A Rudimentary Computational Assessment of Low Tip Speed Ratio Asymmetrical Wind Turbine Blades

This paper presents a computational study of novel drag type vertical axis wind turbine inspired by three design elements from nature. The aim of this study is to analyze the aerodynamic performance of the proposed design. The design is simulated in FLUENT using SST k-ω transport model via URANS turbulent model. The model is simulated in 2D in order to save computational time. The design is simulated under the influence of freestream velocity of U∞=8m/s at multiple tip speed ratios. The proposed wind turbine is composed of drag induced novel cavity vane turbine blade for energy capturing. The proposed wind turbine generated low power coefficient, Cp = 0.029 and Cp=0.025 at λ=0.2 and λ=0.3 respectively. tip speed ratio λ=0.4, λ=0.6 and λ=0.9 indicated high instability in moment generation and high negative power extraction.  Computational result indicated that the geometry of the cavity vane has impacted the performance of the turbine due to its sharp-edged corner. the proposed geometry resulted in unstable moment generation and torque deliverance which impacted the power extraction. The lack of symmetrical and streamline properties of the blades has affected one another as in terms of rotation. The cavity vane experiences high adverse pressure due to its sharp cornered geometry in returning blade which consequently impacted the rotation of the advancing blade

Novel bio-hybrid drag induced wind turbine

In the world of rapid growing economy, energy consumption by power industry and human are drastically rising which is leading to an energy crisis situation. Today several countries are investing their resources on the development of renewable energy; wind power generation. 1. Pollution Increasing carbon emission by industry and humans activities had impacted global climate which lead to increasing greenhouse gases at the atmosphere year by year regardless the campaign and regulations initiated by the government and NGO. 2. Wind turbine's design for low-wind speed Design modification were done on wind turbine by engineers in order to adapt the wind speed of the desired geographical area. Researches indicates that, drag driven wind turbines such as Savonius and Darrieus VAWTs are suitable in harvesting wind energy in low wind speed potential

Modelling and Optimization of Energy Efficient Assembly Line Balancing Using Modified Moth Flame Optimizer

Energy utilization is a global issue due to the reduction of fossil resources and also negative environmental effect. The assembly process in the manufacturing sector needs to move to a new dimension by taking into account energy utilization when designing the assembly line. Recently, researchers studied assembly line balancing (ALB) by considering energy utilization. However, the current works were limited to robotic assembly line problem. This work has proposed a model of energy efficient ALB (EE-ALB) and optimize the problem using a new modified moth flame optimizer (MMFO). The MMFO introduces the best flame concept to guide the global search direction. The proposed MMFO is tested by using 34 cases from benchmark problems. The numerical experiment results showed that the proposed MMFO, in general, is able to optimize the EE-ALB problem better compared to five comparison algorithms within reasonable computational time.  Statistical test indicated that the MMFO has a significant performance in 75% of the cases. The proposed model can be a guideline for manufacturer to set up a green assembly line in future

Novel compact fin and tube heat exchanger made of reinforced composite plate fins

Most fin and tube heat exchangers are affected by external factors over time, leading to a decrease in their efficiency. Among the most important reasons for this problem are the materials used in the manufacture of the heat exchanger. Heat exchangers are made of materials with high conductivity and are able to withstand the harsh conditions, but most of these materials are affected by corrosion such as iron, or the occurrence of electrochemical reactions that form layers with heat resistance at the surface of the material such as aluminium and copper, which negatively affects the performance of the heat exchanger. In addition, these materials have heavy weights that are difficult to use in small applications, and sometimes their prices are high for use in projects with a limited budget. To solve aforementioned problems, it possible to be a good option to use materials which have high corrosive resistance and light weight, few research work have suggested to use polymer as a material to product the heat exchanger, due to its characteristics which may limit the problems those occur in iron, copper and aluminium

Thermal conductivity and dynamic viscosity of mono and hybrid organic- and synthetic-based nanofluids: A critical review

Thermal conductivity and dynamic viscosity are two critical properties of nanofluids that indicate their heat transfer performance and flow. Nanofluids are prepared by dispersing mono or several organic or synthetic nanoparticles in selected base fluids to form mono or hybrid nanofluids. The qualitative and quantitative stability measurement of nanofluids will then be addressed, followed by a detailed discussion on how the dispersion of nanoparticles in water (W), ethylene glycol (EG), and themixture of W:EG 60:40%by volume affects the thermal conductivity and dynamic viscosity ratio. The data comparison demonstrated that the thermal conductivity ratio increases with increasing normalized concentrations, the bulk temperature of nanofluids, and the smaller nanoparticle size. The dynamic viscosity ratio is multiplied by the normalized concentration increase. Nevertheless, as the bulk temperature climbed from 0 to 80°C, the dynamic viscosity ratio was scattered, and the dynamic viscosity ratio trend dropped with increasing particle size. While the majority of nanofluids enhanced thermal conductivity ratio by 20%, adding carbon-based nanoparticles to synthetic nanofluid increased it by less than 10%. The disadvantage of nanofluids is that they multiply the dynamic viscosity ratio of all nanofluids, which increase power consumption and reduces the efficiency of any mechanical system

Modelling and optimization of energy efficient assemblyline balancing using modified moth flame optimizer

Energy utilization is a global issue due to the reduction of fossil resources and also negative environmental effect. The assembly process in the manufacturing sector needs to move to a new dimension by taking into account energy utilization when designing the assembly line. Recently, researchers studied assembly line balancing (ALB) by considering energy utilization. However, the current works were limited to robotic assembly line problem. This work has proposed a model of energy efficient ALB (EE-ALB) and optimize the problem using a new modified moth flame optimizer (MMFO). The MMFO introduces the best flame concept to guide the global search direction. The proposed MMFO is tested by using 34 cases from benchmark problems. The numerical experiment results showed that the proposed MMFO, in general, is able to optimize the EE-ALB problem better compared to five comparison algorithms within reasonable computational time. Statistical test indicated that the MMFO has a significant performance in 75% of the cases. The proposed model can be a guideline for manufacturer to set up a green assembly line in future

Development of brain tissue swelling predictive tools for ischaemic stroke patient post-treatment

Ischaemic stroke is one of the causes of death worldwide. Treatments such as thrombolysis and catheterisation must be given within 3 hours after stroke onset, in which treatments beyond this time may pose risk of brain tissue swelling. Thus, a prediction system must be made to determine the suitability of a stroke treatment to avoid the risk of failure. In this report, a mathematical model based on poroelastic theory and asymptotic expansion homogenization has been developed to study the formation of brain tissue swelling after ischaemia-reperfusion treatment. Firstly, the mathematical model of brain tissue swelling after ischaemia-reperfusion treatment is investigated using an ideal 2D brain geometry. The objective here is to observe the effect of infarct size and location towards the formation and severity of brain herniation, which will form due to brain tissue swelling. However, this model assumed that the blood pressure is constant and homogeneous throughout the brain, while in fact, the blood capillaries vary in sizes and shapes. Therefore, asymptotic expansion homogenization technique is applied to allow for the inclusion of capillaries sizes into the initial model. This method transforms the initial model into two types of equations: (1) macroscale governing equations; and (2) microscale cell problems. In order to solve for the macroscale governing equations, the microscale cell problems must first be solved on a brain tissue geometry to calculate the effective parametric tensors, which later be used in the macroscale governing equations. Lastly, the mathematical model is solved in a realistic brain geometry to evcaluate the effect of different mechanical properties of the brain towards brain tissue swelling formation

Experimental investigation on performance of short pineapple leaf fiber reinforced tapioca biopolymer composites

The performance of short pineapple leaf fiber (PALF) reinforced tapioca biopolymer (TBP) composites were investigated, specifically the effect of fiber length and fiber composition on mechanical properties (tensile properties, flexural strength, and impact strength). Composite samples with different fiber lengths (< 0.50 mm, 0.51 mm to 1.00 mm, and 1.01 mm to 2.00 mm) and different fiber compositions (10%, 20%, 30%, and 40%) were prepared through crushing, sieving, internal mixing, compression molding, and machining processes. The combination of PALF and TBP enhanced the mechanical properties of composites with 30% as the optimum fiber content. However, the influence of different fiber lengths up to 2.00 mm provided no significant effect on producing maximum tensile properties. Good interfacial adhesion between PALF and TBP was evident from scanning electron microscopy analysis. Therefore, the combination of PALF and TBP has great potential as a renewable and biodegradable polymer. Moreover, PALF-TBP composites are expected to become alternatives to petroleum-based polymers

Investigation of the effect of different materials on convective heat transfer

Conventionally, the study of convection heat transfer merely focuses on the behavior of air flow without considering the conductive effect of the horizontal flat plate. However, it is expected that the conductive effect of the horizontal plate somewhat affects the air flow temperature across the flat plate. Therefore, it is motivated to study the variation of air flow temperature across different materials of flat plate in various time frame. The materials used in this study are aluminium, stainless steel and cast iron. Infrared camera and FloEFD simulation software are used to measure the upper surface temperature of the flat plate. For forced convection, the study is carried out within the range of 103 £ Re £ 104 and within the range of 1 × 107 £ Ra < 2.2 × 107 for natural convection. Flow velocity of 2.3 m/s, 4.1 m/s and 5.2 m/s are used for the forced convection. The results showed that aluminium plate cools down faster than the other two metal plates used in all scenarios. Stainless steel’s temperature goes down faster compared to cast iron. These results were supported by the fact that aluminium has higher heat transfer rate of other metals. For forced convection, the discrepancies of temperatures between experimental and simulation studies are below 10%, which demonstrates that the results are reasonably acceptable. For natural convection, even though the discrepancies between simulation and experimental results on temperature variations are relatively large, the temperatures varied in similar pattern. This indicates that the results are reliable

Influence of dammar gum application on the mechanical properties of pineapple leaf fiber reinforced tapioca biopolymer composites

The objective of this work is to investigate the influence of the utilization of dammar gum (DG), which is a biodegradable and renewable binder, on the mechanical properties of short pineapple leaf fiber (PALF) reinforced tapioca biopolymer (TBP). Samples with variable DG concentrations (10%, 20%, 30%, and 40% by weight) and a constant 30% PALF composition were created with varying TBP percentages using an internal mixing process and compression molding. The results showed that PALF-TBP with 10% DG had the highest mechanical properties with tensile, flexural, and impact strength of 19.49 MPa, 18.53 MPa and 13.79 KJ/m2, respectively. Scanning electron microscopy (SEM) images prove the enhanced mechanical characteristics. In addition, Fourier transform infrared spectroscopy (FTIR) analysis showed that the DG improves the matrix and PALF interface. The results show that the utilization of DG significantly enhanced the mechanical characteristics of composites. In addition, it is anticipated that it will be able to create PALF-TBP-DG composites as a potential alternative for conventional polymers in various applications, especially in engineering applications such as automotive and packaging industries. Therefore, it is expected to be capable of contributing to sustainable development goals (SDGs)