A series of four propellers with different skewback angles and different blade area ratios was designed. The models of these propellers were manufactured and fitted with strain gages. Blade stresses were measured in a cavitation tunnel under a variety of working conditions including the simulation of a crash stop manoeuver. The results are presented as principal stresses normalized by their scaling factor. The second part of this paper concerns finite element calculations. The calculation method employed was validated by comparisons between measured and calculated stresses. Hereafter a number of different blade shapes was treated as well. The influence of blade area ratio, total skew back and other design parameters on blade stresses was evaluated and is discussed in the paper. It was found that the total skew angle mainly influences stress peaks at the trailing edge. The influence of the expanded area ratio is not very significant. To prevent blade failures in a high skew design it is recommended to strengthen the entire profile sections on the outer radii.

Keywords:
measuring point, calculation, stress peak, back side, propeller 2244, total skew angle, propeller 2245, design point, coefficient, skew angle
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Copyright 1991, The Society of Naval Architects and Marine Engineers
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