coefficient of an element of the propeller which is related to an increment of the 

 bound circulation at any radius be independent of the radius for optimum conditions. 

 There are several attempts found in literature to establish F(x) on a basis of this rule, 

 see [27], [23] and [28], from which the form 



X s 



F(x) =—4>{w{x), t(x)] (30) 



x 



follows. In the opinion of the author, however, the assumptions made in the afore 

 mentioned papers include oversimplifications so that the results can not yet be con- 

 sidered final. 



This is about the status to which the theory of marine propulsion is developed 

 today. Improvements which are desirable have been mentioned in the paper. It is 

 essentially the theory of interaction which needs to be extended whereas the propeller 

 theory has been developed in a sufficiently general form, in the opinion of the author. 

 In particular, the effects of non-homogeneties of the wake, including effects from the 

 rudder need further considerations. This point is essential. In addition, the hull- 

 propeller interaction effect of the unsteady relative propeller flow arising from a finite 

 number of blades in a non-homogenous wake should be investigated. 



BIBLIOGRAPHY 



1. KAWADA, S.: 



Journ. of the Faculty of Engr., Tokyo, Imp. Univ., Vol. 20 (1933). 



Journ. Aeron. Sciences, Vol. 3 (1936). 



Aeron. Res. Inst.. Tokyo. Imp. Univ., No. 172 (1939). 



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Deutsche Luftfahrtforschung, Unters. u. Mitteil. No. 1020 



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Soc. Nav. Arch, and Marine Engin., New York, Vol. 60 (1952). 

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Handb. der Physik, Vol. VII. Springer (1927). 



8. GOLDSTEIN, S.: 



Proc. Roy. Soc, London, A., Vol. 123 (1929). 



9. LUDWIEG, H. AND GINZEL, J.: 



Aerodyn. Versuchsanstalt, Gottingen, Rep. 44/A/08 (1944). 



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Taylor Model Basin, Washington, D. C. Rep. 942 (1955). 

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Zeitschr. f. angew. Mathem. u. Mech., Vol. 35 (1955). 



164 



