International Journal of Integrated Engineering

Numerical Simulation of Different Splitter Angles of a Pelton Bucket to Increase the Power Generated by The Pelton Wheel

2022-06-05T08:53:19+08:00

The efficiency of a Pelton turbine depends mostly on its geometry. A design with suitable dimensions, offers higher generation of energy. However, some of these dimensions are underappreciated because of their low influence. Therefore, this study presents through a recompilation of data, the simulation was developed in ANSYS 19®. The importance of taking in count each parameter of the geometry of a Pelton bucket, analysing in this work the influence of the splitter angle in the force generated by a bucket. Nine geometries of a Pelton bucket are developed with splitter angles between 17 and 25°. The most suitable angle is determined, finding through the simulations that the geometry of 23° generates more force than other geometries. Simplifying the geometry and the mesh can generate faster results, however, exaggerating in the meshing process will affect the reliability of the obtained results.

Effect of Roof Design Configurations On Natural Ventilation with an Obstacle Inside the Building Model

2023-02-02T08:24:33+08:00

Roof shape, roof angle, and internal obstacle are some of the factors that have a substantial impact on building's ventilation performance. However, previous roof ventilation studies have not considered the influence of internal obstacle which can affect the overall building’s ventilation performance. For this study, CFD was used to study the effect of roof design configurations on natural ventilation with an obstacle inside the building model. The numerical simulation was carried out by using steady RANS equation specifically the Standard k-ε with enhanced wall treatment. A total of 40 simulation cases were carried out. The study considered two roof shapes mainly the sawtooth roof and the saltbox roof with varying roof angle which were 10º, 20º, 30º, and 40º. Internal obstacles with various height were further added into the simulation cases. Next, grid sensitivity analysis was carried out using Grid Convergence Index (GCI) and Factor of two of observations (FAC2) analysis was carried out as model verification method to ensure a reliable simulation result. Based on the results, it is found that airflow characteristics such as wind speed, distribution of pressure coefficient, and flowrate of an isolated building are strongly dependent on the roof shape and roof angle. Next, the dimensionless flowrate (DFR) is measured to be highest with largest roof angle while lowest with smaller roof angle. Furthermore, the DFR of a building with internal obstacle is lower than that without an internal obstacle due to blockage of incoming air. Moreover, the results show that the sawtooth roof outperforms the saltbox roof in terms of measured parameter. Finally, the study concluded that an isolated building with higher roof angle and without an internal obstacle leads to the best dimensionless flowrate throughout the building.Roof shape, roof angle, and internal obstacle are some of the factors that have a substantial impact on building's ventilation performance. However, previous roof ventilation studies have not considered the influence of internal obstacle which can affect the overall building’s ventilation performance. For this study, CFD was used to study the effect of roof design configurations on natural ventilation with an obstacle inside the building model. The numerical simulation was carried out by using steady RANS equation specifically the Standard k-ε with enhanced wall treatment. A total of 40 simulation cases were carried out. The study considered two roof shapes mainly the sawtooth roof and the saltbox roof with varying roof angle which were 10º, 20º, 30º, and 40º. Internal obstacles with various height were further added into the simulation cases. Next, grid sensitivity analysis was carried out using Grid Convergence Index (GCI) and Factor of two of observations (FAC2) analysis was carried out as model verification method to ensure a reliable simulation result. Based on the results, it is found that airflow characteristics such as wind speed, distribution of pressure coefficient, and flowrate of an isolated building are strongly dependent on the roof shape and roof angle. Next, the dimensionless flowrate (DFR) is measured to be highest with largest roof angle while lowest with smaller roof angle. Furthermore, the DFR of a building with internal obstacle is lower than that without an internal obstacle due to blockage of incoming air. Moreover, the results show that the sawtooth roof outperforms the saltbox roof in terms of measured parameter. Finally, the study concluded that an isolated building with higher roof angle and without an internal obstacle leads to the best dimensionless flowrate throughout the building.

Aerodynamic Drag Reduction Around Vehicles Using a Curved Deflector

2022-08-30T08:05:40+08:00

A passive flow control on a generic car model was numerically studied. The Ahmed model with rear slant angle of 25° was used to study the aerodynamic effects. The concave deflector was tested for the first time in this paper to minimize the drag coefficient. The deflector was fixed between the end of the roof and the top of the rear window. Simulations were firstly performed for different straight deflector’s length rates based on the length of the model, for Reynolds number Re=7.89×10⁵. A significant drag reduction was observed for the high length rate studied. Secondly, the length rate was fixed, and the deflector was investigated for different curvature radius and inclination angles. It was concluded that the Ahmed model with concave deflector gives the best drag reduction, compared to the model with straight deflector and the model without deflector. It was observed that the installation of a concave deflector on the Ahmed model widen the wake zone and remove the vortices from the rear base. For this case, the lift coefficient was reduced, this improves the stability of vehicle on the road at high speed.

The Effect of Laying Nozzle Distance Position on Operational Results Renewable Power Plant Pico-Hydro

2022-08-24T11:34:04+08:00

New and renewable energy sources today and in the future are human needs that need to be sought and explored from all existing nature, especially in countries with many sources of application, such as Indonesia. Indonesia is an archipelago country that has a vast nature with abundant alternative energy sources such as river flow, irrigation which can be used as a source of energy for pico-hydro power plant. The purpose of this study was to determine the performance of pico-hydro with a test model for the position of nozzle position mounted on the pico-hydro using screw Archimedes turbine. The research method is carried out by direct experimentation from a tool that has been made using water fluid that is circulated continuously as if in actual operating conditions. The results of this research show that the positioning of the nozzle distance as the water output to drive the turbine blades affect operational results obtained. The farther distance from nozzle position to thread, the power and rotation also decrease, on the other hand, if nozzle is too close, the water sprayed by nozzle causes a back force of water so that the results are not optimal. In this research, the greatest power is generated at a nozzle distance of 4 cm, which is 230 Watt at a flow rate of 24 m³/h, and the lowest power is obtained at 44 Watt at flow rate of 2 m³/h where this position is ideal for pico-hydro installation. The best turbine shaft rotation in this study was produced at a nozzle distance of 4 cm which is 195 rpm, in this condition the spray of water flowing out of the tip of the nozzle towards the screw blade of the first part of the turbine which hits the sidelines of the screw occurs without resistance.

Performance of Photogrammetry-Based Makeshift 3D Scanning System for Geometrical Object in Reverse Engineering

2022-09-26T09:54:01+08:00

A three-dimension (3D) scanner is one of the important tools for digital reproduction of physical objects in reverse engineering. In some cases, a makeshift 3D scanner is needed immediately, such as for emergency spare parts reproduction. Thus, this research aims to investigate the feasibility of a low-cost makeshift 3D scanner using a mobile phone and the photogrammetry method in reconstructing digital 3D models of geometrical objects. A focus is given to the dimension accuracy of the reconstructed 3D models, which have been reproduced using images taken by a mobile phone, in comparison with the actual dimension of the scanned test pieces. To do so, four types of actual geometrical test pieces with dimension from 5 to 175 mm had been fabricated using CNC machine. 3D models of each test pieces had been developed using the photogrammetry method and compared with those developed using an industrial-grade high-end 3D scanner. It was found that mobile photogrammetry achieved an average accuracy of 97.2%, with minimum and maximum values of 83.3% and 99.9%, respectively. Geometrical dimensions less than 10 mm tend to have lower accuracy, while it was the opposite for dimensions over 150 mm. Furthermore, the scanning limit for either method was found to be a surface with a small tilting angle (less than 3 degrees). Nevertheless, photogrammetry method in combination with a mobile phone has the potential to be utilized as an alternative of a makeshift 3D scanning system with sufficient accuracy using commonly available tools.

Numerical Study of Ducted Turbines in Shallow Water Environment

2023-01-11T09:26:05+08:00

The development of tidal turbines, particularly for shallow water applications, is still in its early stages. Vertical axis tidal turbines (VATT) are often preferred for shallow water due to the bidirectional nature of tidal currents. Implementing a channelling system around a tidal turbine can significantly stabilise the flow field, increase the current velocity, and enhance the energy efficiency of the turbine. However, there has been limited exploration of using channelling techniques to improve the performance of VATTs in turbid areas. This study employs a numerical analysis using computational fluid dynamics (CFD) to investigate VATTs. The VATT model is represented by a cylindrical object with a diameter and height of 5 meters. The simulation focuses on the wake characteristics and the design of turbine arrays. The Reynolds-Averaged Navier-Stokes (RANS) equations are utilised as flow viscous solvers in ANSYS Fluent, and the effectiveness of the ducts in energy conversion is calculated using the realizable two-layer turbulence model. The primary objective of this study is to examine the impact of converging devices on tidal turbine performance and propose an optimal design for shallow water applications. The proposed ducted design shows an increase in current speed passing through the device by 11.1%. Although the wake generated by the multi-row staggered array layout disperses the flow to the side of the domain, the model demonstrates a 0.9% improvement in velocity magnitude. Conversely, the results for the single-row inline layout indicate the most favorable arrangement for shallow water applications, with a 19.4% increase in velocity magnitude and a shorter wake generation.

Preliminary Study On the Function-Defining 3D Surface Roughness Parameters in Tangential Turning

2023-06-26T10:33:15+08:00

The function-defining three-dimensional (3D) surface roughness parameters (which describe an aspect of the surface quality based on areal topography measurements) are studied on tangentially turned surfaces with different technological parameters in this paper. The 2³ factorial design is applied in the planning of experiments. Two levels of depth of cut, cutting speed and feed were chosen for the comprehensive analysis of the tangential turning process. The values of Core Roughness, Reduced Peak Height, Reduced Valley Depth, Skewness and Kurtosis are measured by the application of a 3D areal roughness measurement machine. Equations were determined for the calculation of the studied parameters according to the factorial design method. The results were evaluated in two steps: first the functional parameters derived from the Areal Material Ratio curve were analyzed, then the Skewness and Kurtosis of the assessed area were studied. It is found that a two-fold increase in the cutting speed decreases the Core Roughness Depth, Reduced Peak Height, and Reduced Valley Depth 2-4-fold. The increasing feed rate lowers the presence of inordinately extremes, resulting in a smoother surface. In the point of view of Skewness and Kurtosis, lower cutting speeds and higher feeds are more favorable.

Experimental Investigation of Diesel-WCOB Engine Performance with A Small Proportion of Ethanol/Isobutanol as A Fuel Additive

2023-06-27T08:25:21+08:00

The globe is beginning to face fast-expanding global warming concerns that require immediate treatment. Biodiesel can be considered the most widely used and versatile sustainable fuel for a variety of uses. Because it is biodegradable, environmentally friendly, and renewable, it offers a viable solution to the looming energy crisis. Waste cooking oil is among the locally available sources that might be utilized as an extra source in different countries at a reasonable cost. Combining used cooking oil and diesel is a viable option for diesel engines because it has been certified for use at blending ratios as low as 20% as a commercial fuel. However, when it comes to fuel additives, the best alternative is to use waste cooking oil at high mixing ratios with diesel to power diesel engines. The goal of this research is to examine the various performance parameters of a diesel engine and the characteristics of biodiesel blended fuels by measuring the specific fuel consumption of the brakes and the thermal efficiency of the brakes and to investigate the impact of isobutane and ethanol additions at rates of 5% and 10% on the properties of the fuel and engine efficiency to enhance the specifications of the blended fuel in high proportions B40. Mixed fuel B40 with 10% ethanol (B40E10) can be used as a highly mixed fuel to enhance diesel engine performance. The density, kinematic viscosity, and flash point of diesel fuel were the lowest and rise with the amount of WCOB in the mixture, while the blended fuel B40 had the greatest value and improved with the percentage of additives. Increases in the proportion of additives also result in a visible rise in the braking force and fuel consumption.

Optimization of Rheology Parameters for Feedstock by Powder Injection Molding (PIM) Via Taguchi Analysis

2023-09-20T16:40:37+08:00

The most critical process in the powder injection molding method is determining the powder/binder rate and its properties. The most important feature that distinguishes the powder injection molding method from other powder metallurgy production methods is its advantage in producing high raw density and complex shaped parts. However, providing these advantages includes a multi-parameter process that directly affects the injection molding parameters and the final part's mechanical properties. In addition, the difficulty of experimental studies causes energy, time, and cost losses in determining the powder/binder rate and rheological properties of the feedstock so that the advantages of the method turn into a manageable disadvantage. This study performed rheology studies for three different feedstocks (PW/CW/SA, PW/PE/SA, and PEG8000/PP/SA). In this context, this paper determined the rheological properties of different feedstocks to take advantage of the Taguchi analysis. Flow behavior index, viscosity and optimum loading rates were determined separately for all feedstocks. The results exhibited the injection molding can be done with the determined best (58% steatite+PEG8000/PP/SA) F3 feedstock by volume. Based on it was found that viscosity and melt flow index were not a problem for injection molding in three different feedstocks used in the result, advantages and disadvantages were observed.

Optimization of Vortex Tube Design and Performance for Cooling Milling Process

2022-08-24T07:44:56+08:00

The manufacturing process is required to improve cleanliness and reduce environmental pollution and the exploration of natural resources is limited. One of the manufacturing processes is machining, especially the milling process. The phenomenon during the milling process friction occurs when the workpiece is cut by the milling tool, the effect friction between tool and workpiece occurs temperature rise. To reduce the temperature rise of the milling tool during the workpiece cutting process, an effective and efficient alternative cooling is needed through the use of vortex tubes. The research method was carried out using the Computational Fluid Dynamic (CFD) approach and experiments with the use of inlet pressure = 1-5 Bar, and the parameters of variations in valve shape, number of nozzles, and pipe lengths. The overall results of the CFD and experiment of parameters in inlet pressure on the number of nozzles, valve shapes, and tube lengths, have an impact on the increasing inlet pressure, the higher the thermodynamic characteristics that occur in the vortex tube, but there is a loss of outlet pressure in each parameter. The geometry of the vortex tube selected is the number of nozzles 6, valve fillet shape, and tube length of 50 mm, vortex tube can be used for cooling the milling tool with the addition of a flexible hose at a distance of 5 cm from the tooltip.

Development of a Filament Extruder Using Flow Theory with the Newtonian Fluid Assumption

2023-01-11T10:40:23+08:00

This article presents an investigation of the flow characteristics of the polymer melt in a single-screw extruder and the design of a filament extruder to verify the above theory. The flow characteristics of the polymer melt in a single-screw extruder are likable to that of a viscous liquid between two infinitely parallel sheets, one moving and the other stationary. An integrated flow equation was then found for a case when the viscosity of a liquid remains constant in an isothermal extrusion. These flow behavior theories were then verified via the design and fabrication of a filament extruder for 3D printers.

Passivity-Based Tracking Control of a Mobile Manipulator Robot

2022-09-25T10:09:04+08:00

This work presents a control approach based on the passivity principle, developed to guarantee performance of the application used to track the trajectory of mobile manipulator when disturbed. By exploiting the particularity of the mobile manipulator robots modelling equipped with a nonholonomic mobile base, we present a global control law for the mobile manipulator as a single system. This control allows taking into account the whole system and modifying its dynamics by introducing a highly non-linear regressor matrix to consider uncertainties and modeling constraints. The presented controller is applied to the mobile manipulator robot composed of a manipulator's arm with 2 DDL mounted on a mobile unicycle platform. Simulation tests validate the performance of the proposed approach when external disturbances occur; showing an acceptable performance of the system's stability and validated by exploiting the Lyapunov theory.

Optimization Study on Carbonization of Palm Kernel Shell Using Response Surface Method

2023-01-11T10:31:38+08:00

The carbonization of Palm Kernel Shell (PKS) was carried out in a constant volume reactor and the optimization of the important factors (Temperature, Particle Size, and Residence time) that affect the quality of the biochar product was investigated using Response Surface Method (RSM-CCD). The characterization results before carbonization show that PKS is a potential biomass to be considered as an alternative for fossil fuel. Center Composite Design (CCD) was employed in the carbonization process to investigate the effect of process parameters on the quality of bio-char formed. The optimized conditions obtained for fixed carbon yield were temperature of 469.16^oC, the particle size of mm, the residence time of 17.68 min, and these optimized conditions gave a fixed carbon of 79.65 % with a corresponding yield of 34.00 % while the temperature was observed to be the most influential factor. The optimized conditions were validated and the predicted results were in good agreement with the experimental results, as the relative error between the predicted and experimental values for the fixed carbon and corresponding percentage yield were -1.26 and 0.36 %, respectively. The study revealed the potential of PKS at different particle sizes considered, to be used as solid fuel.

Grey Based Taguchi Optimization Method for Abrasive Wear Appraisal of Fibre-Reinforced PTFE Composites

2023-09-20T15:35:09+08:00

The current study is aimed at optimizing the abrasive wear property of fibre reinforced polytetraflouroethylene (PTFE) composites. The test was contrived based on Taguchi L9 orthogonal array for the optimization of test trials. To appraise the abrasive wear trend of the PTFE based composites satisfying multi-objective criteria, Taguchi method combined with grey relational analysis (GRA) has been used. Abrasive wear test was performed using pin-on-disc configuration as per ASTM G99 standard involving four process parameters. Analysis of variance was used to establish significant parameters which influence the abrasive wear of PTFE composites. Observation revealed that grit size has the most significant effect on abrasive wear of reinforced PTFE composites. After exhaustive investigation of parameters, optimum combination of parameters was established. Linear regression model was built to predict the optimized conditions. The model as well as the optimum parameter values could be used by the abrasion industries for reduction in the time and cost expanded on wear test thus increasing productivity.

Influence of Design and Cutting Conditions On the Accuracy of the Hole Obtained by Drills with Multifaceted Non-Regrind-Able Inserts (MNP)

2023-01-11T10:21:25+08:00

Drills with MNPs have a fundamental design difference from spiral drills, expressed in increased rigidity of the body, a change in geometry and the absence of a wide gauging part. In this article, taking into account the kinematic cutting angles and the real design of the tool, recommendations are given for determining the maximum allowable feed. The shape of the machined hole is proved to a large extent by the ratio of the angular velocities of the precession of the drill axis and its own frequency of rotation.