Jazair Yahya Wira

Friction Characteristics of RBD Palm Olein Using Four-Ball Tribotester

In this study, the effect of load on the tribological performance of RBD palm olein is investigated using a four-ball wear tester according to the standard test of ASTM D4172. Tests were conducted with 40, 60, 80, 100 and 120 kg normal loads. The experimental temperature and rotational speed were held constant at 75 °C and 1200 rpm, respectively. The test duration was 60 minutes in all cases. For each load, the tribological properties of RBD palm olein were compared with the properties of additive-free paraffinic mineral oil. The results focused on the frictional torque, wear scar diameter, friction coefficient and the flash temperature. Following the completion of the wear test experiments, the ball wear condition and lubricant properties were observed. These results show that RBD palm olein has a lower coefficient of friction than paraffinic mineral oil; however showed a high oxidation effect under high temperature work conditions.

Effect of emulsion fuel on engine emissions-A review

Abstract Emulsion fuel is an unconventional fuel for diesel engines, which can be used without modifications in the engine. The benefits of an emulsion fuel include lowering the emissions of nitrogen oxides (NOx) and particulate matter (PM) which are harmful to health and cause diesel engines to suffer. This paper explains in detail the effect of water in the emulsion fuel on the emissions of NOx, PM, carbon monoxide (CO), hydrocarbon (HC), smoke and exhaust temperature. Experimental results from various researchers show a decrease in the NOx and PM emissions simultaneously. However, the results with the increasing water percentage in emulsion fuel are not consistent for HC and CO emissions. The water content in emulsion fuel affects the combustion and reduces the peak temperature in the combustion chamber. On the other hand, microexplosion phenomenon occurs and causes an increase in the volatility of diesel fuel which improves the combustion efficiency.

Stability Studies of Water-in-Diesel Emulsion

In general, water-in-diesel (W/D) emulsion reduces both particulate matter and nitrogen oxides gas emissions level in diesel engine application as compared of using conventional diesel fuel. W/D emulsion was usually produced by addition of water into the diesel fuel with a slight quantity of surfactant at high speed of propeller mixing. The studies examine the result of several aspects on emulsion stability. Investigated variables are type of surfactant, mixing speed and mixing time. Surfactant used are span 80 and many type of glycerines which have been derived from a corn oil, palm oil, soy oil, rice bran oil and sunflower oil. The results show that the type of surfactant gives a big impact on the stability period of the emulsion fuel. The higher mixing speed and less water percentage increase the stability period of W/D emulsion fuel. Optimum mixing time is 5 minutes for W/D emulsion fuel which using Span 80 as surfactant with mixing speed of 2500 rpm.

Utilization of Waste Hydraulic Oil as Fuel in Diesel Engine

Production of alternative diesel fuel has been increasing drastically in many Asian countries. Since the reduction of petroleum production by Organization of Petroleum Exporting Countries (OPEC), the research on alternative fuel for diesel engine has gain interest. The target of this project is to substitute some percentage usage of conventional diesel fuel with waste substance without compromising on engine performance and exhaust emissions. This study has produced two type of alternative fuels. A test fuel consisting 30% of water into diesel fuel with the existence of additive or emulsifier (span 80) is called as DW Emul. Another test fuel which is named as DHW Emul produced by blending 30% of water into a mixture consisting of 20% of waste hydraulic oil and 80% of diesel fuel with the existence of span 80. The engine performance and exhaust emissions of DW Emul and DHW Emul are measured and has been compared with the conventional diesel fuel. A 600cc single cylinder direct injection diesel engine was used. The experiment was conducted at 1500 rpm with variable engine loads. Results show that DHW Emul and DW Emul has higher brake specific fuel consumption (BSFC). However, by considering the total use of diesel fuel contained in DW Emul, the quantity was lower at all loads. The same goes for DHW Emul at low load but deteriorate at high load which show slightly higher compared with of using 100% conventional diesel fuel. DHW Emul has suppressed CO emission that is usually high of using emulsion fuel to the level similar to conventional diesel fuel. NOx and Smoke emissions for DHW Emul are lower than conventional diesel. The use of DHW Emul can give significant reduction of NOx and Smoke emissions without deterioration of CO emission.

Palm Fatty Acid Distillate as an Alternative Source for Hydraulic Oil

This study investigates the physical properties of pure palm fatty acid distillate (PFAD) as a new, clean and renewable source of lubricant and hydraulic oil. This study is done using a four-ball tribotester. The experiments are conducted at five different temperatures of 55, 75, 95, 105 and 125 °C. The rotational speed was fixed at 1200 rpm, normal load was 40 kg and duration was 1 hour. For evaluating the results, all experiments again were conducted using commercial engine mineral and hydraulic mineral oil and at the end all results were compared together. The results show that PFAD has higher anti friction and anti-wear ability.

The Effect of Sliding Speed on Friction and Wear of RBD Palm Olein

In this paper, the effect of sliding speed on the anti-friction of RBD palm olein was investigated using four-ball tribotester. The speeds were varied from 800 to 1400 rpm. The normal load was set to 40 kg and the test oil was heated up to 75 °C before the experiments. The result showed that palm olein has low friction coefficient compared to additive-free paraffinic mineral oil.

Experimental Study on the Effect of Different Speeds Applied with Palm Olein Using Pin-on-Disk Tester

The wide use of conventional lubricants causes pollution to the environment and the rising awareness on green house effect has triggered the use of environmental friendly and biodegradable lubricants in the industries. Palm olein was selected to be a candidate due to its superior tribological properties and large production in country. In the research, the behavior of palm olein characteristic was investigated by using pin-on-disk experiment in which the pin was loaded against the rotating grooved disk. The experiments by sliding were performed via pin on disk tester using stainless steel as the material for both flat ended pin and grooved disk. The test were carried out by dropping 5 ml of palm olein as lubricant on the sliding surface at two different speeds which were 0.25 and 1 m/s. In this study, the wear rate of the pin and friction coefficient was investigated. The weight loss and surface roughness before and after experiment were analyzed. All the results obtained were compared to hydraulic oil and paraffinic mineral oil. From the analysis, friction coefficient acquired with lubrication of palm olein was the lowest for both conditions, while the wear rate obtained also showed a similar trend. The pin lubricated with palm show the lowest result of wear rate and weight loss.

A new method to maintain lubricant layer in extrusion process

The present research concerns on the study of the effects of micro-pits arrays formed on the taper die surface. The micro-pits are diamond in shape. The evaluation of micro-pits was carried out by cold forward plane strain extrusion experiments. The experimental results were compared with the results obtained from the plane strain extrusion experimental works with taper die without micro-pits. The lubricant used in this experimental works is additive free paraffinic mineral oil. The experimental results are focusing on the extrusion load, billet surface roughness and grid pattern observation. From the result, the existence of the micro-pits influenced the extrusion load. At the same time, the micro-pits array affected the work piece surface roughness after the extrusion process. The lubricant viscosity also manipulates the quality of work piece after the experiments. From this works, we could conclude that the micro-pits formed on the taper die would create different frictional constraint compared to those without the micro-pits.

Wear characteristic of RBD palm olein using four-ball tribotester

Palm oil shows a great potential to be used as a lubricant. It is a vegetable oil which is environmentally friendly and has a high biodegradability in comparison to mineral oil. However, the research of the properties of palm oil based lubricant from the industrial point of view has never been widely conducted. In this research, the tribological properties of RBD palm olein; which is one of the palm oil refine product, was tested with four-ball tribotester to investigate its wear resistance. The testing method followed the ASTM D4172. The investigation was continued with 40kg, 80kg and 120 kg normal loads. For comparison, similar experimental and analytical works were done with additive-free paraffinic mineral oil and their results were compared with RBD palm olein. The analysis focused on the temperature properties, friction coefficient and wear observation. Results show that RBD palm olein has a good wear resistance performance in high and low temperature compared to additive free paraffinic mineral oil, especially at high normal load.

Study on noise generation in a high speed centrifugal fan

This study presents the investigation of aerodynamics and aeroacoustics of centrifugal fan using commercial computational fluid dynamics (CFD) code. The unsteady turbulent flow of the fan is simulated with Detached Eddy Simulation (DES) and the acoustics sources are computed based on the pressure fluctuations. The Ffowcs Williams and Hawking model is used to predict the tonal noises in aeroacoustics simulation.