HARMONIC UNIFLOW ENGINE

摘要

A reciprocating-piston uniflow engine includes a harmonic oscillator inlet valve capable of oscillating at a resonant frequency for controlling the flow of working fluid into the engine. In particular, the inlet valve includes an inlet valve head and a spring arranged together as a harmonic oscillator so that the inlet valve head is moveable from an unbiased equilibrium position to a biased closed position occluding an inlet. When released, the inlet valve head undergoes a single oscillation past the equilibrium position to a maximum open position and returns to a biased return position close to the closed position to choke the flow and produce a pressure drop across the inlet valve causing the inlet valve to close. In other embodiments, the harmonic oscillator arrangement of the inlet valve enables the uniflow engine to be reversibly operated as a uniflow compressor.

主权项

1. A harmonic uniflow engine comprising:
a cylinder having a cylinder axis; a piston head reciprocable in the cylinder and together enclosing an expansion chamber, wherein the cylinder has an inlet at an inlet end fluidically connected to the expansion chamber and an outlet at a removed location from the inlet end; an intake header in fluidic communication with the inlet for channeling working fluid from a pressurized fluid source into the expansion chamber; an inlet valve for controlling the flow of working fluid from the intake header into the expansion chamber to effect a power stroke of the engine, said inlet valve comprising an inlet valve head and a resiliently biasing member arranged together as a harmonic oscillator so that the inlet valve head is moveable against an equilibrium restoring force of the resiliently biasing member from an unbiased equilibrium position located in the intake header to a biased closed position occluding the inlet, and so that upon releasing from the closed position the inlet valve head undergoes a single oscillation past the equilibrium position to an oppositely biased maximum open position and returns to a biased return position between the closed and equilibrium positions to choke the flow of working fluid and produce a pressure drop across the inlet valve causing the inlet valve to close, wherein the piston head is reciprocable to a venting position which fluidically connects the expansion chamber to the outlet for controlling the periodic venting of working fluid out from the expansion chamber; and periodic return means operably connected to the piston head to effect a return stroke of the engine after each power stroke.