(1) the change in Reynolds number and the corresponding reduction in 
relative boundary layer thickness and (2) the effect of the propeller suc- 
tion on the boundary layer and thereby the wake pattern in propeller disk. 
Although these two factors may be important for full-form ships such as 
cargo ships, they are probably not important for high-speed transom stern 
ships of the type under consideration in this report. 
Existing measurements which give information on unsteady blade load- 
ing include: 
1. Measurements of strain on the blades of the model propellers or 
full-scale propellers. However, some calculations and assumptions are 
required to convert measured strains into loads. Published data of this 
type have been summarized by Moyne 
2. Measurement of bearing (shaft) forces and moments on model pro- 
pellers operating in wakes generated by model hulls or wire grid screens. 
However, these experiments give information on only some components of 
blade loading and on only those harmonics of shaft rotational speed cor- 
responding to nZ-1, nZ, and nZ+l, where n is an integer and Z is the 
number of blades. Measurements of this nature have been conducted by many 
investigators, as summarized by Baseline and Weceldenatue 
3. Measurements of forces and moments on individual blades of model 
propellers operating in wakes generated by model hulls or wire grid 
15 
screens. Measurements behind model hulls have been made by Huse and 
5 
Micrel measurements behind screens have been made by Hawdon et al, 
Batieynen K., "Propeller Manufacture - Propeller Materials - Propeller 
Strength," International Shipbuilding Progress, Vol. 22, No. 247, pp 7/- 
102 (March 1975). 
te enendenal R., "Comparative Tests on Vibratory Propeller Forces," 
Proceedings of the Thirteenth International Towing Tank Conference, 
Report of the Propeller Committee, Appendix 2a, Vol. 2, pp 482-494 (1972). 
THe, E., "An Experimental Investigation of the Dynamic Forces and 
Moments on One Blade of a Ship Propeller," Proceedings of the Symposium on 
Testing Techniques in Ship Cavitation Research, The Norwegian Ship Model 
Experimental Tank, Trondheim, Norway, Publication No. 99, Vol II, pp 19- 
188 (December 1967). 
6 
Blaurock, J., "Propeller Blade Loading in Nonuniform Flow," The 
Society of Naval Architects and Marine Engineers, Propellers 75 Technical 
and Research Symposium S-4, Paper No. 4, pp 4/1-4/17 (February 1976). 
