Enhancement of Wind Turbine Aerodynamic Performance Using New Designed Airfoils

The rotor is the first element in the chain of functional elements of a wind turbine. Therefore, its aerodynamic and dynamic properties have a decisive influence on the entire system in many respects. The capability of the rotor to convert a maximum proportion to the wind energy, flowing through its swept area, into mechanical energy is obviously the direct result of its aerodynamic properties. These will determine the overall efficiency of the energy conversion in the wind turbine. To enhance the performance of wind turbine, one has to analyze the effects of variations in nomenclature of a rotor blade on the performance of wind turbine. The present paper incorporates the analysis of primary selected blade design by the Solar Energy Research Institute (SERI -8) with BEMT based simulations; five different suggested models of the rotor blade are also analyzed with same BEM based simulations, including Tip losses, 3-D corrections and Reynolds number drag correction. These six models incorporate twist optimization, chord distribution optimization, and the combination of airfoils, new designed airfoils and base model SERI-8 rotor blade. Without modifying the size of the rotor blade, different analysis is done and improved the rotor aerodynamics efficiency. Highly aerodynamics efficient new designed airfoils produce more lift and minimize the drag by avoiding the stall; it develops high-value of coefficient of lift to drag (Cl/Cd) ratio. The rated power for all models considered at 15m/s for analysis. The result suggests that the rotor power efficiency is 25.772% with SERI-8, 29.420% with the twist optimized model, 55.51% with the model with a combination of SG series and SERI series airfoils and 61.62% with new designed airfoils (SV Series) model. Respectively, efficiency is increased by 3.64%, 29.745%, and 35.84% compared to SERI-8 blade.

ADVANCED SOLAR ASSISTED DRYING SYSTEMS FOR MARINE AND AGRICULTURAL PRODUCTS

Solar assisted drying systems are cost effective and suitable for drying of various marine andagricultural products. The way forward for advanced solar assisted drying systems is compact collector design,high efficiency, integrated storage, and long-life systems. Air based solar collectors are not the only availablesystems. Water based collectors can also be used whereby water to air heat exchanger can be used. The hot airfor drying of agricultural produce can be forced to flow in the water to air heat exchanger. The hot water tankacts as heat storage of the solar drying system. Heat pump drying system can be effective use for as part of solarassisted drying systems. Moreover, innovative applications of photovoltaic thermal system for simultaneousproduction of heat and electricity are suitable as standalone applications and totally operated on solar energy.The Solar Energy Research Institute has developed four advanced solar assisted drying system suitable fordrying of various marine and agricultural products namely (a) the solar assisted drying systems with thedouble-pass solar collector with fins (b) solar assisted dehumidification system (c) solar assisted chemical heatpump system and (d) solar assisted heat pump with photovoltaic thermal collectors.DOI: http://dx.doi.org/10.3329/jme.v42i1.15912

Thermal Comfort Assessment at Parcel and Logistic Industry: A Field Study in Malaysia

This paper presents the workers thermal sensation votes and perception of the thermal environment in air conditioning at one of the workspace in Malaysian parcel and logistic industry. The environment factors examined was the relative humidity (%), wind speed (m/s), air temperature (C) and CO2 (ppm) of the surrounding workstation area. These factors were measured using custom integrated thermal comfort apparatus namely as Thermal Comfort Equipment developed by Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia, which is capable of measuring various environmental factors. The time series data of fluctuating level of environment factors were plotted to identify the significant changes and patterns among the factors. Then the thermal comfort of the workers was assessed by using ISO Standard 7730 and thermal sensation scale by using Predicted Mean Vote (PMV). Further Predicted Percentage Dissatisfied (PPD) is used to estimate the thermal comfort satisfaction of the occupant. Finally the PMV and PPD were plotted to present the thermal comfort scenario of workers involved in related workspace. The results revealed that the thermal comfort at the particular workplace was warming followed by thermal sensation and likely to be dissatisfied by dominant of occupants. The results also indicated that the CO2and index of clothing (clo) dominated the parameters of comfort to the occupants.