Simulation of ant colony optimization on hole making performance

Hole making operation one of machining process widely used in industrial industry. One of the main criteria in determining the efficiency of machining performance in hole making operation is shortest machining time. In this paper, simulation approach based on Ant colony optimization (ACO) has been done on hole making operation in order to minimize the machining time. The result based on ACO has been compared with the result obtain based on Genetic Algorithm (GA). Based on the simulation results, the ACO is enhance the performance of hole making process by reducing 13.5% of machining time. The results show that ACO is capable to minimize the machining time of hole making procees

Effect Of Cooling Rate On Microstructures And Mechanical Properties Of C102 Copper Alloy

The objective of this study is to illustrate the effect of two types of heat treatment on microstructure and mechanical properties of C102 copper alloy. Annealing and quenching were conducted to study the effect of cooling rate on material. Specimens were heated at 350, 400 and 500oC and were cooled by using two types of cooling medium; furnace cooling and water quench. Tensile strength of 254.6 MPa was obtained for the asreceived specimen. It was shown that an increase in cooling rate contributed to a higher strength due to local strain effect. Rapid cooling in quenched specimen had successfully increase the hardness by 41% and recorded the highest tensile strength of 359 MPa while slow cooling rate which experienced by an annealed specimen resulted in the lowest tensile strength of 136 MPa. Microstructure investigation shows annealed specimen produced coarse austenitic structure with larger grain size. Meanwhile, quenched specimen produced finer austenitic structure with smaller grain size. It was observed that the grain size of annealed specimen was increased with soaking temperature, however, quenched specimen shows the other way around

The use of cement leftovers from the hollow of spun piles as an additive in self-compacting concrete

Spun piles have been used widely by developing countries, including Malaysia, to construct the foundation of most construction projects. A spun pile is a reinforced precast and prestressed concrete that is compacted in a mould through spinning compaction. The spinning compaction produces cement leftovers in the hollow part of spun piles that can be added to concrete mixtures as an additive. The cement leftovers of spun piles were used as an additive in cement in range of 0%, 10%, 20% and 30% (equal percentages). The resulting compressive strength after curing periods of 7 days and 28 days were presented to investigate the properties of self-compacting concrete containing cement leftovers from the spun piles. Other properties investigated include the physical properties of fresh concrete and water absorption. The results indicated that higher compressive strength and lower water absorption were achieved by the concrete samples containing cement leftovers compared to controlled concrete

Computational Simulation of Boil-Off Gas Formation inside Liquefied Natural Gas tank using Evaporation Model in ANSYS Fluent

Research on the waste energy and emission has been quite intensive recently. The formation, venting and flared the Boil-off gas (BOG) considered as one of the contribution to the Greenhouse Gas (GHG) emission nowadays. The current model or method appearing in the literature is unable to analyze the real behavior of the vapor inside Liquefied Natural Gas (LNG) tank and unable to accurately estimate the amount of boil-off gas formation. In this paper, evaporation model is used to estimate LNG Boil-Off rate (BOR) inside LNG tank. Using User Define Function (UDF) hooked to the software ANSYS Fluent. The application enable drag law and alternative heat transfer coefficient to be included. Three dimensional membrane type LNG cargos are simulated with selected boundary condition located in the United States Gulf Coast based on average weather conditions. The result shows that the value of BOR agrees well with the previous study done with another model and with International Marine organization (IMO) standard which is less than 0.15% weight per day. The results also enable us to visualize the LNG evaporation behaviors inside LNG tanks

The effect of different aspect ratio and bottom heat flux towards contaminant removal using numerical analysis

Cubic Interpolated Pseudo-particle (CIP) numerical simulation scheme has been anticipated to predict the interaction involving fluids and solid particles in an open channel with rectangular shaped cavity flow. The rectangular shaped cavity is looking by different aspect ratio in modelling the real pipeline joints that are in a range of sizes. Various inlet velocities are also being applied in predicting various fluid flow characteristics. In this paper, the constant heat flux is introduced at the bottom wall, showing the buoyancy effects towards the contaminant’s removal rate. In order to characterize the fluid flow, the numerical scheme alone is initially tested and validated in a lid driven cavity with a single particle. The study of buoyancy effects and different aspect ratio of rectangular geometry were carried out using a MATLAB govern by Navier-Stokes equation. CIP is used as a model for a numerical scheme solver for fluid solid particles interaction. The result shows that the higher aspect ratio coupled with heated bottom wall give higher percentage of contaminant’s removal rate. Comparing with the benchmark results has demonstrated the applicability of the method to reproduce fluid structure which is complex in the system. Despite a slight deviation of the formations of vortices from some of the literature results, the general pattern is considered to be in close agreement with those published in the literature

Effect of Soot Particle Diameter to Soot Movement in Diesel Engine

Soot is one of the end product produced from the combustion of diesel engine. It can adversely affect the performance of the engine. It can cause the lubricant oil to be dirty thus increase its viscosity. These will results to frequent change of lubricant oil. Therefore, the focus of this study is related to the mechanism soot particles movement during the combustion process in the cylinder of diesel engine. The study of the path movement of soot particles from the initial position where it was formed to the last position was carried out. To analyze their movements, the data formation of soot particles was obtained through the simulation of combustion engine using Kiva-3V software which was used in previous investigation. The data that were obtained from the Kiva-3v simulation were velocity vectors of the soot, fuel, temperature, pressure and others. This data is used in the MATLAB routine to calculate the location of soot particles in the combustion chamber. Mathematics algorithm which is used in the MATLAB routine is trilinear interpolation and 4th order of Runge Kutta. In this study, the influence of soot particles diameter with different angular (θ) is included in the calculation to determine its movement. Results from this study shows that if the size of soot particles is bigger, the probability of the movement of soot particles to the combustion chamber wall is high thus contaminating the lubricant oil

Development of a home-based wrist rehabilitation system

There are several factors that may result to wrist injuries such as athlete injuries and stroke. Most of the patients are unable to undergo rehabilitation at healthcare providers due to cost and logistic constraint. To solve this problem, this project proposes a home-based wrist rehabilitation system. The goal is to create a wrist rehabilitation device that incorporates an interactive computer game so that patients can use it at home without assistance. The main structure of the device is developed using 3D printer. The device is connected to a computer, where the device provides exercises for the wrist, as the user completes a computer game which requires moving a ball to four target positions. Data from an InvenSense MPU-6050 accelerometer is used to measure wrist movements. The accelerometer values are read and used to control a mouse cursor for the computer game. The pattern of wrist movements can be recorded periodically and displayed back as sample run for analysis purposes. In this paper, the usefulness of the proposed system is demonstrated through preliminary experiment of a subject using the device to complete a wrist exercise task based on the developed computer game. The result shows the usefulness of the proposed system

Numerical Analysis on the Effects of Cavity Geometry with Heat towards Contaminant Removal

Contaminants are recently discovered at the joint of large piping system and causing defect to industrial product. A computational analysis can be used as a solution of the hydrodynamic contaminant removal without any modification needed. In this paper, the effect of heat is introduced to analyze the heat transfer and flow field in a channel with cavity heated at the bottom sides coupled with different shape of cavity. The cavity shape used comes with three shapes i.e. square, triangle and semicircle. The process of fluid dynamic in a cavity is modeled via numerical solution of the Navier–Stokes equations using Cubic Interpolated Profile (CIP) method. By using the simulation of hydrodynamic contaminant removal, the flow of streamlines and vortices pattern was investigated in the cavities. In order to remove all of the contaminant, hydrodynamic need to take part in this simulation which is flow from the inlet of the channel and create vortices to remove it from the cavities. The result shows that the percentage of contaminant removal is higher for semicircle cavity with higher Grashof number. The result also indicates that vortices formation is highly dependent on the cavity geometry and creates a buoyancy effect

Mini acceleration and deceleration driving strategy to increase the operational time of flywheel hybrid module

This paper presents a new driving strategy to increase the operational time of flywheel hybrid module. The flywheel hybrid module contains low cost mechanical parts which installed on the small motorcycle. Based on normal driving cycles characteristics, the Mini-AD driving strategy is develop. It is involved a series of short or mini acceleration cycle and short deceleration cycle on top of the normal driving cycles. The new strategy is simulated for flywheel hybrid module, aimed for acceleration phase only. Simulations show that the new driving strategy can increase the operational time of flywheel hybrid module up to 62.5%

Gnielinski method in calculating the heat transfer coefficient for metallic solar tower absorber

This work is done to calculate the heat transfer coefficient of metallic wire mesh to air in an open volumetric thermal absorber. It is aimed to replace the actual ceramic with metallic which latter has better thermal properties in order to increase the efficiency of the concentrating solar power plant. The calculation of the heat transfer coefficient from porous wire structure to the air has been conducted to pursue the purpose. The structure that has been chosen is a set of metallic wires with aligned and shifted configurations. The variations of wire diameter together with various porosities from 0.10 to 0.50 have been calculated to obtain the best configuration for the absorber. The flow characteristic within the mesh structure in terms of Reynolds number and its relationship with the heat transfer coefficient has been obtained. The condition on mass flow rate of heat transfer medium and other aspects which influence the heat transfer are also discussed