Journal of Advanced Research in Fluid Mechanics and Thermal Sciences

Long-Term Solar Power Generation Forecasting at Eastern West Large Scale Solar (LSS) Farm using Random Forest Regression (RFR) Method

Muhammad Aiqal Iskandar — 2024-06-15

Precise forecasting of power generation and demand is essential for effective resource allocation and energy trading in contemporary energy systems. Power forecasting accuracy has increased dramatically since Random Forest Regression (RFR) techniques were used. The study's primary objective is to forecast electricity generation in Malaysia's Eastern West region, with a concentration on solar energy. The research process entails gathering and examining pertinent factors, weather information, and historical power data. To evaluate the accuracy and predictive potential of RFR models, a specific power grid is used for training, validation, and testing. One of the anticipated results is the creation of an accurate model for power generation predictions, which will help to optimise energy operations and smoothly incorporate renewable sources. The paper examines the advantages, disadvantages, and best practices related to RFR-based power forecasting. The dataset, which spans the years 2019 to 2023, includes 30-minute interval records for the following variables: average output power, ambient temperature, PV module temperature, global horizontal irradiance, and wind speed. Using the RandomForestRegressor class from the scikit-learn library, the RFR model is implemented. In order to assess the model's overall fit, average deviation, and sensitivity to outliers, measures such as root mean square error (RMSE), mean square error (MSE), and mean absolute error (MAE) are used on the test set. The temperature, irradiance, and AC power output of PV modules are found to be strongly correlated.

The Impact of Temperature on the Production of High Calorific Value Syngas using Cogasification Technology

Imron Rosyadi — 2024-06-15

Cogasification represents a thermochemical reaction employed to transform by combining biomass or fossil carbonaceous materials into combustible matters. Widely acknowledged as the most appealing approach among various combustible material to useful energy. This method offers significant potential for environmentally friendly energy production, boasting low carbon emissions. This study conducted gasification tests utilizing an updraft gasifier, incorporating parameters variable at 650°C to 850°C. The materials utilized consisted of a blend of Municipal-Solid-Waste (MSW) and coconut shells, maintaining a steam to biomass at 1.3. Optimum temperature at 750°C, the syngas revealed 41.30% mol CO, 20.90 mol% CO₂ 37.25 mol% H₂, and 0.55 mol% CH₄. Notably. The highest H₂ gas production was achieved at this temperature. Furthermore, the net caloric value at this temperature, surpassed other variations, reaching 374.67 kJ/mol, accompanied by the generation of 11.38% of tar and 21.1% char.

Interfacial Instabilities During Interphase Mass Transfer of Propionic Acid

Fettar Leila — 2024-06-15

We present a numerical study of the transient two-dimensional solutal Marangoni convection which occurs at the interface of a two isothermal layers’ system made of two immiscible liquids. The solute is propionic acid and is transferred through the interface from the organic phase to the aqueous phase under gravity condition. The unsteady state of this interfacial convection problem is mathematically described by the Navier-Stokes and solute mass transfer equations in both phases. The Hele Shaw approximation was incorporated in these equations and the resulting equations were solved using the COMSOL Multiphysics software. The latter is based on the finite elements’ method. The results obtained are in good agreement with the experiments and suggest that the mass transfer rate is stronger when the acid diffusion and the instability occur together.

Investigation of the Effect of Mutual Diffusion on Hydrodynamic Parameters under Fluid Displacement

Ibrahim Mammadov — 2024-06-15

Formation of stagnant zones in a reservoir is mainly determined by differences in the flow velocity of fluids in heterogeneous micro and macro porous media. Additional resistance forces to fluid flow, which are of a different nature, result in a decrease in flow velocity. Forces arising from the diffusion of fluids with different physical-chemical characteristics and acting in different directions are one such class of the above-mentioned drag forces. An increase in the degree of fluid mineralization is capable of causing changes in the flow of a continuous diffusion layer. The mathematical solution of the problems considered in the study was solved using the "Matlab" program using the Finite Difference Method. The paper presents the results of displacement studies in porous media under the assumption that the flow characteristics of displacing and displaced fluids can be controlled. Theoretical and experimental substantiations showing the effect of diffusion process in fluids on flow properties have been carried out in the displacement process. The theoretical solution and modelling of concentration change in flow of mutually soluble dispersed solutions were presented. The effect of diffusion on the flow velocity in the process of displacement of mutually soluble liquid mixtures has been evaluated.

Enhanced Thermal Comfort Prediction Model by Addressing Outliers and Data Imbalance

Hui-Hui Tan — 2024-06-15

The relationship between individuals and their thermal environment is pivotal not only for comfort but also for health and productivity. Thermal comfort, as defined by ASHRAE, reflects an individual's satisfaction with their ambient thermal conditions and can be gauged using the ASHRAE scale. In the past, traditional thermal comfort prediction models such as the Predicted Mean Vote (PMV) were used to evaluate thermal comfort. Nevertheless, the emergence of machine learning provides a more dynamic approach to predict thermal comfort of occupants. However, the subjective nature of thermal comfort introduces data ambiguities challenge which lead to the existence of outliers. Moreover, data imbalances within the dataset can cause the machine learning models to not learn the minority class effectively, resulting in the deterioration of the model. This research has developed an enhanced thermal comfort prediction model to predict the occupant’s thermal comfort by leveraging the outlier detection technique and synthetic data generator, particularly the Isolation Forest and SMOTE. The experiment showed that the proposed model is able to achieve an accuracy of 74.94%. This exhibited a slight improvement compared to the findings in prior research of using Random Forest prediction model.

The High-Performance Polymer Electrolytes Based on Agarose–Mg(ClO4)2 for Application in Electrochemical Energy Storage Devices

Nurul Izzati Ali — 2024-06-15

Electrochemical energy storage devices (EES) such as batteries and supercapacitors depend significantly on electrolytes, which have properties that significantly impact their energy capacity, rate performance, cyclability, and safety. Agarose–Mg(ClO₄)₂–based polymer electrolyte was prepared using the solution casting method by incorporating various amounts of Mg(ClO₄)₂ from 0 – 35 wt%. The presence of Mg(ClO₄)₂ as the dopant in agarose-matrix enhanced the ionic conductivity of the system from 1.796 × 10^-8 S∙cm^-1 to 6.247 × 10^-4 S∙cm⁻¹ in the composition of 30 wt% Mg(ClO₄)₂ due to the production of free ions. This system obeys the Arrhenius rule as it records the conductivity increment when temperature increases. This increment shows the amorphous nature of electrolytes, which XRD analyses by determining the crystallite size and degree of crystallinity of agarose–Mg(ClO₄)₂ polymer electrolyte. High ionic conductivity at room temperature has increased attention to this polymer electrolyte based on agarose–Mg(ClO₄)₂.

Wind Potential Assessment for Songkhla, Thailand

Chayakorn Chaitammachok — 2024-06-15

The analysis and evaluation of wind energy projects are important to understand their economic and environmental suitability for installation and operation. Using wind data from the Meteorological Department, Used WAsP software for calculating, simulating, and analyzing the Annual Energy Production (AEP) and then applied it to calculate the Levelized Cost of Electricity (LCOE) of wind turbines installed in the Songkhla province area. The selected areas are suitable for all three models of wind turbines in the simulation. From the wind data analysis, wind direct was found that in the east sector (sector 4), there is the highest wind frequency at the wind station. The simulation results from Laem son-on area and Hua khao area show suitable mean wind speeds for wind farm installations. In the wind turbine simulation, three models were compared: Bonus 300 kW MkIII, Bonus 1.3 MW, and PowerWind 56 900 kW. At the Songkhla cape area, the positions with the highest AEP were 132.485 MWh, 344.419 MWh, and 332.597 MWh, respectively. Hua Khao area, the positions with the highest AEP were 225.284 MWh, 586.303 MWh, and 540.045 MWh, respectively. In the LCOE calculations for all model of wind turbines, at both Laem Son- On and Hua Khao locations, the most cost-effective wind turbine is the Bonus 300 kW. It has an LCOE of $142.43/MWh and $83.76/MWh, respectively. Therefore, the most cost-effective location is Hua Khao.

Effects of Upper-Side Inclination Angle on Aerodynamic Loads of a Golf Cart using 3D CFD

Syamsuri — 2024-06-15

Currently, golf cars as a means of transportation vehicles have been used at large universities spread over large areas, expensive hotels and housing complexes and most recently for travel comfort, namely in the hotel industry. Theoretically, aerodynamic drag on transportation vehicles contributes around 50-60% to vehicle fuel consumption. The aim of this research is that by utilizing the upper-side inclination angle of the golf car, it can reduce aerodynamic drag and automatically reduce vehicle fuel consumption. In this paper, the effect of upper-side inclination angle on aerodynamic loads on a golf cart (i.e. total pressure, turbulence kinetic energy, velocity contour, and drag force) is investigated using 3D Computational Fluid Dynamics. The results of the research show that at the same speed, the greater the upper-side inclination angle of a golf cart the greater the drag force obtained. A tilt angle of 60⁰ with a speed of 20 km/h produces the lowest drag force value. When compared to standard (0⁰ tilt angle) the reduction in drag is around 38.06 %. In conclusion, that 3D Computational Fluid Dynamics can simulate the influence of the upper-side inclination angle on the aerodynamic load from the golf cart.

Exploring Unsteady Three-Dimensional Casson Fluid Flow through a Stretching Surface with Heat Source/Sink: A Numerical Investigation

Gobburu Sreedhar Sarma — 2024-06-15

This research aims to examine the effects of a heat source or sink and viscous dissipation on an MHD unsteady three-dimensional Casson fluid flow across a stretched sheet. Using similarity transformations, the governing partial differential equations are transformed into coupled ordinary differential equations, which are then solved numerically in Matlab. The numerical findings for several physical parameters that impact velocity and temperature profiles are described in tables and graphs. The interesting finding are recorded as follows: When the Magnetic parameter increases, the skin friction coefficient increases along x and z directions, but when the Casson parameter lowers, it decreases. The Nusselt number increases with the enhancement of viscous dissipation parameter and heat source or sink parameter. Understanding the behavior of non-Newtonian fluids in the presence of heat transfer is crucial in a number of domains, including chemical engineering, biomechanics, and material processing. These applications might benefit from this kind of study.

Natural Convection in a Spherical Porous Annulus with Diathermal Partition Wall

Sangita — 2024-06-15

The influence of the diathermal partition wall on natural convection in a fluid-saturated porous medium has been numerically studied in the present paper. A concentric diathermal wall of infinitesimal thickness is inserted in the fluid-saturated spherical porous annulus. Due to the flow symmetry along the vertical axis, only half of the sphere is considered for simulation. A Successive Accelerated Replacement Scheme has been used to solve the Darcy flow model using the finite difference method. The average Nusselt number value decreases with the presence of a partition wall within the fluid-saturated spherical porous annulus. The percentage decrease in average Nusselt number value depends upon the position of the diathermal wall within the width of the spherical annulus. There is about a 50% reduction in the average Nusselt number with a diathermal partition wall for the cases considered in this work. The results of the present investigation will help in the proper design of porous insulation in spherical porous containers for the storage of thermal energy.

Optimization of Process Parameters for Flow Nozzle with Different Geometry using Computational Fluid Dynamics Method

Vinayaka Nagarajaiah — 2024-06-15

A nozzle is a tubular structure designed to facilitate the flow of hot gases. Rocket nozzle designs typically consist of a stationary convergent section and a stationary divergent section. The term "CD" is an abbreviation for "convergent-divergent" and is used to refer to this specific nozzle type. Upgrades are being made to nozzles and other engine components in order to enhance performance and optimise thrust delivery. Application-specific improvements will be made to rocket nozzles and other current combustion expansion systems. An instance of such progress is the implementation of the bell and twin bell nozzle. This study conducted a comparative analysis of two kinds of nozzles, namely bell and conical, at different Mach speeds to ascertain which one yields the most optimal flow. Subsequently, the flow parameters were modelled with computational fluid dynamics (CFD). Ensuring optimal pressure thrust integral throughout the supersonic zone of the nozzle surface while taking the base pressure into account was the aim of the problem formulation. The research focused on irrotational flow, taking into consideration the impacts of boundary layers.

Experimental Biomass Gasification in Updraft Gasifier with Gas Outlet at Reduction Zone and Air Supply using Suction Blower

Fajri Vidian — 2024-06-15

Rice husk gasification is increasingly attractive, particularly with updraft gasifier type, because of its simple construction and ease of operation. However, updraft gasifier has a disadvantage of generating substantial amounts of tar. Tar will decompose into combustible gas when exposed to high temperatures. The reduction zone has a high temperature for tar decomposition to occur. Therefore, in this research, updraft gasifier was modified by positioning gas outlet at the reduction zone and inducing gasification air supply using a blower. Modifications are made by moving the gas outlet from the top to the middle or reduction area. The initial start-up of the system uses a blown air supply system, then after the syngas are produced by the operation, it is replaced with a sucked air supply. Two blowers are used, namely an exhalation or blowing blower for initial start and a suction blower for continuous operation. The fuel used was low bulk density, specifically rice husks. The aim was to characterize the modified gasifier, focusing on parameters such as operating time, duration of gas combustion, air-to-rice husks ratio, and flame color. Typically, the experiments were conducted under constant of air velocity and fuel quantity. The results showed that the average operating time, duration of flammable gas, and air-to-rice husks ratio were 74.25 minutes, 52.28 minutes, and 7.6 kg air/kg husk, respectively, and the flame produced was a bluish-yellow color that indicates a reduction tar.

The Effect of Viscous Dissipation and Joule Heating on Poiseuille Flow of Hyperbolic Tangent Fluid

Tamara Shihab Alshareef — 2024-06-15

In this paper, we showed the computer solutions for the Flow of Poiseuille of (MHD) hyperbolic tangent impossible-to-compress fluid Amid a pair of parallel slabs that are sloped at an angle utilizing a uniformly porous medium. Heat transfer attempts and slip boundary conditions are taken into account. In the energy equation, radiation, joule heating, and viscous dissipation are also accounted for. It is presented in a cartesian coordinate system that supplies the model of the governing equations of the hyperbolic tangent fluid flow. The equations of velocity and Temperature are solved numerically by using "ND solver built". The effects of different factors such that Hartmann number, Darcy number, slip parameter, Grashof number, Brinkman number, radiation parameter and others on velocity and temperature profiles are explored and presented in the Mathematica program. It is noticed that the profiles of velocity and Temperature are an increasing function of Darcy number, slip parameter, Grashof number, inclination angle, pressure gradient, Brinkman number, radiation parameter, and index-power parameter while they are a decreasing function of Hartmann and Weissenberg numbers. The research intends to improve our understanding of the thermal behavior of hyperbolic tangent fluids in practical applications by studying the combined effects of viscous dissipation and Joule heating on the Poiseuille flow. The potential ramifications of this phenomenon extend to multiple domains, encompassing engineering, materials science, and fluid dynamics.

Effect of Temperature on Zirconia Powder Synthesized from Amang Zirconium Oxychloride Precursor

Nur Fatinhanani Fatimah Norsham — 2024-06-15

Polymorphic zirconia is economically attractive in various applications due to its low reactivity, high strength, and stability. Zirconia can be synthesized from locally available Amang zircon sand as an inexpensive green alternative as it has a high zirconium content as reported by previous report. Unfortunately, the study was only focused on the formation of zirconium oxychloride despite of high zirconium content from the improved alkali fusion method proposed. Therefore, a further study on zirconia powder calcined in varied temperatures from Amang zirconium oxychloride precursor was done. Amang zirconia powder was then characterized in order to study the effect of temperature on Amang zirconia powder. Elemental analysis showed that zirconium composition was affected by temperature and increased as the temperature increased with the highest zirconium content of 81.28 wt.% with low impurities after calcined at 800 °C for 4 hours. The phase analysis satisfied monoclinic zirconia with minor tetragonal and cubic phase with sharper peaks as calcined temperature increased. Increased tetragonal and cubic phase was observed as the temperature was increased. Morphology analysis showed zirconia powder was angular and pyramidal with large crystal size which led to high tendency of monoclinic phase. Calcination temperature of 800 °C was determined to be the most suitable temperature to calcine high purity zirconia powder using Amang zirconium oxychloride precursor.

Experimental Analysis of a Vertical Wind Turbine using Plastic Blades

Kadhim Fadhil Nasir — 2024-06-15

It had presented for current investigation the powered performance of H vertical wind turbines for wind speed of (1, 2, 3, 4, 5, 6, 7, 8) m/s region in Al-Mussaib city-Iraq, located at 3205' North latitude and 4403' East longitude. The Experimental test rig includes H vertical wind turbine which configured and made-up in order to analyze the effect of different ambient and wind speed variable conditions on the powered performance of H typre vertical wind turbine which consists of blades which are made from plastics. The turbine blades are designed from plastic strips with a thickness of 3 mm, each part is along 50 cm in diameter, 16 cm in diameter, and the number of blades used in this experiment is six blades to form required turbine. The experiments were tested outdoor at Technical College in AL-Mussaib city-Babylon-Iraq for a period of March and April 2022. The results showed that the power output, with wind speed of minimum value 1 m/s generate 5 Watts, while with wind speed of maximum value 7 m/s generate 100 Watts. Also, the power output, with turbine rotational speed of minimum value 100 rpm generate 8 Watts, while with turbine rotational speed of maximum value 1000 rpm generate 120 Watts. Moreover, the power output, with turbine elevation of minimum value 7 m generate 100 Watts, while with turbine elevation of maximum value 21 m generate 250 Watts.