11 research outputs found
Aerodynamic Analysis of Propeller for Heavy Lifting Drone Applications Using Blade Element Momentum Analysis
Nowadays, drone technology is seen to be rapidly advancing in various fields and applications including photography, military, transportation, sports, and many more. Therefore, each drone model may require different aerodynamic requirements, thereby requiring different types of propeller designs. By revolving and generating airflow, the propellers give drones or unmanned aerial vehicles (UAV) a lift force. This research examines the airflow characteristic and calculates the thrust force value for propellers. This investigation compares the thrust coefficient trend grafts produced by four propellers with various rotation speeds and parameters using the extended blade element momentum theory. This program is developed to perform the calculation of thrust and torque for a given propeller blade geometry. Five different types of propellers are analysed and simulated using an in-house MATLAB program. The effects of rotational speeds are then added to these databases. At low advance ratios compared to a generic blade element-momentum model, a considerable improvement in modelling accuracy is seen when results are compared to experimental ones. The calculation may overestimate performance by 5% to 10%
Comparison of 2D and 3D modelling applied to single phase flow of nanofluid through corrugated channels
Nanofluid flow through non-corrugated and corrugated channels is studied using a
two-dimensional (2D) and three dimensions (3D) numerical simplification. Due to the
high computational costs of a full 3D grid model, the 2D approach offer a more practical
advantage. However, little information about its validity is available. The aim of this
study is to explore to which extent 2D simulations can describe the flow within a 3D
geometry, and to investigate how effective the commonly used 2D numerical
simplification is in nanofluid flow through non-corrugated and corrugated channels. A
case study has implemented with 2D and 3D mesh models to compare their results
taking into consideration the analysis of heat transfer and pressure drop. A simulation
has been carried out using Ansys fluent software to compare the results for different
Reynolds Numbers ranges from 10000 to 30000 and different geometries non�corrugated, semicircle and rectangular channels. The results show that for non�corrugated channel there is a slight difference between 2D and 3D results for all
Reynolds number ranges, while for both semicircle and rectangular corrugated
channels, the difference becomes larger for high Reynold’s Number
Numerical Study of Three-Dimensional Models of Single- and Two-Phase Nanofluid Flow through Corrugated Channels
This study delves into computational fluid dynamics (CFDs) predictions for SiO2–water nanofluids, meticulously examining both single-phase and two-phase models. Employing the finite volume approach, we tackled the three-dimensional partial differential equations governing the turbulent mixed convection flow in a horizontally corrugated channel with uniform heat flux. The study encompasses two nanoparticle volume concentrations and five Reynolds numbers (10,000, 15,000, 20,000, 25,000, and 30,000) to unravel these intricate dynamics. Despite previous research on the mixed convection of nanofluids using both single-phase and two-phase models, our work stands out as the inaugural systematic comparison of their predictions for turbulent mixed convection flow through this corrugated channel, considering the influences of temperature-dependent properties and hydrodynamic characteristics. The results reveal distinct variations in thermal fields between the two-phase and single-phase models, with negligible differences in hydrodynamic fields. Notably, the forecasts generated by three two-phase models—Volume of Fluid (VOF), Eulerian Mixture Model (EMM), and Eulerian Eulerian Model (EEM)—demonstrate remarkable similarity in the average Nusselt number, which are 24% higher than the single-phase model (SPM). For low nanoparticle volume fractions, the average Nusselt number predicted by the two-phase models closely aligns with that of the single-phase model. However, as the volume fraction increases, differences emerge, especially at higher Reynolds numbers. In other words, as the volume fraction of the nanoparticles increases, the nanofluid flow becomes a multi-phase problem, as depicted by the findings of this study.</p
Fuel consumption mathematical models for road vehicle – a review
Since the invention of the automobile, engineers and researchers alike have worked towards improving the automobile in various ways from safety, handling and performance to efficiency and durability. As technology in the IT and computing sector evolves into a very helpful tool for detailed calculations, an advantage and possibility for detailed models is there to assist with very detailed assessment on fuel and energy consumption on today’s vehicles. This review is meant to explore in detail what has been achieved by years of joint research through advanced modelling and the following factors such as emissions software and how these models play an important role in sustainable road transport for the masses. The mathematical models also display varying characteristics where models are created striking a balance between complexity, accuracy, and the number of variables to be included
Establishment of method for identification of water quality in fire-tube boiler - a case study for UTHM Biodiesel Plant's Boiler
Water treatment process for a boiler is essential to ensure the boiler operates at an optimum condition. Accordingly, the present study aimed to introduce a water quality assurance method for a boiler at UTHM biodiesel plant. The water quality is investigated by experimental study, which includes the monitoring of total dissolved solids, potential of Hydrogen (pH), sulphate, iron and chloride content, total hardness, and alkalinity. The water sampling was conducted at three different points. Subsequently, for the purpose of water quality assurance, the amount and type of chemical needed for a boiler to maintain a substantial value of water treatment were also been determined. The results obtained in this study has revealed that most of the parameters investigated are within the allowable limits. Further work needs to be done to establish whether the steam produced by the boiler can be influenced by the boiler water quality
Fuzzy Model Reference Adaptive Controller for Position Control of a DC Linear Actuator Motor in a Robotic Vehicle Driver
This paper presents the controller development for DC linear actuator motors that are used to control the throttle and brake pedals of a passenger car with automatic transmission. The Fuzzy Model Reference Adaptive Control (Fuzzy MRAC) system allows the vehicle to follow speed vs. time profiles of driving cycles by dynamically adjusting the position of the driver pedals in a vehicle. The designed controller is implemented to a virtual vehicle model to determine the required position of the linear pedal actuators over a standard driving cycle. The driving-cycle simulation is conducted using Matlab Simulink and the performance of the controller is analyzed based on overshoot, rise time, settling time and mean square error whereas the robustness test was carried out via set-point tracking method. The result shows 19.7988 s rise time, 0.1619% overshoot, 32.6532 s settling time and 0.0041 mean square error. The results have proven Fuzzy MRAC to be a viable option for use in highly dynamic systems such as automotive standard driving cycle controllers
Impacts of corrugation profiles on the flow and heat transfer characteristics in trapezoidal corrugated channel using nanofluids
In this paper, turbulent forced convection of nanofluids flow in different configurations of trapezoidal corrugated channels is numerically investigated over Reynolds number ranges of 10000–30000. This study evaluates the effects of four different types of nanofluids which are Al2O3, CuO, SiO2 and ZnO–water under constant heat flux condition (10kw/m2). The governing equations of continuity, momentum and energy are solved using finite volume method (FVM). The study was carried out at 8% volume fraction of nanoparticles with 20nm particle diameters. Simulation results show that the corrugation profile has a significant impact on the thermal performance compare with straight profile. Furthermore, by adopting new channel geometry, the heat transfer enhancement can be improved more than two times that for straight channels. Among the nanofluid evaluated here, SiO2-water offers the highest enhancement of heat transfer. For all studied forms, the nozzle rib configuration of trapezoidal corrugated channel achieved maximum PEC and can lead to more compact heat exchangers
Efforts to establish Malaysian urban drive-cycle for fuel economy analysis
Emissions from motor vehicles are known to be the major contributor of air pollution. Pollutants that are commonly concerned and regulated for petrol engines are Hydrocarbons, Carbon Monoxide, Nitrogen Oxides and Particulate Matter. One of the most important factor that vary these pollutants is the engine operating condition such as cold start, low engine loads and high engine loads which are found during actual driving. In actual driving conditions, particularly in urban areas, vehicles regularly travel at idle, low or medium speeds which signify the engine part load operations. Thus urban driving carries a crucial weight on the overall vehicle fuel economy. Understanding the implications of urban driving conditions on fuel economy will allow for trategic application of key technologies such as cylinder deactivation in the efforts towards better efficiency. This paper presents the measurement and analysis of engine condition during Malaysian actual urban driving in an attempt to formulate representable fuel consumption data. The measurements were conducted through multiple on-road urban driving with an instrumented 1.6 litre car. Data was collected using the “chase” technique. Driving conditions were recorded over different routes within the selected urban areas, with considerations on the level of population, density and traffic congestion. The on-road driving was performed to measure vehicle speed, engine speed, accelerator pedal traces, engine torque and fuel consumption. The fact that high traffic congestion in urban area dictates the vehicle movements and the engine running conditions were analysed by clustering the variables. The analyses show that idling and cyclic speed ranging up to 25km/h were the most frequent conditions captured in the Malaysian urban driving. Using the cluster analysis, 10 important conditions were identified in developing a framework for the Malaysian actual urban driving conditions, towards representable fuel economy analysis
Exergy analysis of organic rankine cycle and electric turbo compounding for waste heat recovery
With such tough legislation on current emission standards, car manufacturers are focusing on increasing the efficiency of their engines with the development of advance waste heat recover (WHR) technology. Organic Rankine Cycle (ORC) and Electric Turbo Compound-ing (ETC) system have a good potential to be used as exhaust energy recovery. This paper compares the exergy availability and losses between the ORC and the ETC. In this particular study, exhaust data from the Proton 1.6L CamPro CFE turbocharged engine was used. This particular engine already has a main turbocharger, making the added WHR as a secondary recovery system to further increase the engine efficiency. Both systems are coupled to a 1 kW electric generator for ease of comparisons. At first the available exergy is calcu-lated for both WHR technologies. Exergy losses from rotating the generator are analysed to finally determine the thermal efficiency of the overall system. Exergy calculation is simplified to only account for chemical and physical exergy since kinetic and potential energy are negligible in comparison. Available exergy for ORC was significantly high which went up to 12.5 kW with the exergy losses record-ed at 9.7 kW. The ETC achieved only 5 kW but had a small loss at 8x10-3 kW. Average thermal efficiency of the ORC systems was 10.7% compared to ETC which was 58.7%. It can be concluded that the complexity of the ORC system contributes to its downfall where mul-tiple components increase its exergy losses compared to the simplistic design of an ETC
Assessment of cycle averaged turbocharger maps through one dimensional and mean-line coupled codes
Downsizing the internal combustion engine has been shown to be an effective strategy towards CO2 emissions reduction, and downsized engines look set to dominate automotive powertrains for years to come. Turbocharging has been one of the key elements in the success of downsized internal combustion engine systems. The process of engine-turbocharger matching during the development stage plays a significant role towards achieving the best possible system performance, in terms of minimizing fuel consumption and pollutant emissions. In current industry practice, engine modeling in most cases does not consider the full unsteady analysis of the turbocharger turbine. Thus, turbocharged engine performance prediction is less comprehensive, particularly under transient load conditions. Commercial one-dimensional engine codes are capable of satisfactory engine performance predictions, but these typically assume the turbocharger turbine to be quasi-steady, hence the inability to fully resolve the pulsating flow performance. On the other hand, a one-dimensional gas dynamic turbine model is capable of simulating the pressure wave propagation in the model domain, thus serving as a powerful tool to analyze the unsteady performance. In addition, a mean-line model is able to compute the turbine power and efficiency through the conservation method and Euler’s Turbomachinery Equation. However, none of these modeling methods have been widely implemented into commercial one-dimensional engine codes thus far. The objective of this paper is to assess the possibility of numerically producing the steady equivalent cycle averaged turbocharger turbine maps, which could be used in commercial engine codes for performance prediction. The cycle-averaged maps are obtained using a comprehensive turbocharged engine model including accurate pulsating exhaust flow performance prediction. The model is validated against experimental results and effects of flow frequency on the maps are discussed in detail