2004 Volume 47 Issue 155 Pages 59-65
Thrust and torque generated by a model rotary wing were measured at an ultra-low Reynolds number, Re=4×103, for various aspect ratios with and without linear blade twist. The measured characteristics were compared with those calculated by the method which is well known to be effective for analyzing a rotary wing at a high Reynolds number. The method combines annular momentum theory and blade element theory. This calculation method can give the quantitative explanation of the effects of the aspect ratio and of linear blade twist on the characteristics of the rotary wings. The calculation results also indicate that the present calculation method has the capability of giving an accurate quantitative estimation of rotary wing performance with the blade aspect ratio larger than 10, operating at the ultra-low Reynolds number.