To predict the blade performance of a Darrieus-type cross-flow water turbine, aerofoil data obtained by a blade at rest in a uniform steady flow have been unavoidably used, though a Darrieus blade has a circular motion so that characters of flow around both blades are quite different. The authors presented a method which related both flow fields in a preceding paper, but it was still insufficient in its theoretical basis. Then, a complementary study on this problem was carried out by inviscid flow analysis. Calculated results showed that the fluid forces generated by velocity distribution along a Darrieus blade surface were much larger than the other additional forces created by the circular motion of a blade. It was clarified that a flow around a blade in a circular motion could be transformed approximately to a flow around a blade in a rectilinear motion by the use of an equivalent circular camber and an equivalent angle of attack, with the condition that the angle between the resultant force and camber line of the blade was mutually equal in both flow fields.
|ジャーナル||Transactions of the Japan Society of Mechanical Engineers Series B|
|出版ステータス||出版済み - 1987|
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