Synergistic Performance of Expanded Graphite – Mica amalgamation based Non-Asbestos Copper-Free Brake Friction Composites

Recent advancements in brake pad applications emphasise various friction compositions that exclude toxic components such as asbestos, copper etc., in order to provide superior performance without hurting the environment, human life and aquarium species. In this work, brake friction materials were fabricated by the conventional manufacturing process as standard brake pads using expanded graphite with the synergetic effect of thermal resistant material mica flakes. Six standard brake pads were produced based on varying the expanded graphite by 16, 14, 12, 8, 6 & 4 weight percentage, which is compensated using the Mica flakes by 4, 6, 8, 12, 14 & 16 weight percentage, fixing the composition of other ingredients and designated as BM01, BM02, BM03, BM04, BM05 and BM06. Physical, chemical and mechanical, characterisations of the formed friction materials were carried out in accordance with IS 2742 and ISO 6312. A full-scale inertia brake dynamometer was used to determine the fade, recovery characterisations with the pressure and speed sensitivity as of JASO-C-406. From the experimental observations, BM03 friction composites reveal excellent low fade and high recovery characteristics because of the integrated effect of expanded graphite (superior lubricity) & mica (good thermal stability). Worn surface analysis was studied with the help of a scanning electron microscope. The inclusion of expanded graphite-mica as a hybrid “lubricant-filler” combination in composite materials for friction braking application results in performance synergism.

THE EFFECT OF BRASS (Cu-Zn) CATALYTIC CONVERTER ENGINE PERFORMANCE

Installing a catalytic converter in the exhaust is a typical method of reducing engine exhaust emissions. Catalytic converters have been shown to lower exhaust pollutants while enhancing engine performance. The influence of the number of brass catalyst plates (Cu-Zn) on the Performance of the commercial Yamaha Jupiter MX motorcycle engine manufactured in 2007 was investigated in this study. The catalyst is installed in the motorbike exhaust, with the number of catalyst plates varying between 5 and 8, and a conventional uncatalyzed exhaust serving as a comparison. Torque, power, specific fuel consumption, and thermal efficiency are among the performance factors that will be considered. A prony brake dynamometer was used to conduct torque and power measurements. The results indicate that exhaust with eight catalyst plates can improve engine performance more than an exhaust with five catalyst plates. Furthermore, exhausts equipped with eight catalyst plates can boost engine efficiency by an average of 17.65%. Thus, increasing the number of catalyst brass plates improves the machine's efficiency.

Synergic effect of metallic fillers as heat dissipaters in the tribological performance of a nonasbestos disk brake pad

Brake friction linings are made of materials with a highly complex formulation that helps in improving the braking performance. The selection of friction materials with good physical, mechanical, and thermal properties is vital, which will decide the braking performance. Apart from giving good physio-mechanical properties, metallic fillers act as heat dissipaters. The objective of this work is to study the synergetic effect of prominent heat dissipaters, namely copper fibers, brass fibers, and zinc powders. Three simplified formulations were developed with 10, 14, and 18 wt.% of these heat dissipaters and named DB1, DB2, and DB3, respectively. It was observed that the addition of heat dissipaters increased the thermal properties. Tribological properties are tested based on SAE J661 standards. It was observed that DB2 had a consistent and higher coefficient of friction of 0.503 with a higher wear rate (7.6%) while DB3 had adequate μ and lower wear rate. The same batches of brake pads were tested in an inertia brake dynamometer following JASO C406 and a wear test was carried out. It was observed that % fade and % recovery were better for DB2 in both cycles. The wear rate in terms of thickness was lesser for DB2 followed by DB1 and DB3. The wear mechanism was analyzed using a scanning electron microscope. The preference selection index method of optimization was used to evaluate the overall performance parameters of the brake friction composites. Heat dissipaters with 14 wt.% have proved to be the better performers, followed by 10 and 18 wt.%.

Enclosure Design for Brake Wear Particle Measurement Using Computational Fluid Dynamics

The harmfulness of fine dust generated by automobile brakes to the environment has recently received attention. Therefore, we aimed to analyze and regulate the brake wear particles in dynamometers. To accurately measure the number of particles and particle mass, the sampling system used needs to minimize transportation losses and reduce the residence time in the brake enclosure system. The brake dust measurement system currently used can estimate the main transportation loss but cannot evaluate the complex flow field in the brake enclosure system under different design conditions. We used computational fluid dynamics (CFD) technology to predict the behavior of brake wear particles and analyze the static pressure characteristics, the uniformity of the system flow, and the residence time of the brake dust particles in the system. In addition, we compared the design of the basic structure of the brake enclosure system, combined with the four factors affecting the design of the brake dynamometer, with the enclosure system. As a result, we proposed that the design of the cross section of the brake dynamometer enclosure should be circular, the outlet angle of the enclosure should be 15°, the caliper should be fixed to 150°, and two sets of splitters should be added. This design improves pressure loss and reduces the residence time of brake dust particles in the brake enclosure system.

Studi eksperimen kinerja turbin vortex berbasis gravitasi dengan sudu backward dan forward

Nowadays, the use of hydro energy in Indonesia is still focused on large-scale hydropower development which has negative effects on the environment such as changes in the natural flow of rivers, disruption of the population of aquatic biota that live in these watersheds and has the risk of potential disasters if the dam fails. In fact, the energy potential from the mini-micro hydro source is 19,835 MW, but its utilization is still very low around 100 MW. Therefore, the extraction of water flow energy in the form of rivers and irrigation channels with very low head altitude differences is considered important and urgent so that a gravity vortex turbine-based mini / micro hydro research is proposed. Specifically, this study aims to analyze the performance of the vortex turbine with backward and forward blades in a conical basin through laboratory experimental devices. Experiments were carried out on a fluid flow rate of 120 liters per minute (lpm) and 100 lpm by loading using a prony brake dynamometer in order to obtain torque performance data on variations in turbine blade rotational speed. In this experiment, the results showed that the performance of the backward blade turbine was superior with its optimal efficiency reaching 36.7% at a discharge of 120 lpm and a rotating speed of 80 rpm than the forward blade which at a discharge of 120 lpm and a rotating speed of 80 rpm was only able to achieve its highest efficiency at 33.19%.

Particle Emissions and Disc Temperature Profiles from a Commercial Brake System Tested on a Dynamometer under Real-World Cycles

The particle emissions from a commercial brake system utilizing copper-free pads have been characterized on a brake dynamometer under two real-world driving cycles. These included a novel cycle developed from analysis of the database of the World Harmonized Test Procedure (WLTP-Brake) and a short version of the Los Angeles City Traffic cycle (3h-LACT) developed in the framework of the European LowBraSys project. Disc temperature measurements using an array of embedded thermocouples revealed a large temporal and spatial non-uniformity with the radial temperature distribution depending also on the test procedure. Averaging over the duration of the cycle, it effectively reduced the influence of thermocouple positioning, allowing for more reliable quantification of the effectiveness of convective cooling. Particulate Matter (PM) emissions were similar for both cycles with PM2.5 averaging at 2.2 (±0.2) mg/km over the WLTP-Brake and 2.2 (±0.2) mg/km over the 3h-LACT, respectively. The corresponding PM10 emissions were 5.6 (±0.2) mg/km and 8.6 (±0.7) mg/km, respectively. The measurements revealed the formation of nanosized particles peaking at 10 nm, which were thermally stable at 350 °C under both cycles. Volatile nanoparticles were observed over the more demanding 3h-LACT cycle, with their emission rates decreasing with increasing the tunnel flow, suggesting nucleation of organic vapors released during braking as a potential formation process.