Firmansyah Firmansyah

• PhD
• PETRONAS

Fulfilling electricity demand in a remote platform has been a great challenge for oil and gas industry. With only pressurized gas line available, the choice of technology that can be implemented is limited; one of it is impulse gas turbine. At the moment, no studies investigating the performance of a compact impulse gas turbine which utilizes press...

The thermal efficiency (40-50 %) of free-piston linear generator (FPLG) engines is widely known to be higher than the conventional reciprocating engine (CRE) (30–40 %). Future technology to optimise FPLG engine combustion necessitates the identification of a stroke to bore ratio (Aspect Ratio, AR). This paper presents a report on the effects of dif...

Free-piston linear generator (FPLG) engines currently gained great attention due to their capability to operate with variable fuel and compression ratio. This paper presents an experimental study on the effect of aspect ratio on the performance characteristics of the FPLG engine fueled by hydrogen. Three aspect ratios (i.e. 1.0, 1.5, and 2.0) are u...

This chapter introduces the working principle, potential applications and current developments of free-piston engines (FPE) used for electricity generation. FPE is essentially a type of internal combustion engine (ICE) with its crankshaft mechanism removed to reduce total weightage and friction loses. However, since engine control conventionally re...

This chapter reviews reactivity controlled compression ignition (RCCI), which is an advanced combustion mode. RCCI is capable of improving thermal efficiency and reducing nitrogen oxides (NOx) and soot emission. However, it has high specific fuel consumption, unburned hydrocarbon (UHC) and carbon monoxide (CO) emissions, and thus requiring appropri...

This chapter describes the approaches used in micro-explosion studies, fundamentals of the micro-explosion processes, and the main factors influencing the micro-explosion behavior. Moreover, this chapter briefly discussed the effect of injection equipment on the dispersed water droplets size and the results related to their micro-explosion behavior...

Hydrogen’s high flammability, low ignition energy, clean burning, and high flame speed are attractive advantages of using internal combustion engines to attain high performance and efficiency as well as achieving “real” clean emission with only water and carbon dioxide as exhaust. To overcome volumetric efficiency loss, high NOx emissions and abnor...

The study of flame commencement and growth in SI engine has attracted the attention of many researchers due to its strong dependence to the in-cylinder flow and its capability to influence flame propagation characteristics in SI engines. Optical visualisation has been one of the prominent techniques utilized in this study of the early flame propert...

This paper studies the effect of intake manifold in order to obtain minimum turbulence and lower pressure drop. The pressure input was 1.2 bar where the effect is equal to turbocharge concept in conventional engine due to the stroke length. The experiment has been conducted in order to validate the method of theory with experimental PIV and CFD sim...

The effect of late fuel injection positions on the combustion characteristic of a two-stroke free piston linear generator engine were conducted experimentally. Three fuel injection positions namely 39, 42 and 45 mm from the cylinder head were selected. The ignition position was set at 12 mm from the cylinder head, while the equivalence ratio was fi...

This paper presents the investigation on the effects of throttle position variations on the performance characteristics of a single-piston curved-cylinder four-stroke SI Crank-Rocker (CR) engine fitted with a conventional engine cylinder head. The CR engine is a new alternative IC engine for which the performance characteristics are still being inv...

Free piston engine generator (FPEG) in the engine system can be considered as a linear energy conversion system. Cascade control for the stability of piston operation level and PID controllers are proposed for both the outer and inner loop. The free movement of the piston in the cylinder an adjust the compression ratio and optimize the combustion p...

Free piston engine (FPE) is a promising alternative to conventional internal combustion engine (ICE) as it has the potential to operate with higher efficiency and produce lower emission. The absence of a crankshaft mechanism is what differs FPE from conventional ICE and provide advantages such as less friction losses and adjustable positions as wel...

The free piston linear generator (FPLG) is a kind of linear free-piston engine and has many advantages over the conventional internal combustion engine. In this study, a novel two-stroke free piston linear generator prototype equipped with a linear electric generator is presented to achieve efficient conversion of mechanical work to electricity dur...

In this paper, the bouncing phenomena of Free Piston Linear Generator (FPLG) and its influence on dynamic and combustion performance of FPLG during the starting process have been investigated. Using Simulink, FPLG was simulated by injecting compressed air at the combustion chamber and the piston was allowed to expand until bouncing phenomena occurr...

Increasing concern on the environment and energy security boosts the technological development of internal combustion engine with the main objectives are higher overall efficiencies and lower emissions. Split cycle engine is one of the unconventional solution for the current established engine technology. However, its high pressure ratio intake bet...

Water-in-diesel emulsions potentially favor the occurrence of micro-explosions when exposed to elevated temperatures, thereby improving the mixing of fuels with the ambient gas. The distributions and sizes of both spray and dispersed water droplets have a significant effect on puffing and micro-explosion behavior. Although the injection pressure is...

Proper orthogonal decomposition (POD) is a coherent structure identification technique based on either measured or computed data sets. Recently, POD has been adopted for the analysis of the in-cylinder flows inside internal combustion engines. In this study, stereoscopic particle image velocimetry (Stereo-PIV) measurements were carried out at the c...

Reactivity controlled compression ignition (RCCI) is found promising low temperature combustion mode that has recorded tremendous success towards improving thermal efficiency and reducing NOx and soot emissions to nearly zero but has high specific fuel consumption, unburned hydrocarbon (UHC) and carbon monoxides (CO) emissions. Besides, RCCI requir...

Study on the behavior of Free Piston Linear Generator (FPLG) motion using gas spring. The potential energy from the bouncing behavior can be used to control the compression pressure of FPLG as well as improve the combustion process

The effects of varying the ignition timing on the performance and emissions characteristics of a crank-rocker engine were experimentally investigated. Experiments were carried out at five different ignition timings of 6.5°, 8.5°, 10.5°, 12.5°and 14.5° CA BTDC at engine speed of 2000rpm and wide open throttle position. Performance data such as brake...

In consideration of its vast resources in Malaysia, the potential use of a nonedible biodiesel source from rubber seed oil (RSO) is explored. However, a mixture with a high saturation content feedstock is required to increase its oxidation stability, which is caused by its 78.93% unsaturation content. Two blends of 20% and 50% v/v rubber seed biodi...

The use of a clean fuel such as biodiesel has both environmental and economic advantages. The environmental advantage is reduced emissions, whereas the economic benefit stems from local availability of raw material and improved energy security. Currently most of biodiesel production comes from edible sources such as soybean, palm and sunflower oils...

Combustion phasing is the main obstacle to the development of controlled auto-ignition based (CAI) engines to achieve low emissions and low fuel consumption operation. Fuel combinations with substantial differences in reactivity, such as diesel/compressed natural gas (CNG), show desirable combustion outputs and demonstrate great possibility in cont...

Better performance and higher efficiency of the vehicles can be achieved by using free piston engine, in which the piston is connected directly to the linear generator and waiving of any mechanical means. The free piston engine has the ability to overcome or reduce many of the challenges, such as the carbon dioxide (CO2) emission and fossil fuel co...

Alternatives to hydraulic drives that used on vehicles are necessary in order to reduce the Carbon dioxide (CO2) emission and oil consumption. Hence better performance and efficiency of the vehicles can be achieved by using free piston engine, in which the piston reciprocate linearly with a permanent magnet linear generator (PMLG) without the need...

An experimental study was conducted to investigate the effect of the structure of the induction flow on the characteristics of early flames in a lean-stratified and lean-homogeneous charge combustion of compressed natural gas (CNG) fuel in a direct injection (DI) engine at different engine speeds. The engine speed was varied at 1500 rpm, 1800 rpm a...

Global energy consumption grows faster than world population. It is projected that the next growth will be driven by developing countries in Asia region. As energy consumption rises, the awareness of environmental issues related with fuel and energy consumption gradually grows. One solution for these issues is the use of renewable energy. However,...

The product of gasification of solid biomass, also called syngas is believed to be good fuel for internal combustion engines in the move from the carbon based fuel to zero emission fuels. The only problem is its lower calorific value which is placed at one third of that of compressed natural gas (CNG). There are latest efforts to enhance the hydrog...

Generating power is of great importance nowadays across the world. However, recently, the world became aware of the climatic changes due to the greenhouse effect caused by CO2 emissions and began seeking solutions to reduce the negative impact on the environment. Besides, the exhaustion of fossil fuels and their environmental impact, make it is cru...

The stringent emission regulations and the need to increase fuel efficiency makes controlled auto-ignition (CAI) based combustion an attractive alternative solution to these issues. However, the combustion control is the main obstacle to its development. Fuel combinations with substantial different in reactivity such as diesel/compressed natural ga...

This paper investigates the potential of utilizing the undeveloped natural gas fields in Malaysia with high carbon dioxide (CO2) content ranging from 28% to 87%. For this experiment, various CO2 proportions by volume were added to pure natural gas as a way of simulating raw natural gas compositions in these fields. The experimental tests were carri...

The stringent emissions and needs to increase fuel efficiency makes controlled auto-ignition (CAI) based combustion an attractive alternative for the new combustion system. However, the combustion control is the main obstacles in its development. Reactivity controlled compression ignition (RCCI) that employs two fuels with significantly different i...

One configuration of the hybrid electric vehicle (HEV) is the split-axle parallel hybrid, in which an internal combustion engine (ICE) and an electric motor provide propulsion power to different axles. A particular sub-type of the split-parallel hybrid does not have the electric motor installed on board the vehicle; instead, two electric motors are...

Homogeneous Charge Combustion Ignition (HCCI) operating principles have been widely investigated, yet the uncontrollable combustion of HCCI is the major obstacle in its development. The combustion characteristics of single fuels have been widely investigated as the fuel is the most influential factor that determines the HCCI combustion behavior. Ho...

Homogeneous Charge Compression Ignition (HCCl) engines have become potential power units to satisfy the stricter emission regulations and obtain higher thermal efficiency values. The HCCl operating principle has been widely investigated in order to improve the ability to control the HCCl combustion phasing. The zero dimensional model, Wiebe functio...

Cloud computing is an extension of Service Oriented Architecture (SOA). For cloud elastic nature, it will often need to dynamically reconfiguring and reorganising the services interaction as some unpredictable events, such as crashes or network problems, will typically cause service unavailability. The complexity and dynamism of current global netw...

The performance of two impellers (Rushton and Elephant ear) for waste cooking oil (WCO) transesterification were experimentally and numerically evaluated inside a unbaffled and baffled stirred tank reactor (STR). Three parameters (impeller bottom distance (C), speed, (N) and temperature) were investigated for fatty acid methyl esters (FAME) yield u...

The experiments to determine the effect of fuel-injection timings on engine characteristics and emissions of a DI engine fueled with NG-hydrogen blends (0%, 3%, 5% and 8%) at various engine speeds were conducted. Three injection timings namely 120°, 180° and 300° CA BTDC with a wide open throttle at relative air–fuel ratio, λ = 1.0 were selected. T...

Homogeneous Charge Compression Ignition (HCCI) engine has become a potential power unit to satisfy the stricter emission regulations and obtain higher thermal efficiency values. However, main issues are the uncontrollable combustion of HCCI, which is unfavorable for engine application. Dual fuel application in HCCI is applied to overcome the diffic...

Implementation of natural gas as the fuel of internal combustion engine is increasing in order to discover the environmental friendly technology. However, there is a drawback in implementing natural gas as fuel which is engine power output. To overcome this drawback, improving combustion process of natural gas by regulating spray parameter is a way...

An experimental study was carried out on a dedicated compressed natural gas direct injection (CNG-DI) engine with a compression ratio (CR) of 14 and a central injection system. Several injection timing parameters from early injection timing (300° BTDC) to partial direct injection (180° BTDC) to full direct injection (120° BTDC) were investigated. T...

The effects of fuel rail pressure variations on the performance of a compressed natural gas (CNG) direct injection (DI) engine is presented. In order to maximize the performance, the engine was designed with a compression ratio of 14 and equipped with central DI system. The results presented focused on the effect of lowering the injection pressure...