Abstract: In this paper the effect of spoilers on aerodynamic characteristics of an airfoil were observed by CFD.As the experimental airfoil NACA 2415 was choosen and spoiler was extended from five different positions based on the chord length C. Airfoil section is designed with a spoiler extended at an angle of 7 degree with the horizontal.The spoiler extends to 0.15C.The geometry of 2-D airfoil without spoiler and with spoiler was designed in GAMBIT.The numerical simulation was performed by ANSYS Fluent to observe the effect of spoiler position on the aerodynamic characteristics of this particular airfoil. The results obtained from the computational process were plotted on graph and the conceptual assumptions were verified as the lift is reduced and the drag is increased that obeys the basic function of a spoiler.

Abstract: This article deals with the study of antiwear and antifriction properties of bitter rapeseed oil and sesame oil and their blends containing numerous amounts of benzoic acid at variable temperatures. The experimental results indicate that bitter rapeseed oil exhibits good antiwear and antifriction properties as compared to sesame oil under the same experimental conditions. The addition of benzoic acid enhances the antiwear and antifriction properties of both oils.

Abstract: The present work studies the hydrodynamics of a swirling fluidized bed (SFB) for packed and swirling regimes using an analytical model that draws inspiration from the order-of-magnitude analysis approach. In minimizing the complexity in solving the hydrodynamics model in SFB, the multiple-dimensional modeling in a cylindrical coordinate (r,?,z), which requires a complex partial differential equation solution, is reduced to one-dimensional formulation in only the axial direction (z). The model is based on the principles of force and moment equilibrium when the fluid passing through the bed particles. It is used for predicting the axial variation of hydrodynamic properties such as angular velocity of bed particles, linear velocity of bed particles and gas velocity across the bed. Hydrodynamics of SFB are related as a function of angle of injection, mass of bed, superficial velocity of fluid and the density of particle and fluid gas. Pressure drop across the bed height is further estimated using hydrodynamics of SFB. Experiment is carried out in a swirling fluidized bed with two different sizes of spherical PVC particles. The model shows good agreement between the theoretical and experimentally obtained bed pressure drop.

Abstract: In this study we analyzed the amount of gas emissions, that bring cars into the atmosphere, according to their production years, in accordance with the requirements established manufacturing factories. Results show that pollution level from vehicles produced after 2000, is about 3 times smaller than those produced before 1995. The amount of polluting gases caused by vehicles is performed in an urban junction for current structure of vehicles in circulation and for the proposed structure with produced vehicles after 2000. Results show that it can achieve a reduction of pollution at the junction up to 2.8 times. At the end is treated and the impact of technical maintenance of vehicles in increasing of the environmental pollution level. The results show that in the current situation, 60% of vehicles exceed allowed pollution limits up to 3 times, and even vehicles produced after 2000. For the reduction of pollution we have proposed the installing of magnetic devices in used vehicles, from which we obtain a reduction of the pollution level at the junction up to 1.6 times. For limitation of produced vehicles before 1999 can be achieved by placing an additional customs tax and additional tax for vehicles, that exceed pollution limits in circulation. Also it need to establish, that degree of pollution in technical control become the stopper criterion for the circulation of the vehicle. These provisions will force users to better maintain vehicles or derive from circulation them.

Abstract: Inclusion of disturbances in the control system structure of XY table during simulation process is crucial in order to closely replicate the real system in the simulation structure. An example of the distinguished disturbances during cutting operation is cutting forces. It can affect the accuracy of actual position of x and y-axis movement during the cutting operation. Thus, it is important for control designer to include the cutting force disturbance before designing the controller for the XY table system. This paper is focused on the fundamental aspect on how to extract the useful cutting forces data from the raw cutting force data by showing the step by step procedure on how to implement the process. In addition, method on how to convert from the selected cutting forces disturbance data into the form of voltage so that the disturbances is possible to be injected into the system is also being touched and finally, the discussion on the relationship between machine spindle speed and the cutting force generated is also being addressed comprehensively.

Abstract: Disturbance forces acting on a system can greatly influence both positioning and tracking accuracy. This is especially important in machining process such as milling process. This paper is focused on the compensation of cutting forces in a XY high speed milling table using a sliding mode control (SMC). The performance of the sliding mode controller is then compared with a classical PID controller as a mean of comparing its effectiveness. Actual cutting forces for different depth of cuts and spindle speeds are applied in the numerical analysis. These are collected from several milling experiments using a Kistler dynamometer and analyzed further using Fast Fourier Transformation (FFT) for spectral analysis purposes. The PID controller is designed based on open loop and closed loops criteria. Chattering phenomenon on the sliding mode control is addressed by substituting the signum function with a sigmoid-like function. The numerical analysis showed that the robust sliding mode controller is able to compensate for different disturbance forces while suppressing chattering effect.

Abstract: Esterification and transesterification reacting vessels are the core unit operations of typical industrial biodiesel production plants. Feedstock with a high free fatty acid is esterified first in an acid condition before continuing to the transesterification under presence of an alkaline catalyst. Process analysis is an important tool to a plant engineer in the biodiesel plant operation to estimate the conversion of the palm oil to biodiesel and the yield. This paper describes the process analysis for the methanolysis of crude palm oil through the esterification and the subsequent two-step transesterification in the biodiesel production plant with a capacity of 1000 kg per batch. Physical pretreatment of the crude palm oil (CPO) is necessary to remove the unsaponifiable and other undesired trace components to become bleached palm oil (BPO). Conversion at 85% (w/w) of free fatty acid (FFA) to biodiesel has been achieved in the esterification of BPO with methanol under acid catalyst reaction. The first transesterification is able to produce up to 88% (w/w) conversion of triglycerides (TG) to biodiesel. The remaining TG is carried out in the second step of the transesterification to complete the reaction toward achieving a high methyl ester content. Analytical method using gas chromatography is used for validation against the theoretical results. GC analysis results conforms the conversion estimated by the process analyses based on the material balance, especially in the esterification and first-step transesterification, 81% and 88%, respectively. After one hour retention time of the second-step transesterification, 95% conversion of TG to biodiesel has been achieved. The process analysis applied at the equilibrium states shows consequently in accordance with the GC analysis results. Therefore, it offers a useful compendium to a plant engineer for better understanding of the biodiesel processes.

Abstract: For network access, it is always desired that a fibre optic network connectivity be the major area of cost minimization, while keeping quality of service as high as possible. This is because overall cost of setting up a fibre optic cable route is usually very high in relation to other components of the network. In this study, three buildings clusters were mapped to the University Network Operating Center, and the network was developed as a fail-safe network, so that in the case of damage to a cable or connecting component, users are not cut out. The problem was formulated as a Mathematical Programming problem and solved the resulting transportation problem using MATLAB linear programming solution. Results from the mathematical model shows an optimized cost for which a fibre Optic network connectivity can be further developed.

Abstract: Arterial disease of the upper extremity is an uncommon occurance, most commonly caused by atherosclerosis.In some patients with arterial disease, surgical bypass by vein grafting or vein interposition may be performed. However, due to the length kink between the existing artery and applied vein graft or more of the length of the applied vein graft may get blocked or severely narrowed. The objective of this study is to investigate the influence of blood flow on a failed vein graft due to length kink. The 3-D computational fluid dynamic method was employed to determine pulsatile flow velocity, pulsatile pressure gradient, and wall shear stress impact on the mismatched diameter of artery-vein graft model. We expect that pulsatile flow velocity, pulsatile pressure gradient and wall shear stress impact on mismatched diameter of artery-vein graft model to behave non-hydraulically compared to an ideal length model.