located on the right and left sides of the power jet through the 

 cover plates by means of a dye injection pump system. Due to submerged 

 nature of the power jet the dye solution was trapped by the entrained 

 flow thereby making the flow pattern in the element visible. The 

 technique was very successful in revealing the power jet boundaries. 

 Photographs of the flow pattern were taken by mounting a camera directly 

 above the element. 



Test Results 



Some modifications in the location of the control port and in the 

 shape of the power jet separation surface resulted from the tests. The 

 width of the active leg flow passage was reduced to % inch. All modi- 

 fications that were necessary for the proper functioning of the element 

 are shown in a sketch (Figure 7) . Table 1 lists the dimensions of the 

 various parameters of the element after modifications. The flow through 

 the active and passive leg of the modified element changed which resulted 

 in new flow Reynolds numbers (22000 range) . A typical flow pattern through 

 the element for flow rates of 4.0 gpm and 3.5 gpm through its active and 

 passive legs respectively with no control flow is shown in Figure 8. 



Power Jet Deflection Characteristics 



Tests to obtain jet versus control flow characteristics were 

 conducted on the modified element. Altogether four series of tests, with 

 different combinations of active and passive leg flows (Table 2) were 

 run. For each series the control flow was varied discretely from zero 

 to some value which deflected the power jet by 20 . For each observation 

 a photograph of the flow pattern through the element was taken for record 

 and analysis. Out of a total of 26 pictures taken, 12 are included in 

 the report for illustration (Figures 8 through 19) . During the experi- 

 ments it was observed and is apparent from the flow pattern photographs 

 that the flow through the element was highly turbulent. It was further 

 noticed that the maximum sensitivity of the power jet occurred at flow 

 rates of 5.0 gpm and 4.0 gpm through the active and passive legs 

 respectively. 



Further, the power jet deflection was measured from the flow 

 pattern photographs for each test series. In addition to this the 

 power jet width was measured at distances of three and four inches 

 from the interaction zone of the supply flows. Table 3 lists the power 

 jet deflection and its width for the entire test series. Furthermore, 

 to determine the trend in the experimental data, the jet deflection, 

 A'!*, was plotted against Q /Q for each Q /Q (Figure 20). l-flnere Q , 

 Q , and Q are the flow rates through the passive and active legs, 

 and through the control port of the element respectively. It should 

 be noted from Figure 20 that these characteristics are nearly straight 

 lines and the maximum sensitivity of the power jet occurs for 



