Research has been performed to determine the accuracy of neutrally buo
yant and near-neutrally-buoyant bubbles used as flow tracers in an inc
ompressible potential flowfield. Experimental and computational result
s are presented to evaluate the quantitative accuracy of neutrally buo
yant bubbles using a commercially available helium bubble generation s
ystem. A two-dimensional experiment was conducted to determine actual
bubble trajectories in the stagnation region of a NACA 0012 airfoil at
0-degrees angle of attack. A computational scheme evaluating the equa
tion of motion for a single bubble was also used to determine the fact
ors which affect a bubble's trajectory. The theoretical and computatio
nal analysis have shown that neutrally buoyant bubbles will trace comp
lex flow patterns faithfully in the flowfield of interest. Experimenta
l analysis revealed that the use of bubbles generated by the commercia
lly available system to trace flow patterns should be limited to quali
tative measurements unless care is taken to ensure neutral buoyancy.