Comparison Study between FEM Simulation and Experimental of Heat and Mass Transfer in Kek Lapis Sarawak Baking

Kek Lapis Sarawak is specialty dish from Sarawak. Kek Lapis Sarawak industry contributes a lot to the state’s economy. In cake industry, the use of oven in the baking process contributes to high energy consumption. Nowadays, energy has become an operational issue and there is a need to minimize energy consumption to reduce production cost. This research aims to optimize the baking process for an efficient energy consumption. Therefore, it is important to investigate the relationship between baking temperature, time and cake quality. Accurate temperature and time will define an efficient baking process. Kek Lapis Sarawak baking process has been modelled and simulated using finite element method (FEM). Results from the model was validated with an experiment. There is specific oven temperature needed to enable perfect gelatinization and coagulation to happen which is 190 °C. While baking time are varied by layers. The baking time is reducing as more layers added.  The finding shows interdependent relationship between porosity, thermal conductivity and moisture content where higher porosity  can lead to poor thermal conductivity

Pressure stresses generated due to supersonic steam jet induced hydrodynamic instabilities

The phenomenon that involves direct contact of steam with water is called Direct Contact Condensation (DCC). This phenomenon has been observed/prevailed in most of the power and process industries. The phenomenon of direct contact condensation involves heat, mass and momentum transfer across the highly fluctuating interface between steam jet and surrounding water giving this process an intricate nature to be studied. More recently the observation of hydrodynamic instabilities at the interface between supersonic steam jet and water has given a new facet to the study of DCC. In the current study the equivalent von-Mises Stress, equivalent elastic strain and total deformation in the Perspex vessel that has been incurred due to the pressure stresses has been studied. These pressure stresses have been generated due to the condensing supersonic steam jet induced hydrodynamic instabilities. It has been investigated first by experimentally observing the temperature fluctuations in axial and radial directions across supersonic steam jet which actually depicts these instabilities. Then Direct Contact Condensation (DCC) model has been used to conduct the CFD study using a commercial code Ansys®. Accompanied with this a mock up study has been done in which the pressure loads computed using DCC model have been coupled to the Perspex vessel structure using one way Fluid Structure Interaction (FSI) analysis in Ansys® to compute the true scale equivalent von-Mises Stress, equivalent elastic strain and total deformation generated by hydrodynamic instabilities induced pressure stresses. On true scale, hundreds of Pico scale deformation has been computed in the Perspex vessel confinement

Feasibility of Non-thermal Plasma Assisted Semiconductor Material Synthesis for Thermoelectric, Photovoltaic and Energy Applications

Silicon being the major component in the semiconductor industry has proved itself very effective in myriad applications that include its use in transistors, energy storage, photovoltaics etc. A boom into its efficiency has emerged with the use of the Nano technology, when the same material is used at Nano scale for the fabrication of the devices in the said applications, it provides promising characteristics. Yet the synthesis techniques for the usage of the silicon as material at Nano scale encounter myriad hurdles, however, still the application of non-thermal plasma at Nano scale has found promising results in this field. It could bring about a huge improvement into its efficiency and can thus become ideal for the vast industrial uses. Yet it encounters several issues that makes this practice economically not feasible, like it needs more time to process such material rather than the conventional methods to synthesize materials on the liquid, solid or gas phases have their own short comings which will result into certain compromises the synthesizers have to deal with based on the properties of the end finished product. On the contras, Non-thermal plasma processing is found cost effective with properties like lack of agglomeration and more efficiency

Development of wind tunnel for ultrafine palm oil fuel ash separator

Palm Oil Fuel Ash (POFA) is a pozzolanic material that has great potential in concrete production. POFA sizes range from 1 to 10 μm is preferable. Thus, there is a need for efficient method to separate the POFA according to the sizes needed. This study explores the idea of using a simple wind tunnel as a separator for ultrafine POFA. The existing operation of the wind tunnel is simulated using ANSYS-CFX, a numerical modelling software. The identified weakness of the wind tunnel design is located at the hopper. The wind tunnel is simulated with a different air inlet velocity in order to visualize the air flow profile as well as air flow energy at the hopper. Different air inlet velocities has a similar air flow profile but the air flow intensity is different. For further study the modifications of the air flow profile were conducted. By altering the hopper angle shows that the air flow profile is changed. Based on the simulation results, the hopper at 60° yields the best flow characteristic. At angle 60° of the hopper, the air flow is mostly directed downward into the tunnel and the air flow energy is low. Therefore, it allows the POFA to be directed into the tunnel and reduced the ultrafine POFA losses at the tip of the hopper. This practical method utilizes a simple open wind tunnel that enables the process to be more efficient and cost efficient thus the production of ultrafine POFA can be increased

Micro-Needle with Polygonal Structure of Micro-Channel for Stress and Blood or Drug Flow Optimization

This paper presents micro-needle with different tip and inner structure of the needle for optimizations of pain stresses and drug or blood deliveries. The micro-needle comes with several design's parameters of length ranging from 5 mm to 50 mm and diameter ranging from 100 µm to 200 µm. A hollow micro-needle with four different tip designs which are 10°, D3-2, D6 and Quadruple are also designed to optimize the pain stresses parameters. In order to improve the flow deliveries, the inner structure of the channel is modified into various polygonal shape which is square, hexagon and dodecagon. It shows that, having less contact surface area between the skin and micro-needle's tip and polygonal shape of inner channel has better performance for both of the objectives. These feasible region of average velocity and stress of the micro-needle have satisfied in determining the best design for tip and inner channel of the micro-needle under certain conditions and constraints. The three-dimensional geometry study had improved the insertions performance and efficiencies in painless drug or blood deliveries

Development of a prototype model for fully automated Sarawak layered cake machine

Layered cake also known as kek lapis is very synonym to Sarawak and very famous souvenir to tourist who travels to Sarawak. The exclusive savour and colourful layered design attribute has secure its constant demand all the year especially during festive seasons. The products are not only catered for Sarawak but also exported to Peninsular Malaysia, Singapore and Brunei. The industry contributes almost RM 3 million a year to the entrepreneurs. However, the tedious traditional process is unable to cope with the demand. Manual process is highly dependent on labours and the labours skills has direct influence on the quality of cakes produced. The development follows systematic engineering design process. Concept of sectional base mechanism has been chosen for the machine. The automatic machine has includes all basic processes namely filling of mixture to the baking tray, baking, layered, pressing and cooling. The proposed model is expected to produce 216 moulds per day, which is 430% improvement from the current production rate (50 moulds). Estimated manufacturing cost is about RM 37,000 only. Copyright © 2014 BICET –All right reserved

Heat transfer and computational simulations on the drying process of a kiln

In this paper, the analytical and computational results are presented for a large-scale ceramic-tiles drying kiln. A lumped-parameter model was initially derived for the drying process of the kiln. This has led to the development of mathematical models for the energy conservation and convective heat and mass transfer drying process. Diffusion on the boundary layers of the tiles was also derived based on the basis of moisture isotherm, drying curve and different temperature profiles. This also takes into consideration the internal moisture transportation. The developed partial differential equations were discretized using the central-difference approximation method, which were further verified by a computational fluid-dynamics solver and the Gauss-Siedel iterative method. The modelling and simulations performed on the partial differential equations give possible auxiliary energy conservation and improvement on the drying process of the kiln

Assessment of Tidal Energy Resources from Tidal Streams in Sarawak Coastline

Tidal energy is one of the most predictable and reliable source of renewable energy. The kinetic energy from tidal streams can be used for generation of electrical power. The purpose of this paper is to assess the extractable tidal energy resources from tidal streams in Sarawak coastline. In order to achieve the objectives, the tidal stream speed and corresponding power densities were computed through empirical equations. The investigation of potential locations was made by weighting of different elements required for the selection of suitable sites. It was found from the analysis that only a single site of Pulau Triso at Batang Lupar fulfilled the minimum required tidal stream speed and the clearance of shallow-draft oceangoing vessels. Off Kuala Igan met only the clearance requirements and the tidal stream speed were lower than set limits. Other examined sites could not fulfil any criterion set for the site selection. It was concluded that Pulau Triso is the only feasible site for the extraction of tidal stream energy among examined locations in Sarawak. However, only shallow-draft oceangoing vessels could pass through the proposed site if the turbines are installed for power generation. Keywords: Tidal streams, Tidal power, Tidal turbines, Ocean energy