Browsing by Author "Chamath, LG"

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item: Conference-Full-text
Evaluating the thermal conductivity of three-phase insulation composite using analytical and numerical methods
(IEEE, 2022-07) Chamath, LG; Srimal, LKT; Sewvandi, GA; Rathnayake, M; Adhikariwatte, V; Hemachandra, K
Sustainable insulation materials have been more attractive in the last two decades due to biodegradability, low embodied energy, availability, and non-toxicity. Those materials are primarily fabricated as composite materials using natural plant fibres. Then, the material contains three phases, i.e., fibre, binder, and air void. The volume fraction of each phase will decide the material’s insulation properties and can be analyzed using experimental, analytical, and numerical methods. Numerical and analytical methods are more attractive compared to experimental methods due to cost-effectiveness and less time consumption. However, only a limited number of studies have attempted to find the effective thermal conductivity (K eff ) of a three-phase composite by these methods. In this study, the authors have suggested a plan to find the K eff of this composite using a numerical method and validated through the analytical techniques. This study, coir fibre was used as a fibre material and latex as a binder material. The results show that the numerical model should be changed based on the air void fraction. It was concluded that the close-pores structure model applies to the pore volume fraction of 0.65 and the open-pores structure model for pore fractions above 0.65 for numerical analysis.
item: Conference-Abstract
Solar powered mini air conditioner for automobiles
(Society of Materials Engineering Students, Department of Materials Science and Engineering, University of Moratuwa, 2017-03) Gunawardhana, HPB; Chamath, LG; Galhenage, AS; Sivahar, V
As a tropical country, Sri Lanka experiences sunny conditions throughout the year. Most of the time vehicle users find it difficult to obtain shady places for their parking purposes. The temperature rise of the automobiles parked in sun is a critical issue which creates uncomfortable feelings for the passengers. Here we develop an affordable mini air conditioning system for the automobiles. The heat buildup in inside of the vehicle is fully investigated and the energy requires for cooling is also estimated. Solar energy is the most effective renewable energy source for countries like Sri Lanka. In this study, sustainable solar energy is used to maintain the vehicle inside temperature during the parking. Our design project is based on the photovoltaic system and the comfortable temperature is created by using a solar powered mini air conditioner. Our finding provides an attractive solution for this uncomfortable situation. Furthermore, the result of this study can be used by heating ventilating and air conditioning engineers to design more efficient air conditioning systems for different applications.