Wave Resistance 



Experience in analyzing experimental results has revealed some difficulties, and 

 Ref . [3] describes a new method of solution which overcomes these. This new 

 method uses Fourier analysis to solve the equations and is particularly effective 

 in absorbing measured results covering a wide range of speeds. A practical ex- 

 ample of a successful application to experiments by Everest on a fine model 

 (Ref. [4]), is discussed in Ref. [3]. 



SKETCH OF NEW METHOD 



The simultaneous equations relating source strength M^ and positions 

 (x^, 0,z^) with measured free-wave amplitude (according to linear theory for 

 deep water) are 



2^e-^%^/^ 



b / k2 



cos(a„x,) = — - 2 - \ A„ 



lOTT- \ „ 2 



L- 



r -z, a ^/k 



^ n r^ 167T ' ' - 



(1) 



where 



is the speed of travel of the array, 

 are longitudinal coordinates, 

 are vertical coordinates, 



a^ = k sec e^, 



^n = Angle of propagation of nth wave component, 

 b = Tank width, 



An' ^n are measured wave amplitudes. 

 Let (1) be rewritten as 



/ \ + 1 COS 





77r\ 



— ■ "• 



Aa/ 



k2\ , .2/k 



'°^^^=Ti; l2--)Ane 



b / kM z„ <^Vk 



(2) 



1558 



