Exhaust gas diffuser

According to one aspect of the invention, an exhaust gas diffuser (200) includes an outer casing (202) disposed about a center line (205) of the exhaust gas diffuser (200), a hub (204) disposed about the center line (205), and an end portion (214) of the hub (204) comprises a recess (216) configured to cause a flow of exhaust gas toward the center line (205) as the exhaust gas flows in a downstream direction (207).