Shigeki Tomomatsu

Effect of Material Layers in a Compound Circular Receiver Model Design for Concentrating Solar Power

The present study intends to evaluate heat conductance and mechanical strength at elevated temperature of a prototype of flat type receiver composed of carbon steel fin and copper tubes. Considering a compound circular plate composed of different kinds of material layers as an analytical model of the receiver, a mathematical analysis of plane axisymmetric transient heat conduction and thermal stresses for the plate is developed. Performing numerical calculation for a compound circular plate consisted of carbon steel layer and copper one, the effect of thickness of copper layer on spatial variations and time-evolutions of temperature change and thermal stresses is discussed briefly.

Extraction Method and Evaluation of Shape for Flame Cross Section of Premixed Turbulent Combustion in Constant Volume Combustion Chamber by Image Measurement

To clarify the mechanism of turbulent combustion from a view point of physical data, premixed turbulent combustion in a constant volume combustion chamber was researched. Flame shape was measured as cross sectional image by laser sheet method. The most suitable method for extraction of flame front was examined and flame shape was evaluated as complexity of flame outline by fractal dimension. The results showed that the image processing method using frequency filter was suitable for extraction of correct flame front. Fractal dimension of flame shape was increased by turbulence intensity. Furthermore it was kept constant value at each turbulence intensity during growth of flame.