Thecurrent contributionemphasizesentropygenerationdue tobio-convection(Cu?TiO2)/H2O-modifiednano-liquid flowthroughtheL-shapedcavitywiththreeobstaclesconsideringtheaspectofgyrotacticmicroorganisms.Theactive sectionsofthebottomhorizontalandleftverticalwallsarepreservedcoolwhiletheotherportionsoftheporouscavityare insulated.ThefinitemethodisadoptedtosimulatethedimensionlessPDEsofthemodel.Theresultsdemonstratedhowthe influenceofthebio-convectionfactorsincreasesthedensityofmotilemicroorganisms.Ithasbeennotedthatthelocaland averageheat transmissionrateshaveincreasedwithhighervaluesof thelengthofcoldparts(heatsink), theverticaland horizontalwalls’ crest lengths, andnanoparticlevolume fraction. Largevalues of theRayleighnumber diminish the thermalperformancerate.Entropygeneration,localNusseltandSherwoodnumbers,anddensityofmotilemicroorganisms arealsoargued.