Themotionofionsatatmosphericpressureisgovernedbyelectricalfield-andviscousdrag-forcestoacomparableextent. Thusacomprehensivedescriptionoftheconditionsinanatmosphericpressureionsourcehastoincorporatethe-inmanycasesverycomplex-bulkgasflowsinthesourcegeometry. Numericalmethods,inparticularmoderncomputationalfluiddynamics(CFD)solversystems,arethetoolsofchoicetosimulatethegasflowinAPionsources.Rigorousapplicationofthesemethodscouldresultinanimportantstepforwardonthewayfromtrial-and-errortowardsmodeldrivendesignapproachesfornewAPionsourcegeo-metries. Fromourlatestresearchefforts(seeposter070insessionTP04fordetails)weproposethatsuchamodeldrivendesignprocessispossibleandfeasible. Toanalyzethecurrentstateofthetech-nologyandtoproofthatCFDisausefultoolevenforcomplexfluiddynamicalproblems,wesimulatedthegasflowinacommerciallyavailableAPionsource(BrukerMPIS)andvalidatedtheflowsimulationswithappro-priateexperimentalmethods. Inthiscontributionwepresenttheactualflowsimulation,anexperimentalverification,andadetaileddiscussionoftheresults. 德國LaVision PIV/PLIF粒子成像測速場儀