Higher Rpm Research Articles

Development of Bamboo Based Nylon 66 Composite through Friction Stir Processing-An Attempt

The concept of developing a bamboo-based Nylon 66 polymer matrix composite is a relatively novel and very new technical attempt through friction stir processing (FSP). This innovative approach can create a composite material that strengthen the mechanical properties of bamboo and the versatility of Nylon 66. However, successful implementation requires careful consideration of FSP process parameters such us tool rpm, traverse speed, tilt angle and tool design. Among the processing parameters, the tool rpm shows the significant role for severe plastic deformation and temperature generation which leads to the achieving excellent bond. Therefore, in this present study attempt has made to develop the polymer matrix composite (nylon 66 and bamboo powder) using FSW process at a variant rotational speed of 300,400 and 500 rpm with the constant traverse speed of 25 mm min-1. The deformation behavior and the peak temperature evolved under the tool shoulder during the stirring motion is studied using COMSOL Multiphysics simulation. It is found that, the specimen processed with higher rpm (500rpm) shows the higher volumetric strain and the peak temperature and it is evident that with increasing rpm the higher amount of severe plastic deformation occurred. Initially the process parameters are optimized without bamboo powder on the nylon 66 plate of 6 mm thickness and found that the 500 rpm processed specimen shows the defect free. Prior to the actual FSP, the small keyways taken on the center of the nylon 66 plate in order to add the bamboo powders in it. Actual processing was done with bamboo powder after adding natural bamboo powder of size 50µm. The result reveals that, the bamboo powder has partially expelled out during the period of FSP. This complete study concedes that the processing parameters needs to be optimized and also bamboo added method need to be studied for the successful development of bamboo-based polymer matrix composite.

Feasibility study on the heat transfer enhancement of gap flow induced by wasted vibration of linear compressor body

Refrigerators account for 20–30 % of household electricity consumption, with the compressor contributing to 80 % of the total consumption. Therefore, it is essential to increase the compressor efficiency. One approach to enhance compressor performance involves increasing heat dissipation to lower the temperature of the suction system and boost the refrigerant density entering the suction chamber. To achieve that innovatively, we harnessed the waste vibration of the linear compressor body to create a gap flow between the body and the housing, enhancing compressor performance by augmenting heat dissipation. Measurements of gap flow temperature, cylinder surface temperature, and heat flux on the cylinder surface were conducted, varying the RPM, gap size, and the shape of the gap flow path. We also observed variations in the gap flow rate with RPM and stroke. The results revealed that gap temperature and heat flux increased with higher RPM and smaller gap size, and the application of ribs to the gap flow path proved to be more effective in enhancing temperature and heat flux. Additionally, it is anticipated that heat flux will further increase with a longer stroke as the flow rate increases. Therefore, to optimize heat dissipation through gap flow using the waste vibration of the compressor body, it is advantageous to employ a smaller gap size, higher RPM, longer stroke, and apply ribs to the gap flow path. Future research should focus on verifying the effectiveness of increased heat dissipation and improved Energy Efficiency Ratio (EER) through actual compressor experiments.

CFD Modelling of Swirling Mechanism to Reduce Erosion of Pipe Bend in Pneumatic Conveying System

Dry powders mixed with air transportation had bend erosion issues. CFD analysis by Shear-Stress Transport (SST) k-ɯ Model within Ansys was used to conduct a comprehensive numerical analysis of particle erosion within a 90° mild steel pipe bend in Pneumatic Conveying System. Part of the conveying pipe rotation achieved with the external motor swirling device was used to create swirling of particle before bend. Different-sized sand particles at different rpm were tested with and without a swirling device. Reduction in erosion rate of pipe bend carries significant implications, notably an extension of the system's operational lifespan. Reduction in erosion rate reports an impressive increase of 50% bend lifespan at higher RPM levels of the swirling device. The results underscore the effectiveness of this device in mitigating erosion, with significant implications for enhancing the longevity and reliability of bend life in piping systems of Pneumatic Conveying applications.

Влияние геометрии наконечника сварочного инструмента на характеристики растяжения соединений сплава АА8011, полученных сваркой трением с перемешиванием

Introduction. Aluminum alloys are in abundant demand of shipbuilding and aircraft industries. This study emphasizes on the effects of two different tool pin profiles on the tensile characteristics of welded joints made of AA8011 aluminum alloy welded joints. The joining technique used is friction stir welding (FSW) due to its unique characteristics such as very low heat affected zone when joining in a solid state. The microstructure and mechanical properties of the welded joint are influenced by the geometry of the tool and such parameters as rotational speed and traverse speed of the tool. The methods of investigation. The experiments on FSW were performed on universal milling machine with taper cylindrical and cylindrical threaded tool pin profiles using the three different combination of tool rotational and traverse speed (a) 320 rpm, 45 mm/min; b) 400 rpm, 50 mm/min; c) 575 rpm, 60 mm/min.). To analyze the joint characteristics, tensile tests were conducted and ultimate tensile strength as well as joint efficiency was calculated for individual joint. Results and Discussion. Based on the revised results, it is evident that higher RPM values have a positive impact on joint efficiency and tensile strength for both the taper cylindrical pin profile and the threaded cylindrical pin profile. The findings show that the joint efficiency and tensile strength are consistently higher for the threaded cylindrical pin profile compared to the taper cylindrical pin profile, regardless of the RPM and feed rate. From the results, it was found that joint efficiency and tensile strength is maximum at higher RPM irrespective of the tool pin profile i.e. 73.6 % and 123 MPa for taper cylindrical pin profile and 85 % and 142 MPa for threaded cylindrical pin profile at 575 rpm, 60 mm/min. These are the highest in comparison to 72.5 % and 119 MPa at 320 rpm, 45 mm/min and 70.1 % and 115 MPa at 400 rpm, 50 mm/min for taper pin profile tool and 82.6 % and 138 MPa at 320 rpm, 45 mm/min and 77.8 % and 130 MPa at 400 rpm, 50 mm/min for threaded cylindrical pin profile. Overall, the study demonstrates that joints obtained using the threaded cylindrical pin profile demonstrate higher joint efficiency and tensile strength than those prepared using the taper cylindrical pin profile. The highest joint efficiency and tensile strength of 84.5 % and 142 MPa, respectively, were achieved using the threaded cylindrical pin profile at 575 rpm and 60 mm/min.

Aerodynamic Analysis of Mathematically Modelled Propeller for Small UAV Using CFD in Different Temperature Conditions

Unmanned aerial vehicle (UAV) usage has witnessed a significant rise owing to its cost-effectiveness and versatile applications. However, the design techniques for UAV propellers, encompassing aerodynamic and structural analysis, have received limited attention from researchers. A well-designed propeller can effectively reduce battery consumption and enhance overall efficiency. This study focuses on mathematically designed propellers and compares them with advanced precision composite (APC) Slow Flyer propeller blades in terms of thrust coefficients, power coefficients, and efficiency. The investigation includes the utilization of tetrahedron meshing in simulations, employing the standard k–ω (k–omega) model. To evaluate the accuracy of the blade element theory (BET) in predicting thrust, the simulation data is compared with BET results. Furthermore, the study encompasses experimental testing to validate the simulation findings. The findings demonstrate that the mathematically modelled propeller outperforms the APC Slow Flyer propeller across all ranges of revolutions per minute (rpm). When comparing the results of both methods, BET exhibits an error difference of 10 % in higher rpm ranges, but this error diminishes as the rpm decreases. This study contributes a novel design technique for modelling propellers using mathematical formulas and provides a comprehensive comparison of their aerodynamic properties with existing propellers, utilizing both BET and computational fluid dynamics (CFD) methods, along with experimental validation.

Agitation role (Dissolved Oxygen) in production of laccase from newly identified Ganoderma multistipitatum sp. nov. and its effect on mycelium morphology

BackgroundAgitation speed influenced the production rate of laccase. Orbital speed not only influenced the enzyme production, but was also effective to dissolve the oxygen during growth of mycelium, spores, and chlamydospores. Shear effects of speed greatly influenced the morphology of mycelium.MethodsGanoderma multistipitatum was identified by ITS marker. Phylogenetic tree was constructed for species identification. Qualitatively by plate method contained guaiacol indicator, while quantitatively by submerged fermentation and Central Composite Design applied on agitation parameter for maximum laccase potential of this species. The effects of agitation speed on mycelium morphology were observed under compound and scanning electron microscope.ResultsStatistical optimization of agitation conditions were performed by using response surface methodology to enhance the production of laccase from Ganoderma multistipitatum sp. nov. Maximum laccase yield (19.44 × 105 ± 0.28 U/L) was obtained at 150 rpm grown culture, which was higher than predicted value of laccase production (19.18 × 105 U/L) under aerobic conditions (150 rpm). The 150 rpm provided the continuous flush of oxygen. The DO (dissolved oxygen) was maximum (65%) for “27 h” incubation at 150 rpm during laccase synthesis. The statistical value of laccase production was minimum under anaerobic or nearly static condition of 50 rpm. The predicted (12.78 × 105 U/L) and obtained (12.82 × 105 U/L) yield was low at 50 rpm. Optimization of orbital shaking for aeration conditions were performed by the use of “Response Surface Methodology”. The submerged shaking flasks were utilized as a nutrients growth medium to maximize the production of laccase from G. multistipitatum. The minimum incubation time highly influenced the laccase yield from 7 to 15 days via utilization of less cost-effective medium under a promising and eco-friendly method. The morphological effects of rpm on mycelium were examined under compound and scanning electron microscopy. Higher rpm (200, 230) shear the mycelium, while 150 to 200 rpm exhibited smoother and highly dense branches of mycelia.ConclusionThe shear forces of 200 rpm caused the damages of mycelium and cells autolysis with less laccase production. This study concluded that 150 rpm saved the life of mycelium and enhanced the production rate of enzymes.

Effects of Drilling Parameters and Mud Types on Wear Factors and Mechanisms of SM2535 Casings

This work aims to explore the impact of side loads, drill-pipe tool-joint (DP-TJ) speed (rpm), and mud type on the austenitic stainless steel SM2535-110 casing wear characteristics. Actual field drill pipe tool joints, casings, and drilling muds are used in this study. The results of the study show that under both types of lubrication, the wear volume increased with radial load and DP-TJ speed. SM2535-110 casing specimens tested under oil-based mud (OBM) lubrication had higher casing wear volumes than those obtained under water-based mud (WBM) lubrication. This unexpected behavior is mainly due to the increase in the surface hardness of the casing specimens tested under WBM. The results also show that the specific wear rate or wear factor (K) (which is defined as the volume loss per unit load per unit distance sliding) values of specimens tested under WBM are in general two to four times higher than those obtained under OBM. While K values under WBM increase with both the side load and rpm, those under OBM show a sharp decrease with rpm. This behavior under OBM is due to this lubricant’s higher viscosity and the change of lubrication regime from thin film to thick film lubrication at higher rpm. Scanning electron microscopy (SEM) and the digital microscopic imaging (DMI) of SM235-110 casing specimens show that an aggressive combination of adhesive, abrasive, and plastic deformation was observed under WBM, while the dominant wear mechanism under OBM is abrasive wear.

Pengaruh Penggunaan CDI Standar Dan CDI Digital Terhadap Daya Dan Torsi Motor Bensin 250CC

As with the engine ignition system, the spark produced by the manufacturer's standard CDI is limited or known as a CDI limiter, in contrast to non-limiter CDI which has no limits or has a higher spark limit on the engine so that it can produce engine performance up to a higher RPM. higher and produces maximum engine performance. Weaknesses in the factory standard CDI can be overcome by replacing it with a racing CDI. Racing CDI has the same quality or even better than standard CDI. Racing CDIs are made by local manufacturers and from abroad and are now easily available in spare parts stores or motorbike repair shops throughout Indonesia.

Experimental investigation on turbulence effects on unsteady aerodynamics performances of two horizontally placed small-size UAV rotors

Wind turbulent disturbance is one of the critical challenges to flying unmanned aerial vehicles (UAVs); especially when the size, weight, and power on board such aircraft are limited. Therefore, to shed light on such turbulent wind effects on UAVs' aerodynamic performances, wind tunnel experiments were conducted on the single- and multi-rotor configurations by varying the turbulence intensity up to 15%, while setting the wind velocity at 5 m/s. The turbulent disturbances were generated inside the wind tunnel using two different passive grids. One is with 29% blockage, and the other is 49%. As the single-rotor experimental tests were conducted, the onset turbulence was found to give rise to a significant change in thrust and the power coefficient in the presence of a lower revolution per minute (rpm). However, at higher rpm, only the wind effect is observed to be the dominant contributor to the aerodynamic performance. Additionally, three different rotor spacings are experimentally examined to measure the propeller wake interactions at the same velocity and different onset turbulence intensities. It was experimentally found that a significant wake interaction occurs between 0.5 D (diameter) and 1.25 D below the propellers, depending on the rotor spacing and the flow conditions. The present work opens up an experimental approach to examine the unsteady aerodynamic performance of multi-rotor UAVs in the presence of wind disturbances, i.e. at different turbulence intensities.

Analysis of the Use of CDI Variations with Fuel Variations on the Power and Torque of a Single Cylinder Gasoline Motor

This research aims to determine the ratio of power and torque produced by motorcycle engines using CDI variations with various fuels. The type of research used is descriptive quantitative. Data collection techniques using tests, namely by testing the object under study then measuring and recording directly the resulting data. The testing process uses the help of a dynamometer measuring instrument. Data collection was carried out at 6000 to 11000 rpm rotation. The results showed that the power and torque produced using standard CDI DC on pertalite fuel showed the lowest value with a maximum power of 22.5 HP at 9168 rpm and a maximum torque of 19.78 Nm at 6576 rpm, on Pertamax 92 fuel the maximum power was 22, 6 HP at 8370 rpm, with a maximum torque of 19.99 Nm at 7246 rpm and the Pertamax 98 fuel shows the highest value with a maximum power of 23.2 HP at 8931 rpm and a maximum torque of 20.16 Nm at 7345 rpm. For the power and torque generated by the use of CDI DC racing BRT on pertalite fuel, it shows the lowest value with a maximum power of 22.9 HP at 8604 rpm and a maximum torque of 19.43 Nm at 7670 rpm, on Pertamax 92 fuel the maximum power is 23, 6 HP at 8979 rpm, with a maximum torque of 19.81 Nm at 7552 rpm and the Pertamax 98 fuel shows the highest value with a maximum power of 23.8 HP at 9156 rpm and a maximum torque of 20.36 Nm at 7458 rpm. The use of CDI DC racing BRT is able to serve engine performance at higher rpm rotations and produce greater power and torque for each type of fuel variation.

Experimental study on the quality of drilled holes in Sabai grass reinforced composites

Hole quality in composites plays very important role in the production of close tolerance holes in automobile parts. Through drilling experiments in Sabai Yarn reinforced composite, this study examines the impact of different input parameters like feed rate, rpm, and tool diameter. The circularity of hole was measured with the help of CMM. The circularity error was reported in the range of 0.037 to 0.1628 mm. Design of experiments and Taguchi method have been used to study the effect of process parameters. The circularity of hole mainly depends on feed rate and rpm in the drilling process of Sabai yarn composite. The circularity error and delamination are minimum in treated reinforcement in yarn (0°) and woven yarn (0°/90°) compared to the untreated reinforcement yarn (0°) and woven yarn (0°/90°). Due to strong bound strength fibres cannot pull-out its cut with tool edge so that it gives smooth machined surface in treated reinforcement. The chip formation in drilling depends on the feed rate and tool diameter. Chips are discontinuous at the higher feed rate and higher rpm.

THE USE OF A CAR WINDSHIELD RUBBER BLADE TO MAKE A MOTORIZED WHITEBOARD ERASER

Innovation from scrap materials can go beyond expectations. For this reason, the objective of this study is to create a motorized whiteboard eraser out of a car windshield rubber blade from a broken car. With the help of Arduino Uno and Arduino Interface, an open-source electronics platform based on easy-to-use hardware and software, was able to help read the coding and inputs in causing the wiper move with a switch, battery and motor. The results of the study showed that the time of executing the command was 0.35 seconds after turning the switch on, while the distance covered in centimeters by the motorized whiteboard eraser was 75cm. It is also noted that after four rounds of horizontal swiping directions it had totally erased the writings on the whiteboard. Further, in terms of the speed of erasing the writings, the shortest time was 0.0852 miles per hour. Proving its efficacy on erasing various percentages of shaded parts it is recorded that in 50% shaded part it took a minute and six seconds, while in 75% shaded part it took one minute and 20 seconds, lastly, in a 100% shaded it could totally be erased in a span of one minute and 36 seconds. As a result, it is recommended to increase the speed of the motorized whiteboard eraser by utilizing a bigger motor with a higher RPM capacity. Moreover, it is advised that the whiteboard eraser be improved in order for the rubber blade to entirely adhere itself to the whiteboard in order to have less constraints on erasing. It is also recommended that you choose a lighter material than PVC in order for the eraser to operate smoothly.

Evaluating the combustion performance of plastic oil in an Otto engine: A comparative analysis with premium fuel

This study examines the performance evaluation of plastic oil combustion compared to premium fuel in an Otto engine, focusing on the application of pyrolysis technology for converting plastic waste into oil. The analysis considers parameters such as the lower heating value (LHV) of the fuels, combustion characteristics observed through spark plug electrode examination, RPM requirements for power output, torque generation, and specific fuel consumption (SFC). The results show that plastic oil derived from PP has a slightly lower LHV compared to premium fuel. Visual inspection reveals cleaner combustion with plastic oil, indicating potential advantages in terms of reduced carbon build up. The engine requires a higher RPM to achieve the same power output with plastic oil compared to premium fuel. However, plastic oil generates higher torque at the same power output, suggesting better combustion efficiency. The SFC is highest for premium fuel under low-load conditions. The findings underscore the potential of plastic oil as a sustainable and environmentally friendly alternative fuel, derived from the conversion of plastic waste using pyrolysis technology. Further research and optimization are needed to enhance the fuel quality and overall performance of plastic oil.

Characterization of the Propulsion System for Submersible Multimedium Robotic Vehicles

Multimedium robots are a new class of bioinspired vehicles with the ability of cross-domain transition and maneuverability across multiple domains. Such hybrid robots can transverse both in air and water, overcoming the stark differences in the motion dynamics within these mediums. Differences in the density, viscosity, and additional fluid-induced forces of the medium make the propulsion system design for multimedium robots a crucial challenge. Both unmanned aerial and remotely operated underwater vehicles rely on electrical propulsion coupled with propellers to navigate in their own respective medium of operation. However, due to the density differences in water and air, which is approximately 103 times, an aerial propeller demands higher RPM to generate significant thrust, unlike an underwater propeller. Higher water density and fluid inertia, on the other hand, demand a greater in-drive torque to spin the propeller in underwater conditions. Other critical parameters to be considered while choosing a suitable propulsion system are propeller diameter, propeller pitch, shaft torque requirements, operational RPM of motor–propeller pair, cavitation, and propeller tip deflection. This article presents an in-depth investigation and evaluation methodology to identify the feasible operating range for propellers and motors that meet the aerial and underwater thrust requirements while minimizing cavitation and propeller deflection. The thrusters (motor-propeller pair) are investigated individually, where propeller performance and physical constraints on the propeller blade are analyzed using blade elemental momentum theory (BEMT), while the motor is studied using the three-constant motor model. These subsystems are then mapped using torque equilibrium to determine their specific operational regime and overall efficiency. Numerical simulation in QPROP demonstrates that aerial thrusters can be utilized for both the mediums but with a sacrifice of overall efficiency. The optimal motor efficiency was 73.06% in aerial operation and 8.1% in underwater operation, but with increased thrust underwater due to higher fluid density, which is essentially a design tradeoff. The results of the analysis are experimentally validated and further presented as a framework for selecting an appropriate propulsion subsystem for multimedium vehicles based on the specific user-defined design requirements.

Simple Floating Ocean Wave Energy Converter: Developing Teaching Media to Communicating Alternative Energy

Research aims to develop teaching media in communicating alternative energy to students who are in high school. The teaching media developed as a prototype converter of ocean wave energy into electrical energy. This Converter is focused on helping students understand concepts and technologies in utilizing ocean wave energy as an alternative energy source. The development stage adopted the ADDIE model, which is limited to the analysis, design, and development stages. The data obtained are in the form of design validation data, trial data, and product assessment data. The data were analyzed using descriptive statistics. Based on the results of data analysis, it is found that (1) the converter design is feasible to be developed with a few additions to the transmission section to produce higher RPM; (2) the resulting converter functions correctly with the output voltage of 5 to 9 volts in the artificial wave pool test and reaches 8 to 12 volts; (3) for product assessment, it was found that the Converter produced was suitable to be used as a teaching medium to communicate concepts and technology in utilizing ocean wave energy as an alternative energy source. So, teaching media in the form of a wave energy converter could be used as an alternative to communicating the concept of using ocean waves as an alternative energy source. The implication of this research is that it can be used as a model or initial example in developing learning media related to alternative energy and can even be used as a model in developing converters on a larger scale so that the wider community can use them.

From the President andIFSTNews

From the President and<scp>IFST</scp>News

Effect of high shear homogenisation on physicochemical, microstructure, particle size and volatile composition of residual pineapple pulp

SummaryWaste or by‐product utilisation is on focus to reduce the environmental threat and acquiring wealth out of waste. This study was planned to understand the effect of high shear homogenisation (SH) on physicochemical, microstructural, particle size, dietary fibre and volatile composition of residual pineapple pulp (RPP) for its utilisation. Shear homogenisation with three levels of rotor speed, that is 5000, 15 000 and 30 000 rpm, was employed for 5, 10 and 15 min. These responses reveal that the shear speed of 15 000 rpm for 10 min was relatively better in colour retention and enhanced soluble dietary fibre (SDF) by 48%. Increased levels of SDF after treatment help in the utilisation of RPP and its suitability for food supplementation. A gradual reduction in particle size from 40 to 400 μm was observed with shear homogenisation. Optical microscopy images revealed that larger cell fragments, fibrous nature and dense hairy mass of pomace were disrupted at 15 000 rpm. Moderate shear speed triggers the release of additional aroma volatiles, whereas higher rpm and time resulted in degradation of volatiles. The shear homogenised RPP is used for the development of fibre‐enriched yoghurt and incorporation at a 5% level resulted in high acceptable sensory scores.

PENGARUH PENGGUNAAN MODE ALTITUDE MODE 2 DAN MODE 3 SEPEDA MOTOR BEAT 2018 FI PADA KETINGGIAN 0-1000 MDPL TERHADAP EMISI GAS BUANG

In testing the effect of using altitude mode 2 and mode 3 Beat Fi motorcycles at an altitude of 0-1000 MDPL on exhaust emissions, this study uses descriptive data analysis methods. The results of the HC test in Mode 1 get the highest results at RPM 3000, which is 481 ppm, while the lowest results at RPM 1000 are 229 ppm. In Mode 2, the highest result is obtained at RPM 3000, which is 1074 ppm, while the lowest result is at RPM 1500, which is 349 ppm. In Mode 3, the highest result is obtained at RPM 2500, which is 1052 ppm while the lowest result is at RPM 1500, which is 468 ppm, while in CO testing in Mode 1, the highest result is obtained at RPM 3000, which is 5.27%, while the lowest result is at RPM 1000, which is 1, 04%. In Mode 2, the highest result is obtained at RPM 3000, which is 6.71%, while the lowest result is at RPM 1000, which is 2.37%. In Mode 3, the highest result is obtained at RPM 3000, which is 8.16%, while the lowest result is at RPM 1500, which is 2.96. From this explanation, it can be concluded that the effect of using mode 2 and mode 3 at an altitude of 0 - 1000 MDPL in mode 2 is that the higher the rpm, the higher the HC and CO levels, while in the higher rpm mode, the HC and CO levels decrease at 3000 rpm.Keywords: Altitude Mode, Exhaust Emissions

A novel approach of harvesting concentrated plasma-rich fibrin (PRF) with increased platelet count

Objectives: Platelet-rich fibrin (PRF) is an autogenous biomaterial, considered as the second-generation platelet concentrates rich in blood cells and growth factors entrapped in the fibrin matrix, which makes it as an ideal material with wound healing abilities. Studies have reported high harvest of cells using anticoagulants but the present study employs two different protocols to efficiently separate the platelet-rich layer at low centrifugal forces without the use of anticoagulants. Material and Methods: Blood samples were collected with the consent of 20 volunteer donors. Ten blood samples were tested in each of the protocols studied, that is, protocol 1–200 g for 8 min (higher rpm and time) and protocol 2–60 g for 5 min (lower rpm and time). From the 12 ml of blood samples collected, 2 ml of blood was utilized for whole blood study; the remaining 10 ml was transferred into falcon tubes subjected to different rpm. Results: The present study employs a novel method to investigate segregation of cell types following low-grade centrifugation. One milliliter sequential pipetting technique was used to analyze number of leukocytes and platelets following centrifugation at two different g-forces. The protocols followed in the present study had 2–3-fold increase leukocytes concentration and 10–12-fold increases in platelet concentrations in the layers than the whole blood sample without the use of anticoagulants. Conclusion: The study concludes that protocol 1 was more efficient in harvesting platelets with less concentration of leukocytes, which is considered more suitable for various medical applications.

CFD investigation on the performance analysis of Tesla turbine

A Tesla turbine is a bladeless turbine in which fluid flows in the direction of the centripetal path. It uses fluid properties such as Boundary layer & adhesion of fluid on a series of discs keyed to a shaft. The initial cost and maintenance cost of the Tesla turbine is very low. Our project’s main motive is to improve the performance of a Tesla turbine by changing various parameters such as disc diameter and disc rotating speed through the CFD simulation software using water as a working fluid. The CAD model is designed using Ansys design modeler, meshing is performed using Ansys meshing and post processing is carried out in Ansys fluent. The numerical simulations were carried out using Ansys Fluent which is based on the finite volume method and the changes that occurred in the pressure and velocities are investigated. The parametric study is performed by varying the turbine disc speed. By performing CFD simulations, total pressure contour and velocity magnitude contours are plotted and it is found that pressure and velocity are maximum when the clearance between disc and turbine casing is lesser and at higher turbine disc speeds. The power output of the Tesla turbine is also plotted for various rpm where higher rpm gives maximum power output. The results from the present study would be useful in designing an efficient Tesla turbine with improved performance.