Buletin Fakulti Kejuruteraan Mekanikal dan Pembuatan Edisi 1/2021

SarjanaSainsKejuruteraanTenagaLestari(MDL)merupakanprogrampascasiswazahterbaharuFakultiKejuruteraanMekanikaldanPembuatan(FKMP)dibangunkanuntukmemenuhikeperluantenagapakardalambidangtenaga,terutamanyaberkaitankecekapantenaga,tenagabolehdiperbaharuidanpengurusantenaga.PrograminitelahmendapatsokongandankerjasamadaripadapihakKementerianTenagadanSumberAsli(KeTSA)danSuruhanjayaTenaga(ST),dimanasebagainilaitambah,graduanbagiprogramyangmengikutipengkhususanPengurusandanKecekapanTenagalayakdiiktirafsebagaiPengurusTenagaElektrikBerdaftar(REEM)

Moisture absorption and diffusivity of epoxy filled layered-structure nanocomposite

This paper studies moisture absorption and diffusivity of epoxy reinforced layered structure nanocomposites and its effect on fracture toughness. Two different types of layered fillers employed in the study were clay and graphene platelets, in which both surface layers were unmodified and modified by characterized by swelling analysis and fracture toughness measurement. The outcomes surfactant. The nanocomposites were showed that the moisture absorption and diffusivity decreased with the addition of layered fillers. It was found that the modified graphene platelets and clay outperformed the unmodified layers and neat epoxy in terms of reduction of moisture absorption and diffusivity. The modified graphene platelets reduced the moisture uptake and diffusivity about 30% and 33%, respectively compare to neat epoxy, thus indicates its outstanding performance in barrier applications. However, once the nanocomposites were swelling in the water for 5 days, it is noticed that the fracture toughness of nanocomposites were reduced significantly about 35% in average. Nevertheless, the modified graphene platelets still display the better performance compare to the other samples although there was reduction of fracture toughness

Incompressible flow simulation using S.I.M.P.L.E method on parallel computer

Komputer selari merupakan gabungan beberapa pemproses yang bertujuan meningkatkan keupayaan se~ebt,iah sistem komputer dalam melaksanakafi sesuatu pengatucaraan. Dalam projek ini, sistem komputer seiad yang digu[)akan dikenali selJagaf sistem komputer serari berkelompok. Kelebihan menggunakan sistem ,komputer selari berkelo,mpok ini ialah ia mampu bergerak-sendiri sebagai komputer sesiri jika tidak beropera~i sebagai komputer s~laci. Peri sian komputer selari yang boleh digunakan sebagai sistem operasi kepada sistem komputer selari berkeIompok ini termasuklah uNIX, Window NT atau Linux. Projek ini rnemberikan penumpuan dalam penggumian sistem kotnputer seIari berkelompok rnenggunakan perisian PVM untuk rnenyelesaikan persamaan Navier-Stoke dalam membuat simulasi dua dimensi aliran tidak boleh mampa~ dalam ruang segiempat. Kaedah yang digunakan adalah berasaskan algorfuna SIMPLE dan algoritrna SIMPLE yang {elah diubahsuai dengan men,.ggunakan kaedah pel'tIbahagian domain dan kaedah pembahagian fungsi. Ketepatan kedua-dua kaedah tersebut telah dibandiflgkan dengan keputusan piawai yang berkaitan dengan rnasalah aliran dua dimensi dalam ruang segiempat. Keupayaan kedua-dua kaedah tersebut dari segi rnasa perlaksanaan, kecepatan dan keberkesanan juga telalLJ!iperoIehi dan didapati penggunaan komputer selari telah rnemberikan prestasi yang Iebih baik dalam menyelesaikan masalah persamaan Navier-Stoke tersebut. Dengan kaedah pembahagian domain, didapati masa perla1>.Sanaan daPJIt £il)urangkan sebanyak 700/6-' rnanakala dengan menggunakan kaedah pembah~gf~ri fungsi, masa perlaksanaan dapat dikurangkan sebanyak 25 % berbartding dengan menggunakan komputer sesiri

Study of vibration absorbers using epoxy reinforced natural fibers

It is well known fact that vibrations contribute to excessive wear, fatigue failure and other premature failure of machine components. Thus, various methods have been applied to control these vibrations. One of the commonly used is vibration absorber. The aim of this paper is to explore the potential of epoxy reinforced natural fibers as an alternative material for vibration absorber. Both mechanical properties and dynamic characteristic of the composites are investigated through tensile test and transmissibility test, respectively. Two types of natural fibers were selected for the study; coconut coir and pineapple leaf. The results show that the tensile modulus of composites increases with the increase of fiber content, although the strength was found decreases. This reduction indicates an ineffective stress transfer between the fiber and matrix. From the tensile test result, 20 vol% of pineapple leaf fiber was found to be the optimum fraction, in which afterward was employed for fabrication vibration absorber. Meanwhile, from the transmissibility test, it was noticed that when base excitation increases, the resonance peak and attenuation frequency were changed to the lower value. The fixed-fixed end beam with attached composite vibration absorbers showed that the resonance amplitude of the beam decreased significantly. More absorbers attached on the beam produce better result in attenuating the global structural vibration

Incompressible Flow Simulation Using SIMPLE Method on Parallel Computer

This paper is concerned with the development of a parallel algorithm on cluster of workstation with Parallel Virtual Machine (PVM) for solving the finite difference Navier-Stokes and energy equations. The numerical procedure is based on SIMPLE (Semi Implicit Method for Pressure Link Equations) developed by Spalding. The governing equations are transformed into finite difference forms using the control volume approach. The hybrid scheme which is a combination of the central difference and up wind scheme was used in obtaining a profile assumption for parameter variations between the grids points. The Domain Decomposition Method (DDM) was used to decompose the domain into a small domain and each of the domains was solved by different processors. The accuracy of the parallelization method was done by comparing with a benchmark solution of a standardized problem related to the two dimensional buoyancy flow in a square enclosure. The results are shown in the forms of contour maps of non-dimensional temperature and velocities

From clay to graphene for polymer nanocomposites-a survey

The development of aerospace and automotive in- dustries requests lightweight, high-performance materials, and polymer nanocomposites are ideal candidates in this case, which is shown by the increasingly more publications in this research field over the past two decades. However, the perfor- mance of nanocomposite not only depend on the properties of their individual constituents, but on their morphology and surface characteristics of fillers as well. Selections of nanofillers geometries, e.g. particulate, fibrous or layered have a tremendous influence on the properties of nanocomposites and their processing methods. In this paper, we review the chronological works performed in the field of polymer nano- composites, in particular epoxy nanocomposites reinforced with layered fillers, such as clay and graphene. Surprisingly layered fillers are commercially available and more cost- effective than nanoparticles and carbon nanofibres, and these make them to the most extensively studied fillers that can be geared toward future applications, particularly in large-scale polymer nanocomposite production

Evolution engine technology in exhaust gas recirculation for heavy-duty diesel engine

In this present year, engineers have been researching and inventing to get the optimum of less emission in every vehicle for a better environmental friendly. Diesel engines are known reusing of the exhaust gas in order to reduce the exhaust emissions such as NOx that contribute high factors in the pollution. In this paper, we have conducted a study that EGR instalment in the vehicle can be good as it helps to prevent highly amount of toxic gas formation, which NOx level can be lowered. But applying the EGR it can lead to more cooling and more space which will affect in terms of the costing. Throughout the research, fuelling in the engine affects the EGR producing less emission. Other than that, it contributes to the less of performance efficiency when vehicle load is less

Thin film flow of non-newtonian third grade fluid down an inclined plane by variation of parameter method

In this study, a non-Newtonian third-grade fluid flow down an inclined parallel plate held horizontally against each other are investigated. As the nonlinear differential equation which governs the flow model can be obtained by using the conversation of laws, the Variation of Parameters Method (VPM) is then applied to solve the aforementioned differential equation. The proposed VPM is applied without any discretization, perturbation, transformation or restrictive assumptions and is free from round off errors and calculation. Analytical solution solved by Runge-Kutta numerical solution and the VPM show excellent agreement. Effects of flow parameters β and m on the velocity field are demonstrated graphically with comprehensive discussions. Numerical results reveal the complete reliability of the proposed VPM

From clay to graphene for polymer nanocomposites-a survey

The development of aerospace and automotive in- dustries requests lightweight, high-performance materials, and polymer nanocomposites are ideal candidates in this case, which is shown by the increasingly more publications in this research field over the past two decades. However, the perfor- mance of nanocomposite not only depend on the properties of their individual constituents, but on their morphology and surface characteristics of fillers as well. Selections of nanofillers geometries, e.g. particulate, fibrous or layered have a tremendous influence on the properties of nanocomposites and their processing methods. In this paper, we review the chronological works performed in the field of polymer nano- composites, in particular epoxy nanocomposites reinforced with layered fillers, such as clay and graphene. Surprisingly layered fillers are commercially available and more cost- effective than nanoparticles and carbon nanofibres, and these make them to the most extensively studied fillers that can be geared toward future applications, particularly in large-scale polymer nanocomposite production