Papers by Keyword: CFD

Abstract: In the present investigation, the distribution features of particulate matter in residential environment is researched. Using computational fluid dynamics technique, we have considered lots of different conditions such as wind speed, direction and diameter of particulate. It can be concluded that both the wind speed and direction have a significant influence on the spreading process of the particulate. And lots of experimental data are given to reflect the influence by different conditions, also the detailed analysis be.

Abstract: In this paper, we used orthogonal experiment method and Computational Fluid Dynamics (CFD) technology to simulate the thermal environment of the iron and steel workshop. By comparing and analyzing the temperature distribution and air flow of workshops with different window structures, we obtained an optimization of natural ventilation design for industrial workshop. The research results can be used for the structure design or reformation of industrial workshops as reference.

Abstract: Construction dust may lead to Silicosis, a disabling respiratory disease which severely threatens the life of construction workers. Therefore, it is important to predict and determine the safety area of dust generated by the construction process and the corresponding protective measures that must be adopted. In this paper, based on real site data, we modelled and simulated the pneumatic drill holes in rock drilling processes to analyze the dust distribution on construction sites. Our simulation results show that the dangerous distance from the pneumatic drill hole is 3.5m. Within the dangerous distance, the dust concentration ranged from 0.039 mg/m³to30mg/m³, and decreased as distance increases. Within the dangerous distance, dust alleviation technologies are strongly recommended and appropriate protective measures must be adopted by construction workers.

Abstract: This research aims at presenting the airflow simulation within the high speed Hard Disk Drive by installing the device called Spoiler which helps to reduce the airflow velocity before colliding with the read/write head. Due to the high speed airflow within the hard disk drive, it directly impacts on the vibration of the read/write arm and consequently causing the damage and inaccuracy function of the read/write head. The rotational speed of the platter is specified at 20,000 rpm (round per minute). According to this study, the length of Spoiler is divided into 4 values which are 15, 20, 25 and 30 millimeters respectively. Thereafter, apply each length of the Spoiler to the commercial software called Computational Fluid Dynamic (CFD) by using K-epsilon model. The result shows that the length of Spoiler at 30 millimeters can reduce the average airflow velocity by 57.18%.

Abstract: Tesla disc turbine has many advantages compared with the traditional blade turbine, but there are few researches on fault diagnosis of Tesla disc turbines for industrial dust blower. In this paper, 3-dimensional model Tesla turbine is established by using CFD software FLUENT to analyze the inner flow field in the given pressure and boundary conditions. The experiments provide a good foundation for the theoretical research and the application of fault diagnosis of the Tesla disc turbines for industrial dust blower.

Abstract: A coaxial gas mixer is designed for mixing air and synthesis gas or syngas as fuel. Three-dimensional computational models are harnessed to analyze and predict the influence of the mechanical tabs aspect ratio and number on the mixing characteristics and performance of the gas mixer. Attention is concentrated on the influence of mechanical tabs on the air-fuel ratio, pressure loss and mixing quality. The optimum design of the mechanical tab was realized with aspect ratio of 0.32 and 4 tabs with 45^o tab angle. The coaxial gas mixer using the optimized mechanical tabs was realized with λ of 1.13 corresponding to pressure loss of 37.2 Pa at 100 m³/h air-flow rates and the coefficient of variation (CoV) of mixing was 0.29. The gas mixer with the mechanical tabs had much better mixing performance than the gas mixer without mechanical tabs with only relatively small increase in pressure loss.

Abstract: Hydropower is one of the most widely source to produce electricity for domestic houses as well as for industries around the world. However, for those off-grid settlements the pico-hydro scheme is more suitable due to its cost-effectiveness (less maintenance), clean, user-friendly and do not involved with huge construction works. Even the installation of this type of hydropower scheme is very simple as do it yourself (DIY) concept. One of the most popular pico-hydro turbines which have been implemented widely in rural areas until nowadays is propeller type or also known as axial turbine. Propeller turbine is selected because it is suitable to operate under low head with high flow rate condition. However, in this particular case, low head with low flow rate of water are the two main parameters which need to be considered. This is because during dry or drought season the water level of the rivers will become low and fluctuated, and this scenario affected the performance of the propeller turbine itself. In order to overcome this problem, the runner blades of the propeller turbine need to be redesigned to suit with this nature behavior. Therefore, in this study the runner blades with flat profile with few different angles and number of blades will be applied under 2 meters head. On the other hand, since the low flow is another parameter which needs to be focused therefore the value of the water flow rate has been set to 13 l/s. Analysis tools such as Computer Fluid Dynamic (CFD) is applied in this study in order to determine the most optimum results based from few selected parameters which has been mentioned. From the CFD’s final result, 3 blades with angle 30⁰ was the best combination among the parameters involved.

Abstract: The resistance and the hydrodynamic characteristics of the Sprint Master canoe that is used in Universiti Teknologi Malaysia (UTM) have been studied at different speeds using Computational Fluid Dynamics (CFD) method. The resistance of the canoe at different speeds has been measured in UTM marine technology center (MTC). The finite volume code Ansys CFX has been used for carrying out the numerical simulations for the hull form of the canoe at the same experimental speeds. The Volume of Fluid method (VOF) has been used with Ansys CFX for capturing the free surface flow around the canoe hull at the same experimental speeds. The Shear Stress Transport (SST) turbulence model has been used in the RANSE code. The grid generator ICEM CFD has been used for building the grids for the RANSE code solver. The numerical results compare very well with the experimental results at the different speeds.

Abstract: Airflow and heat transfer simulation was conducted for a double-skin façade (DSF) system equipped with shading devices in the cavity, using computational fluid dynamics (CFD) with RNG turbulence model and PISO algorithm, for five conditions of slat angles (θ=0°, 30°, 45°, 60°, 90°). The present study indicates that the presence of shading devices influences the temperatures, the ventilation rate and the air distribution in the DSF system. Besides, the different angles will make different influences.

Abstract: Concept of the water mist spray in CKV system is to clean the gas filter at kitchen hood. This research aims to analyze the behavior and flow characteristics of water mist spray produced by spray nozzle. A computational fluid dynamics (CFD) model with k-epsilon turbulence method is a simulation tool for the characterization of sprays. The fluid flow for case1, case 2 and case 3 have the same pattern type of graph. Changes have seen in fluid flow pressure and velocity. The value of fluid flow pressure was decreasing from the first point at water inlet until to the last point at nozzle orifice. The total pressure values for case 1, case 2, and case 3 are 99.997 kPa, 199.991 kPa and 299.992 kPa respectively. The highest velocity is recorded at the liquid tip of the nozzle which is about 144.15 m/s for case 3. In the other hand, the highest value of fluid flow pressure was recorded at the water inlet part.