2 Tests and Results 



Stability Scale Effects 



If the absolute sizes of experimental breakwater materials and wave di- 

 mensions become too small, flow around the armor units enters the lami- 

 nar regime; and the induced drag forces become a direct function of the 

 Reynolds number. Under these circumstances prototype phenomena are 

 not properly simulated, and stability scale effects are induced. Hudson 

 (1975) presents a detailed discussion of the design requirements necessary 

 to ensure the preclusion of stability scale effects in small-scale breakwater 

 tests and concludes that scale effects will be negligible if the Reynolds sta- 

 bility number (Rj^) expressed in the equation below is equal to or greater 

 than 3 x lO'*. 



1/2 „'/i , 



where 



g = acceleration due to gravity, ft/sec 



H = wave height, ft 



1 ^ = characteristic length of armor unit, ft 



V = kinematic viscosity 



For all tests reported herein, the sizes of experimental armor and wave 

 dimensions were selected such that scale effects were insignificant (i.e., 

 Rj^ was greater than 3 x lO"*). 



Chapter 2 Tests and Results 



