In　the　present　work,　the　entropy　production　of　Al2O3-water　nanofluid　in　an　oblique　cavity　enclosure　is　examined.　The　side　edges　of　the　enclosure　are　at　lower　temperature　and　the　top　and　down　ones　are　insulated.　Two　thick　conductive　walls　are　placed　on　the　low　temperature　edges.　Furthermore,　the　center　of　the　enclosure　is　equipped　with　a　constant　high　temperature　heat　source.　The　enclosure　is　exposed　to　an　inclined　magnetic　field.　The　governing　nonlinear　partial　differential　equations　are　continuity,　Navier–Stokes　and　energy　equations.　These　equations　are　solved　using　an　open-source　CFD　software　package　(OpenFOAM).　The　influence　of　effective　parameters　includes　Ra　number,　Hartman　number,　the　angles　of　magnetic　field　and　enclosure,　nanoadditives　concentration,　and　aspect　ratio　on　the　entropy　production　and　the　Bejan　(Be)　number　are　investigated.　The　results　show　that　the　minimum　entropy　production　happened　at　low　power　magnetic　fields.　With　the　increase　of　the　slope　of　the　cavity,　the　entropy　production　rises.　The　addition　of　nanoadditives　leads　to　an　intensification　in　the　entropy　production　and　a　reduction　in　the　Be　number.　©　2019　Elsevier　Ltd