For the direct numerical simulation with the adapted algorithm, there is a positive relation between the initial distances to the source and the running time, which holds for rc">rmulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0377042716302746&_mathId=si53.gif&_user=111111111&_pii=S0377042716302746&_rdoc=1&_issn=03770427&md5=cf6e218c02bc9cb79d507fc7d2495150" title="Click to view the MathML source">Re=5600r hidden"> but which is not observed at rc">rmulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0377042716302746&_mathId=si54.gif&_user=111111111&_pii=S0377042716302746&_rdoc=1&_issn=03770427&md5=1d12cb18cdf8a76fb5cd71500efb49d4" title="Click to view the MathML source">Re=28000r hidden">. This is caused by the low Schmidt number and the high velocity, which leads the searcher to the source very fast after the first detection of a high concentration level.
The search algorithm is also tested in reverse to detect whether a fluid is well-mixed. The time required for a detection of a too high or low concentration and the number of detections are used as measures for success. By applying the algorithm to some prescribed concentration distributions in two dimensions, it is found that the method is very sensitive to the threshold values for the mixing indicators.