Ridwan Saputra Nursal

Experimental studies have been carried out to investigate the effects of biodiesel fuels on the performance of a 4-stroke direct injected (DI) marine auxiliary diesel engine, brake specific fuel consumption (BSFC), carbon monoxide (CO), carbon dioxide (CO2), oxides of nitrogen (NOx) and hydrocarbon (HC) emissions, exhaust gas temperature (EGT), and cylinder pressure. Biodiesel fuels were prepared from Jatropha curcas oil and blended with petroleum diesel to specific designated concentration. All the measured parameters for biodiesel fuels are compared with the base diesel, i.e. petroleum diesel for different engine speeds. The biodiesel resulted in a slightly increased of brake power (BP), brake mean effective pressure (BMEP) and exhaust gas temperature (EGT) proportional to the engine speed under all rated loads while slightly reduced the brake thermal efficiency (BTE) throughout engine speeds as load was exerted to the engine. In the other hand, there is no significant change of BSFC by biodiesel fuels as well as diesel corresponding to the range of engine speed and loads. The present work contributes in using biodiesel fuels as alternative fuel for diesel engines without major changes for engines parts. For comparison between biodiesel and diesel fuels, the viscosity is not the main parameter affecting on engine performance and emissions.

This paper measure the carbon emission from small scale fishing boats. Carbon emissions were measured from two types Class A Malaysian fishing boats marine engines covering various size of inboard engines and outboard engines. The gas emission analyser MSA Altair 5x used is portable and easy to handle. Selected fishing boats were sampled from a total of 664 fishing boats operates in Manjung, Perak. The results of carbon emission measurement were presented in parts per million (ppm). The outboard powered fishing boats recorded the highest carbon value in ppm about 2000 ppm meanwhile inboard powered fishing boats constitutes slightly less carbon emission with 379 ppm. The results signify that outboard engine fueled by petrol producing more carbon value if compared with inboard diesel engine. These results can be an initial data for carbon emission inventory for local fishing boats.

Numbers of studies has been executed globally in order to seek the alternative way to replace the current fossil-fuel with regards to the rising of fuel-energy demand, running-out of petroleum reserves and to attain the cleaner atmosphere. For that reason, the exploration and studies on Biodiesel Fuel (BDF) has been one of the potential alternative. Thus, a research has been carried out to investigate the effects on performance and exhaust gas emissions of a single cylinder, 4-stroke marine diesel engine with capacity of 638cc using biodiesel blends derived from Crude Palm Oil (CPO) along with neat diesel (DSL) that driven as standard reference. The CPO fuel was blended with DSL in various concentration to produce blended fuels that comprise CPO5, CPO10, CPO15 and CPO20. The CPO biodiesel was chosen in the study due to the availability and readiness of its feedstock sources in Malaysia all over the year. Moreover this research was focusing on marine engine compared to the most today’s research which commonly engaged with automotive engines. The outcomes of this research found that the used of CPO blends fuels promotes to some extent of better performance of marine diesel engine and comparable exhaust gas emissions. The finding from this research also verified that the different levels of blending concentration have its pros and cons on the effects of engine performance and gas emissions. The used of crude palm biodiesel fuels however do good to the marine diesel engines which it can be ran without adjustments in equatorial regions.

Operating a ship is very critical especially when the bad weather conditions. Therefore, a good and durable engine is especially important when the weather is bad. It is important to make periodic care or maintenance based condition of the engine to ensure that engine capabilities can help facilitate the operation of the vessel. This paper presents study of 2-stroke main propulsion marine diesel engine characteristic using ultrasound signal monitoring condition based maintenance (CBM). The increment of operation and maintenance cost was significantly increase the life cycle cost and it might interrupt the efficiently and return of investment in any particular asset, as in this project is the main propulsion 2-stroke marine diesel engine. The condition based maintenance (CBM) could be one of the option to reduce the maintenance cost and increase the efficiently of the main propulsion engine. The condition based maintenance (CBM) is the option for ship’s owner to gain the profit margin with shrinking the performance of the engine. CBM is the proposed method for performing operation or maintenance and it was applied in various industries such as aviation industries, marine industries and power plant sector. Wave spectrum analysis using ultrasonic signal and wave sensor is one of the CBM method that can be applied for early identifying the excessive friction. In this study, both method condition based maintenance and wave spectrum analysis be utilized together for identifying the main engine performance without involving major and complex procedure. Most important of criterion for boost the profit margin are the reliability, availability, repairing, installation costs, operating costs, flexibility and engine size. Failure to optimize the performance of the main engine will tremendously reduce the company profit margin. This study suggested that once the engine is operating within the operating limit and that wave spectrum and signal show the decrement of wave amplitude, the engine is in good condition and no major maintenance required. If the working parameter is out of the range, and significant friction detected using wave spectrum analysis, then the maintenance is required. Therefore, both condition based maintenance and wave spectrum analysis or signal monitoring is a good combined method to identify the engine performance and able to reduce the maintenance cost that using the conventional maintenance schedule.

Blended fuels have great potential for substitution with petroleum fuel for the purpose of emission control and fuel efficiency improvement. This research is to investigate the effect of high injection pressure and high ambient condition of biodiesel blends on spray characteristics using Computational Fluid Dynamics (CFD). The variables in this study are the various injection pressure (220, 250 and 280 MPa) and ambient temperatures (850, 950, and 1050 K), while the ambient pressure is kept constant at 8 MPa. The simulation in ANSYS FLUENT was used to observe the spray characteristics of biodiesel blends at various conditions. Simulation results show that longer spray penetration length with smaller spray significantly affects the mixture formation biodiesel blends compared to pure diesel at high injection pressure and ambient temperature.

Global warming and energy crises have increased the awareness about eco-friendly fuels and also accelerated the search of alternative fuels. Biodiesel is defined as methyl esters of long chain fatty acids derived from vegetable oils or animal fats or similar which conform to ASTM D6751 specifications for use in diesel engines. However, low temperature combustion mode has attracted widespread attention in particulate matter and NOx emissions reduction simultaneously. Thus, this paper focuses on experimental investigation for the influence of ambient temperature on ignition delay and emission with different types of biodiesel. A Rapid Compression Machine (RCM) is used for simulated the diesel combustion as similar in the real diesel engine. Besides, two types of biodiesel blends, B2 (2 vol%) such as Algae and Jatropha biodiesel were tested on RCM at injection pressure of 130 MPa under different ambient temperatures from 750K to 1100K. The experimental results were compared with Palm-Oil biodiesel with blending ratio of 5%, 10% and 15%. Nevertheless, the result indicated that the ignition delay is slowed when ambient temperature is increased. These phenomena can be explained by the thermal properties of fuels. Ignition delay is found to be slower if premixed combustion process is reduced and also higher ambient temperature due to the increased in fuel ignitibility. The emission of NOx increased as the ambient temperature increased to cause highly combustion temperature.

Biodiesel is typically made by chemically reacting lipids of palm, vegetable, and waste cooking oils and animal fat with an alcohol producing fatty acid esters. Biodiesel is not efficient in cold weather and this is biodiesel's major problem. Viscosity has influences on the fuel flow rate and leads to poor fuel atomisation during the combustion process. The aim of this study is to determine the effects of biodiesel temperature in the range fom 40°C and 60°C on engine performance such as torque, brake power, brake mean effective pressure, and fuel consumption. Three types of biodiesel oil were used (crude palm oil (CPO), waste cooking oil (WCO), and jatropha oil) under biodiesel blending ratio of 5vol%. A single cylinder four-stroke engine was used and operated under different load conditions of 0% and 50% and observed emission of CO, CO2 , NOx, and HC. The engine operated at 0% and 50% dynamometer load conditions and running speeds of the engine of 800 rpm, 1200 rpm, 1600 rpm, and 2000 rpm. The results of this study showed that the heating temperatures in the range from 40°C and 60°C in CPO10 produced the highest brake power as well as torque and BMEP. For the experimental results of exhaust emission, the preheated temperature affected the degradation of the exhaust emission. In addition, preheated biodiesel increased the pressure on the cylinder combustion chamber. It can be concluded that the biodiesel preheated blend influences the performance and emission. For CPO biodiesel, the preheated biodiesel decreased CO and NOx while the standard diesel produced the lower emission of CO2 and HC. WCO biodiesel blend produced a lower emission with increasing fuel temperature.

In recent years, high speed vessel received additional attention and being developed intentionally for catamaran boat race, passenger vessel, military vessel and recreational purposes. Most of hull forms used in these high speed boat types is multi-hull. Whilst the twin hull type vessel is the most popular among the multi-hulls because of their inherent features such as large deck area, better stability, lower wave-making resistance at high speeds and better safety. Since the propulsive power of any marine vehicle depends mainly on its resistance characteristics, it is required to predict the resistance of the vessel either in theoretically, experimentally and numerical study. In the present study, an attempt has been made to carry out both experimental and numerical investigations on the resistance characteristics as well as the comparison of an existing twin hull without tunnel used in developed of human powered hydrofoil. This study is expected to minimise the variation of resistance in range of 10% or less between both methods.

Biodiesel is one the most popular bio-derived fuel among the alternative fuels. The biodegradable, environmental friendly and easy resources are causing biodiesel received extra attentions by industries and researchers in addition to solve the future energy crises. Despite years of improvement, the crucial issue in using bio-derived fuels is the oxidation stability, stoichiometric, chemical composition, antioxidants on the degradation and much oxygen compared to diesel. Thus, the improvement of emissions quality from engines fuelled by biodiesel is immediately required to meet the future stringent emission regulations. Instead of using biodiesel itself, the used of biodiesel blended with additive has been experimented extensively aiming the emissions reductions and improving the engine performance. Therefore, this study was executed to analyze the effects of biodiesel mixed with bio-additives on performance, emissions and combustions characteristics of diesel engine. The division of experimental investigation comprises of 1) performance of diesel engine specifically on brake power, brake mean effective pressure and fuel consumption; 2) exhaust gas emissions focusing on CO 2 , NOx, HC and CO formations; and 3) combustion characteristics of fuel inside the combustion chamber. Biofuels tested in the study was derived from three different feedstock's i.e. crude palm oil (CPO), jatropha curcas oil (JCO) and waste cooking oil (WCO) at 5, 10, 15 and 20% concentration were blended with selected bio-additive namely Di Methyl Poly Siloxane (DMPS) and D20 palm oil methyl bio-additive formula. Additionally, petroleum diesel namely standard diesel (STD) was examined as well for comparison purpose. A 4-cycle YANMAR TF120ML diesel engine integrated with a 20 HP Eddy-Current dynamometer and mounted with Airrex HG-540 gas analyzers are used. Outcomes of the study implied that blended fuels particularly C10+DMPS and J15+DMPS promotes the optimum performance associated with reduction of exhaust emission specially CO gas. Yet, the best alternative fuels were recommended.

In order to reduce the global environmental impact from internal combustion engines in terms of emissions particularly in the production of greenhouse gases (GHG), one of the most promising ways is the use of bio-derived fuels. To this purpose, the utilization of biodiesel (pure or in blends) in diesel engines is already quite common in some countries due to its properties comprehensively similar to petro-diesel. The major positive effect not only intrinsic to the significant reduction in CO 2 emission but reducing CO, HC and smoke emissions, even though it typically causes an appreciable increase in NOx emissions. However, the use of the biodiesel has some limitation due to efficiency drops and long term complications to the engine. Therefore, this study aims on examine the effects of different biodiesel blends on engine performance and exhaust gas emissions of marine auxiliary diesel engine and recommends bio-fuel that optimizing the engine performance and lower emissions. This study found there has been an increment in engine performance specifically on torque, brake power, brake thermal efficiency (BTE) and brake mean effective pressure (BMEP) along with lower and better in brake specific fuel consumption (BSFC) crude palm biodiesel oil (CPO) and jatropha cursas biodiesel oil (JCO) blended fuels, while decreased in engine performance associated with higher BSFC by waste cooking biodiesel oil (WCO) blends compared to neat petroleum diesel. Aside, the reductions of CO, CO 2 and HC by CPO; slightly increment in CO 2 , NOx and HC by JCO and acceptable CO 2 , CO and NOx gas productions by WCO has been discovered. Conclusion can be made is biodiesel blend fuels is operable in diesel engines without engine alterations as well as advantageous for exhaust emission reductions yet beneficial to the environmental sustainability.

This study is to analyse the exhaust backpressure of older and new exhaust piping design and silencer or muffler position after modification of the exhaust system of a 4-stroke marine diesel generator which operates at Marine Generator Workshop, Ungku Omar Polytechnic, Malaysia. The purpose of the exhaust system modification is to collect the exhaust gases produced inside combustion chamber of the engine cylinders and discharge them as quickly and silently as possible to atmosphere. Generally the better a silencer or muffler is at attenuating sound the more backpressure is generated. In a reactive silencer where good attenuation is achieved, the exhaust gases are forced to pass through numerous geometry changes of exhaust system and a fair amount of backpressure may be generated, which reduces the power output of the engine slightly. However, too much backpressure generated may led the power losses, weakening the engine performance and increased the fuel consumption. Henceforth, the study is aims to find the relationship between the exhaust backpressure levels occurred in exhaust flow design as well as silencer position and yet propose the best design to ensure the optimisation of engine performance. The actual dimensions of the exhaust system is used to perform the computational fluid dynamic (CFD) simulation and analysis. The performance of an exhaust system is based on velocity and exhaust backpressure. Investigation in CFD was performed on four parameters comprises manifold temperature, manifold pressure, exhaust piping system temperature and atmosphere pressure. Results of CFD simulation was showed in the form of pressure and velocity contours and streamline. This study found the modification of exhaust piping design of the 4-stroke marine diesel generator increased the backpressure up to 94.7%.

Alternative fuels for diesel engines have become increasingly important due to several socioeconomic aspects and increased environmental concerns. Global warming concerns due to the production of greenhouse gases (GHGs) have seen as one of major factor the promotion of the use of biofuels. Carbon dioxide (CO2) from fuel combustion is a major contributor to GHGs and caused a shift in the climate system. Yet the use of biodiesel as an alternative fuel for petroleumdiesel fuel operates in compression ignition (CI) diesel engines is very effective for the reduction of CO2 emission since it is classified as green and renewable energy. It is now acknowledged that the use of the biodiesel blends fuel is restricted due to loss of efficiency and long term problems in the engine associated with worsen the atmosphere pollution. Hence, this study targets on investigating the effects of various biodiesel and fossil diesel blends fuel on engine performance and exhaust gas emissions of small diesel engine and yet recommends bio-fuel that optimise the engine performance and lower exhaust emissions. As results of experimental investigations, there has been a decrease in performance of torque, brake power, brake thermal efficiency (BTE) and brake mean effective pressure (BMEP) while increase in brake specific fuel consumption (BSFC) has been observed for all biodiesel blend fuels over the entire speed range and load test compared to diesel fuel (DSL). In conjunction, exhaust gas emissions, signified the higher formations of NOx emissions while reductions of CO, CO2 and HC gases corresponding to the increasing of biodiesel blending ratio. Increased blends of biodiesel ratio are found to enhance the combustion process consequently decreased the emission elements. It can be concluded that biodiesel blend fuels can be used in diesel engines without any engine modifications and have beneficial effects both in terms of emission reductions and alternative petroleum diesel fuel.