The design of the botanical indoor air biofilter system for the atmospheric particle removal

Indoor environmental quality (IEQ) objective generally focus on providing energizing and comfortable environments for occupants and minimizing the risk of building-related health problems. Living green walls are natural air-filters that creates a cleaner and revitalizing work environment that will lead to better IEQ. The research presented here describes the design (the new concept) of the botanical indoor air biofilter (BIAB) and modelling conducted to determine the effectiveness of the system in reducing the indoor airborne particulate matter levels. The BIAB was also evaluated for its single-pass filtration for particles ranging in diameter from 2.5 to 10 Μ along with total suspended particles. The system is comprised of three functional components; a region of vertically grown plants as botanical section, an evaporative cooling pad as cooling section (additional section from a commercial BIAB), and a mechanical ventilation system that supply cool filtered air to surrounding. The complete system recorded highest removal efficiencies of 85% for TSP, 75.2% for PM2.5, and 71.9% for PM10. It indicated that with the additional component in the BIAB system (cooling component), it provides enhancement of the particulate removal due to the ability in absorbing the dust particles and filtration dynamics as the polluted air pass through the wetted cooling pad and the light shower of water

Development of a reduced biodiesel surrogate fuel model for multi- dimensional CFD simulations

This work reports the development of a reduced biodiesel surrogate fuel model for multi-dimensional CFD simulations. The model is derived using an integrated kinetic mechanism reduction scheme and the final chemistry comprises only 83 species. The model is first validated in zero-dimensional (0-D) chemical kinetic calculations under a wide range of auto-ignition and jet-stirred reactor (JSR) conditions. The computed ignition delays (ID) and species profiles are in well agreement with those of the detailed model. Besides, the experimental species profiles of rapeseed methyl ester (RME) oxidation in a JSR are also reasonably reproduced. Subsequently, the fidelity of the model is further assessed in two-dimensional (2-D) CFD simulations of a constant-volume combustion vessel with respect to the experimental results of soy-methyl ester (SME) combustion. Comparisons of the computations with the experimental data reveal that ID, lift-off lengths (LOL) and soot volume fractions are reasonably well replicated by the model. Successively, the applicability of the reduced model to serve as a universal surrogate model for other biodiesel feed-stocks, such as palm-methyl ester (PME) and sunflower-methyl ester (SFME), is investigated in both 0-D and 2-D simulations. The compositions of the reduced model are varied according to the saturation/unsaturation levels in each fuel. In this work, it is demonstrated that the reduced model can potentially be used to predict the reactivity of biodiesel feed-stocks with low degree of saturation (≤30%) in both kinetic and CFD spray simulations

Conceptual design of a novel power-augmented hydrokinetic run-of- river turbine

Other than the water stream from ocean, river stream is also being considered as a viable source of renewable energy. Many researchers has approached and started the studies of river stream in order to harness the maximum power from the rivers. River stream offers promising energy especially to the rural areas which are surrounded by rivers. From previous studies, it shows that majority of the hydrokinetic run-of-river turbine systems are designed in vertical and horizontal axis. Besides, some of the vertical and horizontal axis turbines are also enclosed by the duct or diffuser in order to guide the river stream and increase the flow velocity. However, the design of the shape of diffuser faced the challenges during fabrication phase and additional supporting structures are needed during installation, causing the increases in the overall cost. In this paper, the authors would like to propose a conceptual design of a novel power-augmented hydrokinetic run-of-river turbine which utilizes the concept of cross-axis wind turbine and simple augmented guide vane. This conceptual design of hydrokinetic turbine able to capture the advantages of both the horizontal and vertical axis turbines. Helical blade design was chosen for this conceptual design due to its ability to capture the skewed flow created by the difference in velocity of upper and lower faces of turbine. When the vertical-axis turbine rotates, the angle of attack of each blade varies cyclically. The cyclical variation of the angle of attack creates cyclical blade loading, which increases the fatigue experienced by blades. Most of the cyclical loading can be alleviated by using helical instead of straight blades. The conceptual design of this cross-axis turbine with helical blade is similar to the Gorlov helical turbine but there are some differences in the radial blades which are designed as 8 degrees upper and lower respectively to the horizontal axis of the connector hub. The two layers radial blade-rotors are offset by 60 degrees. The turbine system is designed by intercepting the two guide vanes in between three individual turbines and also two diffuservanes as the outer part of the system. The NACA 0015 airfoil profile is used as turbine blade in this design. The construction costs of cross-axis concept turbine and the helical blades are relatively low (about 30%) compared with the huge ducted and diffuser turbine. A 3D model was constructed and simulated by using the computational fluid dynamics software, ANSYS-Fluent. In the simulation, the velocity of water flow and the rotational speed of turbine were increased with the integration of the guide-vane and diffuser features. It is estimated that this conceptual design turbine will achieve 60% increase in energy gain

Impact Force Identification using the Modal Transformation Method in Collocated and Non-Collocated Cases

Previous impact force identification has focused on collocated cases because noncollocated cases tend to be ill-posed. Considering the impact location is inaccessible, impact force identification using remote responses away from the impact location must be developed. This study initiates an effort to examine impact force identification for non-collocated case. A methodology utilizing operating deflection shape analysis, modal analysis and the modal transformation method (MTM) is presented to identify the unknown dynamic force. The performance of this approach is examined via experimental verification. The objective of this study is to examine the effectiveness of impact force identification by using MTM for both collocated and non-collocated cases. By measuring the response and frequency response function of the test rig, the time history of the unknown force is recovered by the force identification method where the impact location is known. The proposed method is examined at Points 1 and 15, which have satisfactory and poor curve fitting results respectively. It is found that force accuracy improves when the curve fitting result is enhanced. Experimental results show that impact force identification via MTM is applicable in both collocated and noncollocated cases, only if the curve fitting results satisfactory

The basics and issues of Thermochromic Liquid Crystal Calibrations

Thermochromic Liquid Crystals (TLCs) have been widely used by researchers in heat transfer and fluid flow communities as a thermal imaging tool for mapping surface and spatial temperature distributions. In order to utilize TLCs for quantitative temperature measurements, calibration is first necessary to determine the colour–temperature relationship of TLCs. This paper is aimed to provide novice and intermediate users of TLCs with a review on the basics and issues pertaining to calibrations of TLCs, particularly for surface thermography. A general overview of TLCs, the basic elements of a TLC calibration rig, and the common calibration methods of TLCs are described. The crucial issues associated with calibrations of TLCs, namely, imaging, colourimetry, illumination, hysteresis, film thickness and aging, and the methods used to compensate for these effects are discussed. This paper is intended to provide useful information to novice and intermediate users of TLCs, particularly on TLC calibrations

Load-displacement behavior of glass fiber/epoxy composite plates with circular cut-outs subjected to compressive load

An experimental study of the behavior of woven glass fiber/epoxy composite laminated panels under compression is presented. Compression tests were performed on to 16 fiber-glass laminated plates with and without circular cut-outs using the compressed machine. The maximum load of failure for each of the glass-fiber/epoxy laminated plates under compression has been determined experimentally. A parametric study was performed as well to investigate the effects of varying the centrally located circular cut-out sizes and fiber angle-ply orientations on to the ultimate load. The experimental work revealed that as the cut-out size increases, the maximum load of the composite plate decreases. Also, it has been observed that cross-ply laminates possess the greatest ultimate load as compared to other types of ply stacking sequences and orientations

Impact of Solidity on the Aerodynamic Performance of Vertical Axis Wind Turbine via 2D CFD Simulation

Research on vertical axis wind turbines (VAWTs) is receiving more attention due to their special characteristic of capturing omnidirectional wind flow. Unlike the horizontal axis wind turbine, the flow characteristic of VAWT is complex, especially in the downwind region. Solidity is one of the design parameters that will affect the wind turbine performance significantly where an optimum solidity provides a wide range of tip speed ratios while achieving a high coefficient of power. This paper presents the effects of the solidity of an H-Darrieus VAWT in terms of varying the number of blades and the chord length by using two-dimensional computational fluid dynamics simulations. The sliding mesh method and the k-ω SST turbulence model were selected to model the rotational motion of the NACA0021 airfoil VAWT. The reliability of the simulation was first validated with the data available in the literature where a good agreement is presented. In this study, the coefficient of torque, CT and coefficient of power, CP for various tip speed ratios (TSRs) were analysed at different VAWT solidity. The results show that when the VAWT solidity increases, the maximum CP increases up to an optimum point and shifts to a lower TSR, which links the aerodynamics performance and the vortices shedding on the blades. Also, it was noted that the self-starting ability of the rotor is highly affected by the solidity and is dependent on the initial starting orientation. The simulation results can serve as a reference in determining the solidity when designing a VAWT with a target TSR range

Analysis of the Polypropylene-Based Aluminium-Air Battery

Global energy demand is rising due to the rapid development and adoption of new technologies in every sector. Hence, there is a need to introduce a clean energy source that does not cause damage to the environment. Aluminium-air battery with its high theoretical specific volumetric capacity is an exciting alternative for post-lithium energy storage and has been at the forefront of energy research for years. However, the conventional aqueous electrolyte-based aluminium-air battery with bulky liquid storage, parasitic corrosion of aluminium in contact with the electrolyte, and formation of a passive oxide or hydroxide layer has precluded its widespread application. In order to achieve successful simplification and cost-effectiveness, a novel idea of a polypropylene-based aluminium-air battery is proposed. In this work, a polypropylene-based aluminium-air battery was constructed using aluminium foil as an anode, carbon fiber cloth as an air-cathode, and Polypropylene and Kimwipes as the separator. The effects of the electrolyte concentration on the aluminium-air battery were investigated and analyzed using various discharge currents. The study showed that the performance of the polypropylene separator is better than that of the Kimwipes separator. The battery capacity is negatively correlated with the concentrations of the electrolyte. At a discharge current of 30 mA, the aluminium-air battery has a specific capacity of 375 mAh g−1 when 1 M of potassium hydroxide was used as electrolyte

Impact Force Identification using the Modal Transformation Method in Collocated and Non-Collocated Cases

Previous impact force identification has focused on collocated cases because noncollocated cases tend to be ill-posed. Considering the impact location is inaccessible, impact force identification using remote responses away from the impact location must be developed. This study initiates an effort to examine impact force identification for non-collocated case. A methodology utilizing operating deflection shape analysis, modal analysis and the modal transformation method (MTM) is presented to identify the unknown dynamic force. The performance of this approach is examined via experimental verification. The objective of this study is to examine the effectiveness of impact force identification by using MTM for both collocated and non-collocated cases. By measuring the response and frequency response function of the test rig, the time history of the unknown force is recovered by the force identification method where the impact location is known. The proposed method is examined at Points 1 and 15, which have satisfactory and poor curve fitting results respectively. It is found that force accuracy improves when the curve fitting result is enhanced. Experimental results show that impact force identification via MTM is applicable in both collocated and noncollocated cases, only if the curve fitting results satisfactory