accounting for ninety vehicles altogether in all three types. The geography of data collection has been selected as the urban areas of Colombo City.
item: Thesis-Abstract
Energy storage systems for optimum energy utilization of village hydro schemes in Sri Lanka
(3/28/2011) Athula, JM; Sugathapala, T
Compared to the other countries in the region, Sri Lanka has a deep penetration of approximately 75% of grid electricity. However, providing electricity every rural household is a difficult goal, without employing off-grid technologies. Accordingly, the present 2% of household are receiving off-grid electricity will become 6% by year 2010, according to the prevalent government policy. This requires new technological interventions in the micro hydro sector, as the quality of hydro resources available for exploitation is coming down rapidly./ This study aims at developing a concept of optimum energy storage to explore such meagre hydro resources. The proposed concept takes the advantage of highly developed technologies such as power electronics to offer an energy to energy matching supply. Demand solution as opposed to the orthodox micro hydro technology which is designed to match the evening peak lighting load of a rural village./ The most critical aspect of an energy storage system is the sizing of energy storage. Aspects such as storage capacity, charging time, level of discharge and life cycle of storage play critical roles in designing a system. The proposed system uses the daily energy requirement of a rural village as the basis of a system sizing and measured data from six village hydro schemes to determine the generation capacity. Through the field measurements carried out, availability of excess energy in orthodox village hydro system has been determined. A new rural energy solution based on improved energy utilization factor is proposed for both existing and new village hydro schemes. In the case of existing village hydro schemes, the recovered energy can be used to extend the energy services to several more rural households and in the case of new schemes, the solution can be used to bring down the cost of project by substantially reducing the power generation component sizes including auxiliary civil structures.
item: Conference-Abstract
Identification of influence of vehicle age and accumulated mileage on tailpipe emission–a review
(Transportation Engineering Group, Department of Civil Engineering, University of Moratuwa, 2023-12-08) Nimali, MSD; Sugathapala, T; Ranaweera, M; Jayantha, WRAN
Concerns regarding the sustainability of the environment and the quality of air are becoming more prevalent as a result of the heavy reliance on fossil fuels to meet the ever-rising global energy demand. The transport sector contributes significantly to this demand growth and to the consequential global emission inventories with the rapid acceleration of global urbanization and corresponding growth in vehicle population. Pollutants produced by vehicle exhaust cause numerous environmental and health issues. Vehicle parameters, fuel parameters, vehicle operating conditions, and environmental factors are known to influence vehicle emission levels. It is expected that the engine gradually wears out and emits higher emissions as the vehicle ages and its mileage grows. In addition, due to the degradation of the engine controls, the catalyst, and possibly the particle filter, vehicle exhaust emissions tend to rise with vehicle age. The technology change also significantly affects the exhaust emission level because modern engines are different from those made in the past and must adhere to stricter emission regulations. Despite this complex influence that vehicle age and millage have on emissions, only very little research has been done to investigate the matter. The aim of this review is to identify the state-of-the-art of research studies conducted to investigate the influence of vehicle age and accumulated mileage on tailpipe emissions of different vehicle categories. Therefore, this paper presents a critical review and a synthesis of empirical studies from both developed and developing countries such as Oregon, Switzerland, Indonesia, India and China, investigating the impact of vehicle age and accumulated mileage on exhaust emissions across different vehicle categories and research purposes. Most of the studies use inspection and maintenance data for their regions for this analysis. While some studies have directly assessed the impact of these two parameters on tailpipe emissions, others have examined the relationship between them to develop vehicle failure probability models, considering emission violations. Additionally, certain studies have aimed to develop emission factors. The results of the studies commonly show a direct influence of vehicle age and accumulated mileage on tailpipe emission constituents, mainly CO, HC, and NOx for all the selected vehicle categories. These emissions tend to increase as both vehicle age and accumulated mileage increase, however, following different trends. Some studies have observed linear relationships of change in emission constituents with these parameters, while others demonstrate logarithmic or polynomial regression trends. Similar patterns have been observed in the studies for both CO and HC emission changes with vehicle age and accumulated mileage. However, one study, which evaluated the test results for bus accumulated mileage only for a 2-year span, doesn’t show any clear upward or downward trend of emissions change with vehicle mileage, but only a decrease in fuel economy. Additionally, another study reveals higher emissions during idle test conditions compared to fast idle, following similar trend lines for both CO and HC change with respect to both vehicle age and accumulated mileage of different models of petrol Maruti passenger cars. In addition, one of the studies highlights that vehicles having engine sizes smaller than 2000 cc, older than ten years and odometer reading over 100,000 miles would significantly increase the 15 probability of identifying high polluting vehicles. Further, it shows that the increase in exhaust emissions is greater in non-passenger vehicles than in passenger cars. Compared to technological changes in vehicles, one study shows that Euro 2, 3, and 4 vehicles demonstrate emission improvements and show a linear increase in emissions with vehicle age. Nevertheless, Euro 1 vehicles still show the lowest level of stable emissions with respect to the vehicle age. In contrast, another study reveals emission improvements in Euro 1, 2, 3, and 4 vehicles in sequence, following linear emissions change with respect to the vehicle age. These findings demonstrate how newer vehicle technology has improved emissions compared to older ones. In conclusion, this review confirms that vehicle age and accumulated mileage have a direct influence on exhaust emissions, and the emissions increase as both vehicle age and accumulated mileage grow. However, due to the variation in factors such as vehicle category, emission test data, tested region, and conditions across different studies, it will not be possible to establish a common trend for emission changes or directly apply the findings to make required policy decisions to control emissions for other regions. Nevertheless, these results encourage us to carry out high-quality research in these domains to gain a better understanding of the local priorities and, consequently, design the necessary emission reduction strategies appropriate for the country. Thus, these factors must be considered for future studies.
item: Article-Full-text
Should We Care about how Birds Fly?
(2023-08) De Silva, L; Samaraweera, N; Jayaweera, N; Sugathapala, T
Bird flight has intrigued human minds ever since the Stone Age. Paintings in Lascaux cave in France are considered the oldest representation of birds in flight made by early ancestors of humans. The ability to fly has been interpreted as a divine power by some cultures which proceeded to include wings in drawings and sculptures of their deities. In the Renaissance period, Polymaths like Leonardo Da Vinci studied birds and their motion in detail. His codex of birds mentions the objective of this study as to develop a human-powered flying machine. Even, the Wright brothers used warping wings in their flight tests mimicking the flight patterns of birds. The wing and fuselage design of fixed-wing aircraft from the earliest versions to modern jet-powered airliners is directly inspired by the bio-mechanics of large birds. However, with the success of fixed-wing aircraft, the flapping wing concepts saw declining interest as a viable design option for air vehicles. During this time, the aerodynamics of bird wings was only studied in fundamental science to answer the questions on their aerodynamic performance. However, the popularization of Unmanned Arial Vehicles (UAVs) renewed the interest in bird-inspired air vehicles with flapping wings as a possible design.
item: Conference-Full-text
Study of the impact of electric vehicles on fuel consumption and carbon dioxide emission scenarios in Sri Lanka
(IEEE, 2020-07) Gajanayake, S; Thilakshan, T; Sugathapala, T; Bandara, S; Weeraddana, C; Edussooriya, CUS; Abeysooriya, RP
On par with the rapid motorization, fuel consumption and emission of greenhouse gases (GHGs) have become major challenges in the contemporary automotive industry. With a registered vehicle fleet of around 7.7 million road-vehicles and with an average survival rate of approximately 70%, Sri Lanka claims to an active vehicle fleet of around five million as of 2017. It can conspicuously be cited that 92% of the entire active fleet consists of Light Duty Vehicles which can be defined as the road-vehicles with a Gross Vehicle Weight Rating less than 3.5 tons. United Nations’ (UN) Sustainable Development Goals (SDGs) state ‘Affordable and clean energy as its 7th goal under which the target 7.3 is ‘doubling the improvement in energy efficiency’ directly aligns with the aim of the research study. Out of several approaches to mitigate the impacts of fuel consumption and emissions, electrification of the existing fleet and opting for electric vehicles as a new potential vehicle can be opted. The study analyses on the impact of electric two-wheelers, three-wheelers and cars on the fuel consumption and emission of GHGs in the national context forecasting on the future trends with increase in electric dominance to the traditional internal combustion engine vehicle.