Papers by NATRAH BINTI KAMARUZAMAN FKM
Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, Aug 13, 2022
The number of words should not exceed 350 Self-powered infusion micropump is a non-mechanical mic... more The number of words should not exceed 350 Self-powered infusion micropump is a non-mechanical micropumps for microfluidics application. A three-dimensional (3D) printing is an intelligent additive manufacturing technique that permits cheap, fast and accurate geometrically complex designs. In this study, a self-powered infusion micropump master mould was fabricated using stereolithography (SLA) 3D printing technique and was characterized accordingly. Furthermore, polydimethylsiloxane (PDMS) self-powered micropump from the 3D printed mould was successfully replicated using soft lithography technique. Optical microscope with i-Solution Lite imaging software was used for micropump mould dimensions characterization. It was found was that the smallest average percentage difference of 4.26 % was measured for straight inlet channel's width between the actual mould and the computer-aided design (CAD). The average coefficient of variance (CV) for all micropump components dimensions was 3.22. It was found that the SLA 3D printing reduced manufacturing time and costs by 30.43 % and 82.84 % respectively in comparison to the standard SU-8 mould. In conclusion, SLA 3D printing technology is a viable alternative to master mould fabrication in self-infusion micropump production since it accurately reproduced the design from the CAD input.
Numerical investigation of drag force on micro-sized magnetic beads in microchannel with chamber design
Biological cells or bioparticles separation is a primary step in most biological studies. One of ... more Biological cells or bioparticles separation is a primary step in most biological studies. One of the microfluidic bioparticles separation methods is the magnetic-based method. Integrated microfluidic magnetic bioparticle separation device is made up of a microfluidics channel and a magnetic system. From past studies, the design of the microfluidic channel is least discussed in comparison with the magnetic system. To fill this gap, this study has focused on numerical simulation of a microfluidic channel with chamber design and the drag forces experienced by the magnetic beads. Simulation of the microfluidics channel was done with ANSYS Fluent software. The width ratios of trapping chamber and main channel ranged from 1 to 20, the flow rates ranged from 1 μL/min to 100 μL/min, and the bead sizes ranged from 5 μm to 25 μm were used in the numerical investigation. It was discovered that as the width ratio between the trapping chamber and main channel increases, the maximum velocity decreases, causing the Reynold's number to decrease. The pressure drop become greater at higher flow rate. Higher width ratio caused the drag force to reduce at a constant microbead size. At a constant width ratio between the trapping chamber and main channel, larger microbead sizes caused larger drag force. The microfluidic system with width ratio of 20 and flow rate of 1 μL/min produced the lowest drag force, 3.64 x 10 4 pN. Since particle trapping would occur when the magnetic force is larger than the drag force, therefore a high gradient magnetic system which offered high magnetic force was proposed to be integrated with the microfluidics system
The objective is to investigate the influence of singularity created by the internal geometry of ... more The objective is to investigate the influence of singularity created by the internal geometry of the double scarf joint, on the damage evolution to the adhesively bonded joint. Several finely instrumented tests are carried out to characterize the damage process unlike the ultimate failure of the adhesively bonded joint. The approach is to compare the micromechanical behavior of adhesively bonded scarf joint and double scarf joint, with the same scarf angle value. Experimental results are obtained by strain gauge measurements to distinguish three damage thresholds, which characterize the damage evolution of the adhesively bonded joint. Numerical results use a damage criterion in order to predict progressive damage evolution. The numerical results show the viability of the failure criterion and the complementarity between experimental and numerical works allows refining our final conclusions.
A Microstructure Device for Single Phase Surface Cooling
ASME/JSME 2011 8th Thermal Engineering Joint Conference, 2011
A microstructure device for cooling of hot surfaces at liquid single phase laminar flow is presen... more A microstructure device for cooling of hot surfaces at liquid single phase laminar flow is presented. The initial design as well as the theoretical background is described in detail. It consists of numerous short micro channels acting as overflow structures and providing a relatively large hydraulic diameter, used in parallel between large inlet and outlet channels. The design was chosen to be scalable as well as appropriate for mass production in different materials. The fluid distribution was optimized as well as the dimensions of the overflow structures in terms of heat transfer, both by CFD simulations. Several devices were tested. They provide very high heat flux at reasonably low pressure drop. The temperature difference to achieve, heat flux and pressure drop can be adjusted easily by control of the applied mass flow. The design was tested as liquid-liquid heat exchanger in a simple lab-scale test facility. Moreover, using a copper electrically powered surface heat focus, some devices were tested as surface coolers.
Journal of Advanced Research in Applied Mechanics, Jan 15, 2022
Miniaturization and utilization of low-dimensional structures of recent electronic devices have w... more Miniaturization and utilization of low-dimensional structures of recent electronic devices have witnessed some new micro cooling methods which can fulfil the cooling demand for the electronic devices. Microchannel heat sink (MCHS) is one of the micro cooling method which appears as a promising method that can provide high heat transfer rate due to small hydraulic diameter. Furthermore, microchannel heat sink is easy to be fabricated compare to other micro cooling device. Due to fast development in electronic industry, hybrid microchannel heat sink with optimal design has received a great deal of attention in order to provide sustainable cooling solutions. However, most of the studies of hybrid microchannel heat sink only provided the numerical analysis without any validation of the proposed design experimentally. This is very important since it also will determine whether the proposed hybrid microchannel heat sink can be fabricated or not. Therefore, the aim of this article is to validate the numerical model of hybrid microchannel heat sink (TC-RR-SC MCHS) experimentally. The validation result showed that the maximum discrepancy between both simulation and experimental analyses for Nusselt number and friction factor were 15.8% and 17.4%, respectively, which is less than 20%.
Flow Visualization of Flat and Curved Trapezoidal Winglet Vortex Generator in Fin-and-Tube Channel in Inline Arrangement
International Review of Mechanical Engineering-IREME, Feb 28, 2017
In this study, a flow visualization experiment using the dye injection technique was conducted. V... more In this study, a flow visualization experiment using the dye injection technique was conducted. Visual observation of the flow characteristics across the scaled up fin-and-tube heat exchanger (FTHE) channel model with and without trapezoidal winglet vortex generator (TWVG) were presented. Four cases of FTHE channel in inline tube arrangement were examined with TWVG at different geometries and arrangements, as well as a case without the vortex generator. The two TWVG geometries used in this study were a flat trapezoidal winglet (FTW) and a curved trapezoidal winglet (CTW) either arranged in common flow up (CFU) or common flow down (CFD) compositions. The Reynolds number (Re) used ranged from 500 to 2500. It was found that with the introduction of TWVG in the FTHE channel, the wake region size behind tubes reduced compared to the baseline case. However, the formation of an additional wake region behind the TWVG was also observed.
Zero-dimensional model for the prediction of carbon nanotube (CNT) growth region in heterogeneous methane-flame environment
Carbon Letters
Strategic Planning for Energy and the Environment
Energy-efficient measures are being increasingly implemented in the building sector to reduce the... more Energy-efficient measures are being increasingly implemented in the building sector to reduce the increasing energy consumption with the growing population and the rapid development of urban building layouts. In hot and humid climates, energy-saving measures for the building envelope elements have attracted increasing interest in research and practice due to their effectiveness in upgrading the building energy performance by reducing the amount of heat gain and solar glare to the building’s indoor environments. Accordingly, as evidenced by our review of the literature, an increasing number of publications on energy-saving measures for the building envelope are being published in peer-reviewed articles. However, a few literature overviews covering all possible energy-saving measures of building envelope elements, which can provide insight into determining the value of their effective parameters to achieve the best performance and evaluate the feasibility of energy efficiency improvem...
Pragmatic Retrofitting Approach to Enhancing the Thermal, Energy, and Economic Performance of an Educational Building: A Case Study in Malaysia
Building retrofit procedures play a crucial role in improving the energy performance and economic... more Building retrofit procedures play a crucial role in improving the energy performance and economic indicators of a building. In this context, an energy audit is typically recommended, but it is seldom used as a comprehensive approach due to the complexity and associated costs. This article aims to conduct a holistic energy audit approach for a university building in Malaysia, with the objective of diagnosing energy efficiency deficiencies, identifying areas of energy waste and proposing practical retrofit measures accordingly. The approach involved multiple stages, including measurements, surveys and simulation work. Eight energy-saving measures were proposed, targeting improvements in envelope elements, cooling and lighting systems, and operation and control. The Design-Builder software was utilized for energy simulation, assessing the annual energy savings. Economic evaluation indices, such as net present value and simple payback period, were used to assess the economic feasibility of the measures. The results demonstrated significant potential for energy reduction, with each measure achieving annual energy reductions ranging from 2% to 18%, and a cumulative impact of 41% on annual energy consumption when combined. The investment payback period for the energy-saving measures varied from 0.8 to 8.9 years, with a payback period of 3.9 years for the combined energy-saving measures. Furthermore, the net present value was positive, indicating the economic feasibility of investing in the proposed energy-saving measures. These findings provide valuable energy-saving opportunities that can be applied to improve similar buildings on the university campus.
Boiler Efficiency Analysis Using Direct and Indirect Method
Lecture notes in mechanical engineering, Aug 9, 2022
CFD Letters
Miniaturization and utilization of low-dimensional structures of recent electronic devices have w... more Miniaturization and utilization of low-dimensional structures of recent electronic devices have witnessed some new micro cooling methods which can fulfil the cooling demand for the electronic devices. Microchannel heat sink (MCHS) is one of the micro cooling method which appears as a promising method that can provide high heat transfer rate due to small hydraulic diameter. Furthermore, microchannel heat sink is easy to be fabricated compare to other micro cooling device. Due to fast development in electronic industry, hybrid microchannel heat sink with optimal design has received a great deal of attention in order to provide sustainable cooling solutions. However, most of the studies of hybrid microchannel heat sink only provided the numerical analysis without any validation of the proposed design experimentally. This is very important since it also will determine whether the proposed hybrid microchannel heat sink can be fabricated or not. Therefore, the aim of this article is to va...
Modelling and Control Analysis of Bamboo-based Gasification: Towards the Modern Renewable Energy
DOAJ (DOAJ: Directory of Open Access Journals), Dec 1, 2021
Numerical investigation of drag force on micro-sized magnetic beads in microchannel with chamber design
Biological cells or bioparticles separation is a primary step in most biological studies. One of ... more Biological cells or bioparticles separation is a primary step in most biological studies. One of the microfluidic bioparticles separation methods is the magnetic-based method. Integrated microfluidic magnetic bioparticle separation device is made up of a microfluidics channel and a magnetic system. From past studies, the design of the microfluidic channel is least discussed in comparison with the magnetic system. To fill this gap, this study has focused on numerical simulation of a microfluidic channel with chamber design and the drag forces experienced by the magnetic beads. Simulation of the microfluidics channel was done with ANSYS Fluent software. The width ratios of trapping chamber and main channel ranged from 1 to 20, the flow rates ranged from 1 μL/min to 100 μL/min, and the bead sizes ranged from 5 μm to 25 μm were used in the numerical investigation. It was discovered that as the width ratio between the trapping chamber and main channel increases, the maximum velocity decreases, causing the Reynold's number to decrease. The pressure drop become greater at higher flow rate. Higher width ratio caused the drag force to reduce at a constant microbead size. At a constant width ratio between the trapping chamber and main channel, larger microbead sizes caused larger drag force. The microfluidic system with width ratio of 20 and flow rate of 1 μL/min produced the lowest drag force, 3.64 x 10 4 pN. Since particle trapping would occur when the magnetic force is larger than the drag force, therefore a high gradient magnetic system which offered high magnetic force was proposed to be integrated with the microfluidics system
Energy efficiency in academic buildings through optimization and operational strategies
Electricity consumption in commercial buildings needs serious and particular attention due to cur... more Electricity consumption in commercial buildings needs serious and particular attention due to current situation of increased world fuel prices. This paper presents the potential savings in order to achieve energy efficiency in academic building through optimization and operational strategies. This study also helps to identify the energy savings gap within the building through energy saving measures and application of renewable technologies. There are three main components that have been selected as the subjects of investigation, i..e., the cooling equipment, lighting and electrical appliances. A number of existing analytical tools such as ASHRAE CLTD/CLF, lumen method, net present value and benefit cost ratio have been adopted during the course of conducting this research. The results showed that the usage of air-conditioning, lighting and electrical appliances can be reduced by 12%, 52% and 40%, respectively when all the energy saving measures were in place and implemented.
The high heat transfer coefficients in microchannels are attractive for direct cooling of electro... more The high heat transfer coefficients in microchannels are attractive for direct cooling of electronic systems requiring high heat-flux removal. In this work we are presenting the results of a study on self-similar heat sinks for liquid cooled electronics, made from copper, designed for industrial application and for large scale production. The internal structures, where the most part of the active cooling takes place, have been designed in order to achieve high heat transfer coefficients. As it is almost impossible to validate the design and describe the flow characteristics inside the device via analytical solutions, a well known numerical code was employed to have an insight of the thermal-fluid distributions. It is clear from the simulation that even if copper is characterized by a high thermal conductivity, most of the heat is removed in the overflow-structure, on the side of the device adjacent to the source of heat. This paper attempts to critically analyse a comprehensive list...
The study of micro cooling heat transfer from a hot surface has been performed by using a device ... more The study of micro cooling heat transfer from a hot surface has been performed by using a device consisting of short micro channels. These devices have been developed by the Institute of Micro Process Engineering at the Karlsruhe Institute of Technology. The investigation was focusing mainly on the heat transfer and pressure drop problem for a single-phase flow device. The objective of this study is to achieve a compromise value of heat flux and pressure for short microchannel heat sink. An experimental rig has been developed, and a microchannel heat sink with microchannel dimensions of 800 μm width, 200 μm length and 100 μm height was tested to investigate the characteristics of the device. A simulation work has been performed using a simplified model from the actual device and was then validated with the experimental result. Further improvement has been carried out on the model and simulated to predict the most compromising value between heat fluxes, pressure drop and substrate te...
Thermal hydraulic performance of microchannel device is affected mainly by its geometrical parame... more Thermal hydraulic performance of microchannel device is affected mainly by its geometrical parameter. The purpose of this study is to investigate the effect of multilayer microchannel arrangement to the thermal hydraulic performance of microchannel arrays. Numerical analysis was conducted to simulate three different microchannel arrangements by varying mass flow rate and heat flux imposed on the microchannel device. The simulation model is a simplified version which consists of eight microchannels in a single row and contains four layers for model one while model two has an arrangement of eight-seven-eight-seven microchannels in four layers and model three has an arrangement of seven-eight-seven-eight microchannels in four layers. The boundary condition that was set for heat flux ranged between 200 W/𝑐𝑚 2 to 1000 W/𝑐𝑚 2 while mass flow rate that flow into the device was varied between 20 kg/h to 80 kg/h. From the simulation result, it is shown that certain arrangement of microchannel in multilayer channels contribute to the enhancement of heat transfer and at the same time reducing the pressure drop of the system.
Solar and biomass potential of renewable energy in selected ASEAN countries and Japan
Journal of Physics: Conference Series, 2021
ASEAN region is believed to have a great potential for biomass and solar energy generation due to... more ASEAN region is believed to have a great potential for biomass and solar energy generation due to its abundance of sunlight, rain, and fertile land. However, these resources are still underutilized as the current rate of renewable energy is relatively low, whereby most countries are still highly emphasizing fossil fuels. The use of fuel without replenishing the fuel source will ultimately deplete the resource in very much the same as fossil fuels currently utilized. While the concept of fuel replenishment seemed simple, the implementation posed a challenge to meet. This is where free energy in the form of solar, wind, wave, underground thermal, and biomass is being harnessed. Therefore, these forms of energy also have certain limitations depending on the geographical and the availability of the sources throughout the region. This study aims to analyze the current potential renewable energy scenario and future prospect of renewable energy resource for biomass and solar energy in sele...
CFD Letters, 2020
Rapid development in the electronic industry witnesses many tremendous advanced technologies whic... more Rapid development in the electronic industry witnesses many tremendous advanced technologies which work with high power density. As a result, an advanced cooling technique, namely, microchannel heat sink (MCHS) is required to fulfil the current cooling demand due to unpredicted increment of power density in a high-density microchip. A microchannel heat sink performance can be enhanced by improving the working fluid properties and or improving the design of cooling passage that contributes to the augmentation of heat transfer rate. In this paper, the optimization of hydrothermal performance was conducted by studying the effect of triangular cavity pitch location (Cavity 1, CV1: 60 µm; Cavity 2, CV2: 100 µm; Cavity 3, CV3: 140 µm) on fluid flow and heat transfer characteristic in the hybrid microchannel heat sink (Triangular cavity with rectangular rib microchannel heat sink, TC-RR MCHS). The result revealed that the TC-RR MCHS with the triangular cavity pitch location of 140 µm (CV3) showed superior performance over other pitch locations (CV1 and CV2) for all the Reynolds number (Re number). The optimum Performance Factor, PF , achieved by CV3 pitch location was 1.76 at Re number of 350. It indicates that the proposed design with CV3 is suitable for the technology that requires less pumping power consumption.
International Journal of Heat and Mass Transfer, 2017
A three-dimensional numerical simulation was conducted to study the characteristics of fluid flow... more A three-dimensional numerical simulation was conducted to study the characteristics of fluid flow and heat transfer in new design of microchannel heat sink with sinusoidal cavities and rectangular ribs (MC-SCRR) for Reynolds number ranging from 100 to 800. A comparative analysis has conducted to the performance of the proposed design with related geometries such as microchannel with rectangular ribs MC-RR and microchannel with sinusoidal cavities MC-SC. The results showed that thermal performance of MC-SCRR is superior over both MC-RR and MC-SC. The new design of MC-SCRR has proved the ability to combine between two important features; large flow area which significantly reduces the pressure drop and high flow disturbances which caused by existence of ribs in the central portion of channel. The overall performance of MC-SCRR is evaluated in term of friction factor, Nusselt number and performance factor. The effect of three geometrical parameters; relative cavity amplitude (k) relative rib width (b) and relative rib length (C) on the convective heat transfer and pressure drop have been investigated. The performance factor Pf for MC-SCRR with k = 0.15, b = 0.13 and C = 0.5 achieves 1.85 at Re = 800.
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Papers by NATRAH BINTI KAMARUZAMAN FKM