INVESTIGATION OF WAVE EFFECTS PRODUCED BY A THIN BODY 

 TMB MODEL 4125 



by 



Georg P. Weinblum, Janet J .Kendrick, and M .Allison Todd 



INTRODUCTION 



An opportunity to check experimentally Michell's wave-resistance theory 1 arose when 

 a friction plane or "thin body" was constructed for investigations of the frictional resistance 

 of painted surfaces . In his wave-resistance theory, the only assumption made by Michell as 

 to the form of the ship was that the inclination of the tangent plane at any point of its surface 

 to the vertical median plane should be small . 



Although the TMB model is quite narrow, it cannot be considered as a thin plank; thus, 

 appreciable wave effects must be expected when the model is towed at medium and high 

 Froude numbers . 



• The dimensions of the body are shown in Figure 1. It has a parallel middle body and 

 parabolic ends with vertical sides. Apart from the rectangular form of the sections, this body 

 forms an ideal Michell's ship as defined above due to its very low beam-length ratio 

 [B/L = 0.0265] and beam-draft ratio [B/H = 0.183]. 



Figure 1 - Shape and Dimensions of Friction Body, TMB Model 4125 



L = total length = 252 inches 



I = parabolic length = 66 inches 



B = maximum beam = 6. 69 inches 



b = half beam = 3.345 inches 



H = draft 



= 36 inches 



a = half parallel length 



= 60 inches 



p= 2a/L 



= 0.4762 



References are listed on page 14. 



