DIGITAL EQUIPMEMT 



CENTRAL 

 PROCESSING " 

 UNIT 



DIGITAL 

 TO ANALOG 

 CONVERTER 



ii---iir ." 



CHANNEL 

 SELECTION 

 CIRCUITRY 



STRIP CHART 



LINES SELECTTO 



TOR OISPLAX ANO 



RECORDING 



OUTPUT 



CONTROL 



LINES 



CHANNEL 

 SELECTION 

 CIRCUITRY 



WAVE ROD AND 

 POTENTIOMETER 

 LINE PAIRS FOR 

 EACH WAVE STAND 



WAVE STAND 

 CALIBRATIOH 

 STAILIS UOHTS 



PROGRAMS, 



TEST PARAMETERS, 



AND DATA 



WAVE GENERATOR 



Figure 17. Automated Data Acquisition and Control System 



A water circulation system (Figure 15), consisting of a 20.3-cm (8-in.), 

 perforated-pipe water-intake manifold, a 0.28-cms (10-cfs) pump, and sonic flow 

 transducers with a multiprocessor transmitter, was used in the model to reproduce 

 steady-state flows through the St. Clair River that corresponded to selected 

 prototype flows. The magnitudes of these currents were measured by timing the 

 progress of weighted floats over known distances. 



A 0.6-m (2-ft) (horizontal) solid layer of fiber wave absorber was placed 

 along the inside perimeter of the model to dampen wave energy that might 

 otherwise be reflected from the model walls. In addition, guide vanes were placed 

 along the wave generator sides in the flat pit area to ensure proper formation of 

 the wave train incident to the model contours. 



Design of tracer material 



As discussed previously, a fixed-bed model was constructed and a tracer 

 material selected to qualitatively determine movement and deposition of sediment 

 in the vicinity of the harbor. Tracer was chosen in accordance with the scaling 

 relations of Noda (1972), which indicate a relation, or model law, among the four 

 basic scale ratios, i.e., the horizontal scale, X ; the vertical scale, |j. ; the sediment 

 size ratio, r]^ ; and the relative specific weight ratio, r|. . These relations were 



34 



Chapter 6 Physical Model 



