Hydrofoil Motions in a Random Seaway- 

 Table 3 

 Relationship Between Model and Full Scale Response 



If R^ is the ratio between the craft reference lengths and R^ is the ratio 

 between the reference velocities, then R^ = R^^ (Froude scaling). Thus 

 when model response is shown in a particular seaway then the full scale 

 motions relative to the model, in an equivalent seaway, are as follows: 



1. FHE-400 will experience linear motions R^ times those of the model. 



2. FHE-400 linear velocities will be yi^ times those of the model. 



3. FHE-400 linear accelerations will be identical with those of the model, 



4. FHE-400 angular excursions will be identical with those of the model. 



5. FHE-400 angular velocities will be l/v^ times those of the model. 



6. FHE-400 angular accelerations will be l/R^ times those of the model. 



7. Events will happen l/V^ times as fast for FHE-400 than for the model. 



Further studies are continuing on detail stability and control characteris- 

 tics, including hydroelastic effects, stability augmentation system response, and 

 towed body effects. A control console has been installed with the analog com- 

 puter equipment and allows "manual" operation of steering, roll and throttle 

 controls for realistic simulation of rough water operation, takeoff and landing 

 and turning maneuvers. 



While it is hoped that the depth of the programme described will have en- 

 compassed most of the problem areas, final proof will rest with sea trials of 

 the prototjrpe ship. 



SYMBOLS 



A = rolling inertia (slugs, ft 2) 

 B = pitch inertia (slugs, it^) 

 b = foil immersed span (ft) 

 c - foil chord (ft) 

 C - yaw inertia (slugs, ft ) 

 D = operator d/dt 

 D = product of inertia (slugs, ft^) 

 E = product of inertia (slugs, ft-^) 

 F = product of inertia (slugs, ft^) 



647 



