In this paper, heat transfer and fluid flow of natural convection along an inclined flat plate were investigated experimentally. Local heat transfer coefficients were measured in a wide variety of inclination angles at first. The results showed that the heat transfer rates for an inclined surface became larger than those for a vertical surface.
Then, the surface temperature patterns were also visualized by liquid crystal sheet. It was revealed from the visualization that the low temperature streaks appeared on an inclined surface and they played a significant role on heat transfer. Such low temperature streaks were similar to the streaky structure that was observed in turbulent natural convection along a vertical flat plate.

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In image processing of two-dimensional flows, correlation method is widely used to estimate the velocities of the flows. However, it has been pointed out that the method often provides erroneous velocities for disturbance flows. In this paper, we discuss the correction of the erroneous velocities. Considering the relation between the sampling time and the erroneous velocities, we propose to correct the error by effective use of additional images sampled between the original ones. In addition, we propose an alternative method which does not require the additional images. This method is based on the fact that the size of the matrix for the computation of the correlation is essential for the correct estimation. The correction of the erroneous velocities is achieved by adjusting the size of the matrix according to flow patterns. Experimental results are presented to confirm the validity of the proposed methods.

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