The Effect of Additives on Fluid Friction 



The experiments shown in Table 4 were not intended to be rigorous, or even 

 very quantitative, but simply tests to show the possibility that organic materials 

 similar to those which might be present in towing tanks or other hydrodynamic 

 facilities would aifect the measured drag. 



Table 4 

 Drag Reduction of Living Materials 



The experiments shown in Table 4 were not intended to be rigorous, or even 

 very quantitative, but simply tests to show the possibility that organic materials 

 similar to those which might be present in towing tanks or other hydrodynamic 

 facilities would affect the measured drag. 



From Table 4 it is seen that sizeable reductions in drag can be obtained 

 from a variety of natural substances. While concentrations required for signifi- 

 cant effect were high enough that the contamination was apparent in these tests, 

 it is conceivable that other, more effective natural contaminants may occur 

 which approach the synthetic polymers in effectiveness at very low concentra- 

 tions. The search for such contaminants in tank water at the time of such a 

 drag reduction excursion must be directed at concentrations of a few parts per 



955 



