NUMERICAL SIMULATIONS OF FLOW BEHAVIOR IN DRIVEN CAVITY AT HIGH REYNOLDS NUMBERS

In recent years, due to rapidly increasing computational power, computational methods have become the essential tools to conduct researches in various engineering fields.  In parallel to the development of ultra high speed digital computers, computational fluid dynamics (CFD) has become the new third approach apart from theory and experiment in the philosophical study and development of fluid dynamics.  Lattice Boltzmann method (LBM) is an alternative method to conventional CFD.  LBM is relatively new approach that uses simple microscopic models to simulate complicated microscopic behavior of transport phenomena.  In this paper, fluid flow behaviors of steady incompressible flow inside lid driven square cavity are studied.  Numerical calculations are conducted for different Reynolds numbers by using Lattice Boltzmann scheme.  The objective of the paper is to demonstrate the capability of this lattice Boltzmann scheme for engineering applications particularly in fluid transport phenomena.   Keywords-component; lattice Boltzmann method, lid driven cavity, computational fluid dynamics

Effects Of Equivalence Ratio On Performance And Emissions Of Diesel Engine With Hydrogen And Water Injection System At Variable Injection Timing

This paper aims to develop a comprehensive development and research for performance and emissions of diesel engine fuelled with hydrogen and water at variable injection timing. Experiments have been conducted to compare the performance and emissions between diesel alone, diesel with hydrogen and hydrogen-diesel and water injection pressure. addition of hydrogen into diesel engine resulted in higher pressure which lead to huge indicated work. Furthermore, injecting water into diesel engine with hydrogen mixture indicated a desirable outcome. Existence of water in combustion slightly decreased the amount of emissions but opposite in term of performance. The fact is water injection exist in combustion will absorb a portion of heat release which will result low in combustion process thus lead to low in performance production otherwise production of NOx emission is low. In conclusion, humidification in combustion engine is a great idea toward a high performance and low in emissions production compared to diesel alone operation which leads to a green technology production

PID Controller for Vibration Reduction and Performance Improvement of Handheld Tools

This paper proposes a PID Controller to mprove handheld tools performance and at the same time reduce vibration occurs during its operation. Two experiments has been setup to record vibration of handheld drill using accelerometer placed at certain points of the hand drill. Through experiment, the obtained data was analyzed using Fast Fourier Transform (FFT) and Operational deflection shape (ODS) technique and the data being verify which gives the natural frequency at 476.07Hz which is 5.7% higher that theoretical value. From the data the PID controller is designed and tunes using Ziegler Nichols method which gives peak amplitude at 0.0144 and settling time at 0.45s. From the result it is believed that this proposed controller can reduce the vibration and give good improvement to the handheld tool performance

Finite Element Analysis on Brake Disc of an Educational All-Terrain-Vehicle

All-terrain vehicle is famously used for various purposes such as in civilian and military.The use of finite element analysis in a preliminary design stage has been demonstrated to be cost and time effective. In this paper, the finite element analysis of a brake disc for All-Terrain-Vehicle (ATV) is demonstrated. Eulerian-Lagrangian method was employed in this work where simple annular ring was used as the disc model. This study is limited to thermal and contact analysis between the disc and brake pad. The results in term of temperature and stresses distribution is obtained and presented. Moreover, the lateral displacement of the disc due to the friction contact is also shown. These results are then used to as a technical guideline in designing brake system for a fully customized ATV

Design of Chassis Frame for All-Terrain Vehicle for Educational Purposes

All-terrain vehicle is famously used for various purposes. The design of the chassis of this vehicle is critical in determining the overall strength. In this paper, the design chassis frame for the use of all-terrain vehicle (ATV) is presented. In designing the chassis frame, a proper design method was employed. Finite Element Analysis (FEA) was utilized to determine the maximum stress and displacement of the frame when a particular load is applied onto it. Structure modifications need to be done if the chassis frame could not sustain the applied load. After the design process is completed, the fabrication of the frame is conducted by students of the engineering faculty. The fabricated frame will be used as the main part for a project of which a complete ATV will be developed. The main purpose of the project is to instill the interest among the student in engineering through the application of classroom

Optimization Of Flame Stabilization Limits In Meso-Scale Tube Combustors With Wire Mesh

In the last two decades, with the continued depletion of energy resources and the need for better power sources for small scale devices, researchers have become increasingly interested in meso and micro-scale combustion. Flame stability of a meso-scale combustor depends on a few important factors such as combustor wall thickness, wall thermal conductivity and inner diameter. In order to enhance the combustor performance such as the operational limits, it is vital to fundamentally understand these determinant factors. In this research, simulations and experiments were performed to investigate the factors affecting the flame stabilization in meso- scale tube combustors with stainless steel wire mesh. The inner diameter of the meso-scale cylindrical tube combustors is fixed to 3.5 mm while the wall thickness is maintained at 0.7 mm. The wire mesh is located between the unburned and burned gas region of the combustor. The numerical simulations were performed using a three-dimensional (3-D) numerical model, from which the results in terms of gas and wire mesh temperature contours, blowout limits, combustor outer wall temperature distribution and combustion efficiency were established. In the experiments, the equivalence ratio and mixture flow velocity were varied and the effects in terms of flame stabilization limits were recorded. The main objective of utilizing a 3-D numerical model is to successfully demonstrate the role of thermal path from the tube combustor wall to the wire mesh in enhancing the flame stabilization near the blowout limits. The numerical results show that the direction of the thermal path plays a significant role in improving the blowout limits. It is also demonstrated that more heat can be recirculated to the unburned gas region with the use material with higher wall thermal conductivity in burned gas region. As a result, the flame stabilization limits can be enhanced

Flame-Spread Behavior Of Biodiesel (B20) In A Microgravity Environment

Indonesia has implemented a policy of using diesel fuel containing 20 percent biofuel (commonly known as B20 biodiesel), as stated in Energy and Mineral Resources Ministerial Decree No. 23/2013. This study investigated the flame-spread characteristics of biodiesel (B20) in a microgravity environment through drop tower facilities. This is due to the difficulty in creating droplet sizes similar to the real liquid sprays in the combustion chamber of diesel engines. The experiment used biodiesel (B20) droplets with a diameter 1 mm. The results show that the biodiesel (B20) droplets have characteristics of a flame–spread limit distance SBC/dC0limit = 7. This paper discusses the characteristics of biodiesel (B20) droplets in detail

THERMAL ANALYSIS OF A OF BRAKE DISC ROTOR FOR PERSONAL ELECTRIC VEHICLE

In this paper, thermal analysis of a brake disc rotor design for a personal electric vehicle(PEV) is demonstrated. The finite element method was used to obtain the temperature behavior during braking and non-braking conditions. Steady state response in temperature distributions was conducted for this research paper. The analysis is limited to heating and cooling condition of the designed brake disc rotor

Numerical Simulations of Shear Driven Square and Triangular Cavity by Using Lattice Boltzmann Scheme

In this paper, fluid flow patterns of steady incompressible flow inside shear driven cavity are studied. The numerical simulations are conducted by using lattice Boltzmann method (LBM) for different Reynolds numbers. In order to simulate the flow, derivation of macroscopic hydrodynamics equations from the continuous Boltzmann equation need to be performed. Then,the numerical results of shear-driven flow inside square and triangular cavity are compared with results found in literature review. Present study found that flow patterns are affected by the geometry of the cavity and the Reynolds numbers used