2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/33906A large class of Type II fluid solutions to Einstein field equations in N-dimensional spherical spacetimes is found, wich includes most of the known solutions. A family of the generalized collapsing Vaidya solutions with homothetic self-similarity, parametrized by a constant $λ$, is studied, and found that when $λ$ $>$ $λ_c(N)$, the collapse always forms black holes, and when $λ$ $<$ $λ_c(N)$, it always forms naked singularities, where $λ_c(N)$ is function of the spacetime dimension N only.16 pages, 2 figures, Revtex, three references addedGeneral Relativity and Quantum Cosmologytext