The effect of fluidity of palm kernel oil with pour point depressant on coefficient of friction using fourball tribotester

The growing awareness worldwide of the need to promote the use of renewable materials such as vegetable oils is due to increasing concerns about the damage to the environment that is being caused by the use of non-biodegradable mineral oils. Vegetable oils have the potential to replace mineral oils as a lubricant because of their specific properties, namely that they are non-toxic and biodegradable. The main problem with the use of vegetable oils is that they perform poorly at low temperatures. In this research, palm kernel oil (PKO), which behaves as a semi-solid, was used as a bio-lubricant by mixing it with different weight percentages of a pour point depressant (PPD) to investigate the performance of the pour point depressant and also to determine the effect on the lubricity of the bio-lubricant when it is blended with different percentages of PPD (5 wt.%, 10 wt.%, 20 wt.% and 30 wt.%). The experiment was conducted according to ASTM D4172 and ASTM D2783. The results of the experiment showed that at low temperatures the PKO samples with 20 wt.% PPD and 30 wt.% PPD performed well, where they were able to remain in a liquid form at a temperature of 15°C. From all antiwear test result, the coefficient of friction for the PPD sample shows poor tribological performance when adding PPD into the palm kernel oil

The tribological performance of modified RBD palm kernel oil under extreme pressure load test

Lubrication is one of the most used components globally in various types of applications. The hiking in demand of lubrication oil annually rise several issues such as environmental wastage and oil supply. This paper discussed the alternate option of lubricant oil performance from renewable resources that helps to preserve the environment and support the current mineral oil supply. Refined Bleach and Deodorised Palm Kernel Oil was used in this research as tested lubricant undergone normal load test (ASTM D4712) and extreme pressure (ASTM D2783) according to the ASTM test standards. The Refined Bleach and Deodorised Palm Kernel Oil was tested at two conditions of semi-solid form and liquid form. A liquid form of Refined Bleach and Deodorised Palm Kernel Oil was synthesized with transesterification process to convert the semi-solid form into liquid at room temperature. Results shows that Refined Bleach and Deodorised Palm Kernel Oil performance was comparable to the fully synthetic oil in terms of COF, WSD, and surface roughness while in the extreme pressure test shows that ISL of palm-based oil are slightly lower than fully synthetic oil by 127N

The evaluation of drag and lift force of groove cylinder in wind tunnel

Cylindrical structures subjected to flow are widely used in marine and offshore engineering and in structural applications. It has been shown that circular cylinder surface modifications can affect the separation point to move backward on the cylinder surface. Thus, reducing the drag coefficient. Flow past a circular cylinder with smooth, half and full rectangular, grooved surfaces (roughness coefficient k/D=0.04) were investigated in a low-speed open ended wind tunnel. The outer diameters (D) of the cylinders were 50mm and the depths (k) of the grooves were 2mm. The Reynold's number ranged from 1.65x104 to 1.13x105. The drag and lift coefficients of the cylinders were measured using a three-component balance. The wake flow patterns of the cylinders were observed using a smoke visualization technique. The results show that the full grooves and half grooves facing the flow produced a lower drag than a smooth cylinder with a half groove located at the leeside of the flow. The full grooved cylinder showed a drag reduction of 55% at Re=1x105. The presence of the groove on the cylinder's surface tripped the boundary layer and showed a smaller and narrower wake than a smooth cylinder