Sofian Mohd

An Evaluation of Drag Coefficient of Wind Turbine System Installed on Moving Car

This study presents a simulation result of an evaluation of the aerodynamic performance of a moving car with a wind turbine system. Sedan type cars (approaching the size of Proton Wira car) were modeled using the SolidWork software and simulation was done by ANSYS FLUENT software. Three car models with different wind turbine system positions (in front of the front bumper, on top of the hood and on top of the roof) plus one model without the wind turbine system were simulated. The study proved that the position of the wind turbine system installation will change the characteristic of the air flow around the car body and affects the aerodynamic performance of the car. Extended front bumper of a car is not significantly affecting the aerodynamic performance of the car. This extended bumper seems to be the suitable area to install a wind turbine system and the investigation shows that the aerodynamic performance of the car improved due to lower drag coefficient, Cd..

CFD Simulation of Aerial Crop Spraying

Aerial crop spraying, also known as crop dusting, is made for aerial application of pesticides or fertilizer. An agricultural aircraft which is converted from an aircraft has been built to combine with the aerial crop spraying for the purpose. In recent years, many studies on the aerial crop spraying were conducted because aerial application is the most economical, large and rapid treatment for the crops. The main objective of this research is to study the airflow of aerial crop spraying system using Computational Fluid Dynamics. This paper is focus on the effect of aircraft speed and nozzle orientation on the distribution of spray droplet at a certain height. Successful and accurate of CFD simulation will improve the quality of spray during the real situation and reduce the spray drift. The spray characteristics and efficiency are determined from the calculated results of CFD. Turbulence Model (k-ɛ Model) is used for the airflow in the fluid domain to achieve a more accurate simulation. Furthermore, spray simulation is done by setting the Flat-fan Atomizer Model of Discrete Phase Model (DPM) at the nozzle exit. The interaction of spray from each flat-fan atomizer can also be observed from the simulation. The evaluation of this study is validation and grid dependency study using field data from industry.

Flow Simulation of Modified Duct System Wind Turbines Installed on Vehicle

This study investigates the characteristics of airflow with a flow guide installed and output power generated by wind turbine system being installed on a pickup truck. The wind turbine models were modelled by using SolidWorks 2015 software. In order to investigate the characteristic of air flow inside the wind turbine system, a computer simulation (by using ANSYS Fluent software) is used. There were few models being designed and simulated, one without the rotor installed and another two with rotor installed in the wind turbine system. Three velocities being used for the simulation which are 16.7 m/s (60 km/h), 25 m/s (90 km/h) and 33.33 m/s (120 km/h). The study proved that the flow guide did give an impact to the output power produced by the wind turbine system. The predicted result from this study is the velocity of the air inside the ducting system of the present model is better that reference model. Besides, the flow guide implemented in the ducting system gives a big impact on the characteristics of the air flow.

Ground proximity effect on the flow over NACA 4412 multi-element airfoil in clean configuration

The paper presents the influence of ground distance on aerodynamic characteristics of the flow over NACA 4412 multi-element airfoil in clean configuration. The angle of deflection was kept constant throughout the computations. Finite volume method was used for the grid generation and the numerical calculation. Further investigation suggests the best range of angle of attack where the aerodynamic performance of the airfoil increases in the presence of ground. Furthermore, the condition of flow separation jeopardizing the airfoil performance appeared. It was found that at certain range of angle of attack, the cushion of high pressure at the pressure side of the airfoil is insufficient to compensate the influence of the separation. This work shed insight on the important parameters that need to be taken into account in the operational of an airplane.

Small Horizontal Axis Wind Turbine under High Speed Operation: Study of Power Evaluation

Mechanical energy is produced through the rotation of wind turbine blades by air that convert the mechanical energy into electrical energy. Wind turbines are usually designed to be use for particular applications and design characteristics may vary depending on the area of use. The variety of applications is reflected on the size of turbines and their infrastructures, however, performance enhancement of wind turbine may start by analyzing the small horizontal axis wind turbine (SHAWT) under high wind speed operation. This paper analyzes the implementations of SHAWT turbines and investigates their performance in both simulation and real life. Depending on the real structure of the rotor geometry and aerodynamic test, the power performance of the SHAWT was simulated using ANSYS-FLUENT software at different wind speed up to 33.33 m/s (120km/h) in order to numerically investigate the actual turbine operation. Dynamic mesh and user define function (UDF) was used for revolving the rotor turbine via wind. Simulation results were further validated by experimental data and hence good matching was yielded. And for reducing the energy producing cost, car alternator was formed to be used as a small horizontal wind turbine. As a result, alternator-based turbine system was found to be a low-cost solution for exploitation of wind energy.

Computational fluid dynamic (CFD) analysis on ALUDRA SR-10 UAV with parachute recovery system

In an operation, belly landing is mostly applied as recovery method especially on research Unmanned Aerial Vehicle (UAV) such as Aludra SR-10. This type of landing method may encounter tough landing on hard soil and gravel which create high impact load on the aircraft. The impact may cause structural or system damage which costly to be repaired. Nowadays, Parachute Recovery System (PRS) recently used in numerous different tasks such as landing purpose to replace belly landing technique. Parachute use in this system to slow down flying or falling UAV to a safe landing by opening the canopy to increase aerodynamic drag. This paper was described the Computational Fluid Dynamic (CFD) analysis on ALUDRA SR-10 model with two different conditions i.e. the UAV equipped with and without parachute in order to identify the changes of aerodynamic characteristics. This simulation studies using solid models of aircraft and hemisphere parachute and was carried out by using ANSYS 16.0 Fluent under steady and turbulent flow and was modelled using the k-epsilon (k-e) turbulence model. This simulation was limited to determine the drag force and drag coefficient. The obtained result showed that implementation of parachute increase 0.25 drag coefficient of the aircraft that is from 0.93 to 1.18. Subsequent to the reduction of descent rate caused by the parachute, the drag force of the aircraft increase by 0.76N. These increasing of drag force of the aircraft will produce lower terminal velocity which is expected to reduce the impact force on the aircraft during landing.

Flame spread behavior over combustible thick solid of paper, bagasse and mixed paper/bagasse

Flame spread behavior on combustible solid is one of important research related to Fire Safety Engineering. Now, there are a lot of combustible solid composed from mixed materials. In this study, experiments have been conducted to investigate flame spread behavior over combustible solid composed by paper, bagasse and mixed paper/bagasse. Experimental data is captured by using video recording and examined flame spread shape and rate. From the results obtained, shows that the different materials produce different flame spread shape and rate. Different flame shape is seen between all types of samples. Flame spread rate of 100% paper is faster than the one of 100% bagasse. Based on the result, it is also inferred that the material composition can be influenced on the flame spread shape and flame spread rate of mixed paper/bagasse.

Comparative analysis on flow over cylinder between commercial code and open source algorithm

The understanding of flow over cylinder is crucial especially in aerodynamic study. The present of vortices due to flow separation at the stagnation point of cylinder is differing with the changes of Reynolds number. This study aims to investigate the flow characteristics over cylinder with different Reynolds numbers. Computational modelling is used in predicting the flow characteristic of flow over cylinder. Two different softwares has been used: Code::Blocks as compiler and commercial code as a basis of comparison. Three different Reynolds number imposed in this study are 20, 40 and 100 to compare the accuracy and speed of convergence. Validation has been made with the previous finding to benchmark the accuracy of the result. The parameters used in this study are velocity in x and y direction, Mach numbers, drag coefficient and pressure coefficient. A brief comparison between sequential and optimized configuration which includes multiple processors is also considered. Results show that the drag coeffici...

A survey on the use of ram air turbine in aircraft

Ram Air Turbine (RAT) is used as an emergency power source to feed vital apparatuses required for aircrafts in case of main systems failure. The purpose of this paper is to explain the function of RAT as a wind harvesting technology for aircraft and its advantages as auxiliary power generator during landing process. This survey allows a more axiomatic understanding on the use of different RAT approaches in aircraft construction. The survey in this paper also provides a sight to simultaneously use RAT for emergency case and power harvesting as future energy.

Assessment of wind energy potential in the capital city of Chad, N’Djamena

In this study, statistical analysis of a long term meteorological data of 10 years have been presented to reveal the potential of wind power as a source of energy generation in the capital of Chad, N’Djamena. The recent ten-year period wind data were collected from the Hassan Djamous International Airport at N’Djamena. The wind characteristics and wind energy potential were analyzed using Weibull distribution function. The results show that the values of the shape parameter k, and scale parameter c, varied over a wide range. The annual highest values of the Weibull shape parameter k, and scale parameter c, were 1.59 and 4.12 m/s respectively. It was also found that higher wind speeds occurred during dry season, i.e. November to July and the lower wind speeds occurred during the wet season, i.e. August to October. The annual average of the most probable wind speed and wind speed carrying maximum energy were respectively 1.86 m/s and 6.48 m/s. Likewise, the wind power density was ranging between 55.96 W/m2 ...