Low Aspect Ratio Blades Research Articles

Theoretical Research on Propeller Type Current Meters

This paper reports the analytical results of the motions of current meters with low aspect ratio blades. Results obtained tell that calculation values of the lifting surface theory coincide with experimental results at apparent runaway speed of all runners. If the results of the lifting line theory are compensated, calculation results of each high pitch model nearly become equal to each experimental value. Moreover, constant pitch meters show better characters than variable pitch meters, concerning velocity fields around runner blades. From the foregoing results, the fundamental equations of the current meter runner designs are brought out.

Use of two-dimensional unsteady flow theory with low aspect-ratio blades

It is known that if two-dimensional aerofoil theory is used to calculate the mean forces on a marine propeller blade, the answer obtained is likely to over-estimate the true answer by a factor of typically three. It is shown that when unsteady forces

Pseudo-Static Deformation and Frequencies of Rotating Turbomachinery Blades

I this paper a method based on the finite element technique is developed for calculating the natural frequencies and mode shapes of rotating low aspect-ratio blades. The blade is treated as a shell. A study of the effect of different parameters such as pretwist, speed of rotation, disk radius and setting angle on the pseudo-static deformation, caused by the centrifugal forces, and the natural frequencies of the blade, is made.