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a b s t r a c tOcean thermal energy conversion (OTEC) is a potential source of renewable energy. In order to design a turbine for maximizing the output power for very low working temperature application like OTEC, careful one-dimensional design followed by detailed three dimensional simulation is required. In this work a radial-inflow turbine with R-22 as working fluid is designed for a closed-cycle ocean thermal energy conversion plant of 2 kWe capacity. Design speed of the turbine is 34000 rpm. Inlet and outlet temperatures of designed turbine are 24.5 C and 14 C respectively. Three-dimensional fluid flow analysis inside the turbine at design and off-design conditions were carried out. Important dimensions of the turbine are: rotor tip and shroud radii of 24 mm and 19 mm respectively; blade widths at rotor inlet and outlet of 6 mm and 11 mm respectively; axial length of 17.5 mm; diffuser of 62 mm long. Volute casing designed has a circular cross section. The importance of the number of blades, blade filleting and stagger angle from the point of view of turbine performance are reported.

The thermal performance of the airflow window systems was studied numerically using the finite-volume method. Effort was directed towards the reduction in space cooling load for the exhausting and the semiexhausting triple-glazed airflow windows. The effects of various parameters such as exhausting airflow rate, solar insolation, and aspect ratio were presented. Some qualitative and quantitative comparisons between two systems were made. It was disclosed that the space-heat gain was considerably reduced by increasing the exhausting airflow rate, and the decrease in the space-heat gain of the semi-exhausting airflow window was larger than that of the exhausting airflow window by about 10 W throughout most of the Re range (except the range of near Re ¼ 0) of this numerical work.

In this paper, the heat transfer characteristics of a self-oscillating heat pipe are experimentally investigated for the effect of various working fluid fill charge ratios and heat loads. The characteristics of temperature oscillations of the working fluid are also analysed based on chaotic dynamics. The heat pipe is composed of a heating section, a cooling section and an adiabatic section, and has a O. 002m internal diameter, a O. 34m length in each turn and consists of 19 turns. The heating and the cooling portion of each turn has a length of 70mm. A series of experiments was carried out to measure the temperature distributions and the pressure variations of the heat pipe. Furthermore, heat transfer performance, effective thermal conductivity, boiling heat transfer and condensation heat transfer coefficients are calculated for various operating conditions. Experimental results show the efficacy of this type of heat pipe. A : Flux area of the heat pipejrn"] As : Heat transfer area of a heating section [m 2 ] A e : Heat transfer area of a cooling section [m 2 ] g : Acceleration due to gravityjm/s"] hs : Mean boiling heat transfer coefficient [W/ m 2 K] he : Mean condensation heat transfer coefficient [W/m 2K] keff : Effective thermal conductivity [W /mK] L : Length of heat pipe [m] N : Raw number of heat pipe P : Pressure CPa] Q : Heat load [W] q : Heat flux [W /m 2 ] rMAX : Max. diameter of pipe [m] • Corresponding Author, Tc : Mean temperature of a cooling section [OC] TE : Mean temperature of a adiabatic section [OC] T H : Mean temperature of a heating section [OC] a : Fill charge ratio of working fluid [%] PI : Liquid density [kg/m"] pv : Vapor density [kg/m"] a : Surface tension [Nz'm]

We introduced the motion capture system using two CCD cameras recently, but could not show any better accuracy than a system using PSD camera. In this paper, we propose two kinds of method to improve the accuracy of the 3D acquisition of the motion capture system using CCD cameras. The applied methods are a distortion removal and z-axis adjustment. We show the result how much the accuracy on the 3D acquisition system improved through comparing with the previous system