Abstract: A toilet includes a bowl with a sump and a trapway connecting the sump to an outlet of the toilet. The trapway has a zeta shape and is configured to induce a siphon which provides pressure to suction waste water from the bowl during a flush cycle. A trapway supply conduit is connected to the trapway in a tangential orientation to an upleg region of the trapway. The trapway supply conduit supplies water to the trapway, which follows a contour of the inner surface of the trapway supply conduit and continues in the same direction into the upleg region of the trapway by relying on a fluid flow to follow the curve of a convex surface placed proximate to the flow.

Abstract: A siphonic, gravity-powered toilet is provided that includes a toilet bowl assembly having a toilet bowl. The toilet bowl has a rim channel provided along an upper periphery thereof and a direct-fed jet channel that allows fluid, such as water, to flow from the inlet of the toilet bowl assembly to the direct-fed jet outlet port into the interior of the toilet bowl, in the sump of the bowl. The rim channel includes at least one rim channel outlet port. In this toilet, the cross-sectional areas of the toilet bowl assembly inlet, the inlet port to the rim channel, and the outlet port to the direct-fed jet channel are configured so as to be optimized to provide greatly improved hydraulic function at low flush volumes (no greater than about 6.0 liters per flush). The hydraulic function is improved in terms of bulk removal of waste and cleansing of the bowl.