Arbitrary Lagrangian-Eulerian form of flowfield dependent variation (ALE-FDV) method for moving boundary problems

Flowfield Dependent Variation (FDV) method is a mixed explicit-implicit numerical scheme that was originally developed to solve complex flow problems through the use of so-called implicitness parameters. These parameters determine the implicitness of FDV method by evaluating local gradients of physical flow parameters, hence vary across the computational domain. The method has been used successfully in solving wide range of flow problems. However it has only been applied to problems where the objects or obstacles are static relative to the flow. Since FDV method has been proved to be able to solve many complex flow problems, there is a need to extend FDV method into the application of moving boundary problems where an object experiences motion and deformation in the flow. With the main objective to develop a robust numerical scheme that is applicable for wide range of flow problems involving moving boundaries, in this study, FDV method was combined with a body interpolation technique called Arbitrary Lagrangian-Eulerian (ALE) method. The ALE method is a technique that combines Lagrangian and Eulerian descriptions of a continuum in one numerical scheme, which then enables a computational mesh to follow the moving structures in an arbitrary movement while the fluid is still seen in a Eulerian manner. The new scheme, which is named as ALE-FDV method, is formulated using finite volume method in order to give flexibility in dealing with complicated geometries and freedom of choice of either structured or unstructured mesh. The method is found to be conditionally stable because its stability is dependent on the FDV parameters. The formulation yields a sparse matrix that can be solved by using any iterative algorithm. Several benchmark stationary and moving body problems in one, two and three-dimensional inviscid and viscous flows have been selected to validate the method. Good agreement with available experimental and numerical results from the published literature has been obtained. This shows that the ALE-FDV has great potential for solving a wide range of complex flow problems involving moving bodies

Arbitrary Lagrangian-Eulerian form of flowfield dependent variation (ALE-ADV) method for moving boundary problems

Flowfield Dependent Variation (FDV) method is a mixed explicit-implicit numerical scheme that was originally developed to solve complex flow problems through the use of so-called implicitness parameters. These parameters determine the implicitness of FDV method by evaluating local gradients of physical flow parameters, hence vary across the computational domain. The method has been used successfully in solving wide range of flow problems. However it has only been applied to problems where the objects or obstacles are static relative to the flow. Since FDV method has been proved to be able to solve many complex flow problems, there is a need to extend FDV method into the application of moving boundary problems where an object experiences motion and deformation in the flow. With the main objective to develop a robust numerical scheme that is applicable for wide range of flow problems involving moving boundaries, in this study, FDV method was combined with a body interpolation technique called Arbitrary Lagrangian-Eulerian (ALE) method. The ALE method is a technique that combines Lagrangian and Eulerian descriptions of a continuum in one numerical scheme, which then enables a computational mesh to follow the moving structures in an arbitrary movement while the fluid is still seen in a Eulerian manner. The new scheme, which is named as ALE-FDV method, is formulated using finite volume method in order to give flexibility in dealing with complicated geometries and freedom of choice of either structured or unstructured mesh. The method is found to be conditionally stable because its stability is dependent on the FDV parameters. The formulation yields a sparse matrix that can be solved by using any iterative algorithm. Several benchmark stationary and moving body problems in one, two and three-dimensional inviscid and viscous flows have been selected to validate the method. Good agreement with available experimental and numerical results from the published literature has been obtained. This shows that the ALE-FDV has great potential for solving a wide range of complex flow problems involving moving bodies

The effects of biochar application method on soil properties and plant growth performance / Muhamad Fadhli Mohd Asri

The glasshouse study was conducted to determine the effect of biochar application method on soil properties and plant growth by using biochar derived from empty fruit bunch (EFB). There was four treatments of application method incorporated biochar and soil such as treatment (T1) control soil only, treatment (T2) biochar in side soil, treatment (T3) biochar in broadcast soil and Treatment (T4) incorporated or mixture biochar and soil. The main objective is evaluated the effect of biochar application on soil properties and plant growth performance. The result showed that incorporated biochar and soil was the best method application biochar. Treatment incorporated biochar and soil has significant effect on the plant height, chlorophyll content and soil properties as compared to other treatments

A Study on Social Network Blogs as Political Tool on Information Technology Students' Perspective

The developments of newest communication technology, especially web based applications such as weblogs, have changed the media landscape. In countries with controlled media system, the emergence of weblogs provides an option medium to those who want to disseminate views generally suppressed by the mainstream media. Issues deemed sensitive by the local media seldom get due coverage. Even if there is coverage, it is presented from the viewpoint that is consistent with the views and philosophy of the elite and the government. Departing on the premise that blogging offers a relatively wider public sphere than the print media; discourses on political issues on different forms. Hence, this paper examines and discusses the perception, acceptance and belief of UUM IT student through political blog

Numerical study of the flow over symmetrical airfoils with ground effects

The paper presents the ground effects on the flow over five NACA symmetrical airfoils by analyzing the coefficients of lift. The unbounded flow over a selected airfoil was first simulated, and the results were validated against the established data in order to validate the method used in obtaining the lift coefficients. In the presence of ground, we kept the angle of attack to be constantly zero throughout the computations. Ground clearances were set based on those for aircrafts whose wing cross sections are the airfoils of interest. ANSYS was used for such numerical computations. We illustrate percentage increment of lift that is inversely proportional to the ground clearance. This work sheds insight on the important parameters that need to be taken into account in the operational of an aircraft

Poket Musafir: a guide for smart muslim travelers

Prayer (solat) is one of the five pillars of the Islamic faith and it has been stated in the hadeeth of Jaabir (may Allah be pleased with him) who said; I heard the Messenger of Allah (peace and blessings of Allah be upon him) say; “Between a man and shirik and kufr there stands his giving up prayer”. In other words, it is prayer that distinguished the believer from the disbeliever. Given the importance for Muslims to perform their five daily prayers even during travel, an android application, Poket Musafir was developed to guide them in performing their obligations. Poket Musafir included in its menu details on rulings regarding Jamak and Qasr (combining and shortening of prayers) during travel, calculation on distance to see whether one is eligible to perform Jamak and Qasr prayers, common Q&A faced by Muslim travellers in performing their prayers. This application also has quizzes, and can be used by school students to help them understand the topic and test their knowledge, on what they have learnt in a more dynamic way instead of static text in the textbook. Poket Musafir was developed using Android Studio, Adobe Photoshop CS6, GNU Image Manipulation Program (GIMP) and Adobe Illustrator

Flowfield-dependent variant method for moving-boundary problems

A novel numerical scheme using the combination of flowfield-dependent variation method and arbitrary Lagrangian–Eulerian method is developed. This method is a mixed explicit–implicit numerical scheme, and its implicitness is dependent on the physical properties of the flowfield. The scheme is discretized using the finite-volume method to give flexibility in dealing with complicated geometries. The formulation itself yields a sparse matrix, which can be solved by using any iterative algorithm. Several benchmark problems in two-dimensional inviscid and viscous flow have been selected to validate the method. Good agreement with available experimental and numerical data in the literature has been obtained, thus showing its promising application in complex fluid–structure interaction problems

A Study on Aerodynamics and Stability Characteristics of a Bell-Shaped Span-Load Wing

The existence of the new bell-shaped span-load wing is said to has the best lift distribution especially comparing to the elliptical wing. Bell-shaped span-load wing is designed by configuring the twist of the wing. However, the information on the aerodynamic and stability characteristics of the bell-shaped span-load wing is limited. Thus, the main purpose of the research is to evaluate the aerodynamic and stability characteristic to strengthen the claim of the capability of bell-shaped span-load wing in producing minimum induced drag. As the research is expected to be beneficial to the aviation design team, detailed information regarding the lift distribution as well as the induced drag produced is analysed at the optimum angle of attack and the results is further explained in this research. The numerical method for the analysis is done by using Lifting Line Theory (LLT) in the XFLR5 software which can analyse the wings of aircraft in terms of its aerodynamic and stability characteristic. Then, the comparison of the aerodynamic characteristics for bell-shaped span-load, elliptical span-load and tapered wing done in this research is to strengthen the appeal made stating that the bell-shaped span-load wing is the best type of wing ever existed and may replace the elliptical wing as the best wing shape with aerodynamically most efficient. The research has proven that along the wingspan, the bell-shaped span-load wing produced the lowest and minimum induced drag when being compared. At the optimum angle of attack of bell-shaped span-load wing, though the lift produced is slightly lower than the elliptical and tapered wing, the difference in the induced drag is obvious as bell-shaped span-load wing produces induced drag that is lower than 0. In other words, starting from the semi span of the wing to the wingtip, the bell-shaped span-load wing managed to be the most aerodynamically efficient wing

The effects of air supply and nitrogen sources on Scenedesmus Quadricauda

Microalgae have been investigated for the production of different biofuels and the feedstock are gaining interest in the present day due to their fast growth potential added with relatively high lipid, carbohydrate and nutrients contents. The purpose of this project is to perform a research to grow the commercial microalgae and to produce significant amount of lipid content from microalgae harvested as a viable alternative renewable energy. The commercial microalga chosen is Scenedesmus Quadricauda. The project also intended to study on the effects of air flowrate and nitrogen limitation on cell growth and lipid production. The microalga was cultivated in Afnor Medium with working volume of 5L in cylindrical photobioreactors. The temperature and pH value were in range of 22-25oC and 7-8 respectively for each photobioreactor. The first part of this project was conducted using different flowrates of air supply of range 1.0 to 6.0 L/min. The results show that, as the flowrate of air supply increased from 1.0 to 4.0 L/min, the biomass collected was also increased. However, as the flowrate of air supply was further increased to 5.0 and 6.0 L/min, the biomass collected was decreased. The second part of this project was conducted by controlling the total amount of nitrogen supply to the culture medium in decreasing range of 100% to 20% of nitrogen. The results show that the lipid yield was increased with decreasing amount of nitrogen whereas the biomass obtained was decreased. Besides, the lipid content based on the dry mass percentage was also increased with decreasing amount of nitrogen supplied