Information on the detailed distribution of loads (or pressures) is necessary 

 in both uniform flow and inclined flow in order to isolate the reasons for the 

 under -pr edict ion of the periodic propeller blade loads in inclined flow and the poor 

 prediction of time-average propeller blade loads at substantially off-design 

 conditions. This further information is necessary in order to provide guidance for 

 improving the analytical predictions. To the author's knowledge, no detailed 

 reliable information of this type is presently available. 



A number of attempts to measure the pressure distribution on marine propellers 



have been reported. These attempts are summarized in Table 1. As outlined in 



Table 1, several techniques have been used including air or water tubes leading to 



either manometer tubes ' or remote pressure transducers, and pressure trans- 



17—18 

 ducers in the blade including transducers which extend beyond the blade surface, 



1 q nn <-j / 



fully-embedded flush-mounted transducers, and transducers embedded in cavities 

 in the blades with a small hole to the blade surface. Various experiments have been 

 conducted in wind tunnels, water tunnels, and towing tanks in both uniform flow and 

 circumf erentially nonuniform flow. 



All of these data have shortcomings of commission or omission, and thus their 



accuracies are suspect to varying degrees. None of the generally available docu- 



9-23 

 mentation of pressures measured on marine propeller blades describes the 



experimental procedure in sufficient detail to demonstrate the experimental accuracy. 



21 

 Further, none of these documents, except the paper by Takei et al., describes the 



propeller geometry in sufficient detail to allow one to theoretically calculate the 



pressure distribution. 



Therefore, an experimental program was undertaken in an attempt to obtain 



accurate and reliable measurements of the pressure distribution on CP propellers in 



uniform and inclined flow over a range of advance coefficients. This report presents 



results from the program. The results of some exploratory experiments conducted 



under this program were reported in Reference 25. Experimental data are presented 



from uniform and inclined flow configurations over ranges of advance coefficient 



and Reynolds numbers. Steady and unsteady pressure coefficients are presented and 



compared to theoretical predictions. 



