Unsteadymotionofaverticallyfallingnon-sphericalparticlehasattractedconsiderableattentionduetoitsfrequentapplicationsinnatureandindustry.Aseriesofsemi-analyticalmethodshavebeenusedtoraisetheresults’accuracyaswellaswideningtheregionofconvergence.Thecurrentstudypursuedanewanalyticalsolutionfortheunsteadymotionofarigidnon-sphericalparticleinaquiescentNewtonianfluid,basedontheOptimalHomotopyAnalysisMethod.Withaviewtowardsobtainingthehighestlevelofaccuracyandensuringtheconvergenceoftheanalyticalresults,theaveragedresidualerrorswereobtainedandminimized.Inadditiontoflexibility,itwasalsoproventhattheproposedmethodcanleadtocompletelyreliableandpreciselyaccurateresults.Basedontheseriessolution,theeffectsofphysicalparametersontheterminalsettlingvelocity(i.e.thegreatestvelocitythatafallingbodymayreach)andtheaccelerationtime(i.e.thetimethataparticlereachesthesettlingvelocity)areinvestigated.
