Purpose– Thispaperaimstoexplore,through a numerical study, buoyant convective phenomena in a porous cavity containing a hybrid nanofluid, taking into account the local thermal nonequilibrium (LTNE) approach. The cavity contains a solid block in the shape of a cross (þ). It will be helpful to develop and optimize the thermal systems with intricate geometries under LTNEconditions for a variety of applications