Lift and Drag Effects Due to Polymer Injections on the Surface of Symmetric Hydrofoils
HYDRONAUTICS INC LAUREL MD
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Experimental results are presented for the effects on the lift and drag on symmetrical hydrofoils due to the injection of dilute polymer solutions on to their surfaces. Results are presented for three different polymers, namely, Polyox, Polyacrylamide and Jaguar for purposes of comparison, results are also presented for water injection. The results indicate that while, in general, polymer injection leads to a reduction in drag, the lift can either increase or decrease depending on the polymer, the angle of attack, the surface on which the injection is made, the chordwise location at which injection is made and the injection velocity. Results for the effects of the injections on the pressure distributions on the hydrofoil are also presented, and these results are consistent with the force measurements. Tests on the effects of simultaneous injections from several chordwise locations indicate that significant reductions in drag can be achieved by a judicious choice of the locations.
- Marine Engineering