| 摘要 |
<p>An internal combustion engine piston and combustion chamber are configured to produce controlled reaction of the fuel supplied to the working chamber with prolonged supply of air to the reaction zone over the combustion/expansion part of the engine operating cycle. After an axially stratified charge, with little or no fuel near the piston working face, is established in the working chamber of the engine, part of the air is transferred during the compression of the charge into an air chamber near the working face of the piston which communicates with the working chamber through a restricted gap orifice. The air chamber is configured to resonate at the same frequency as the frequency of the combustion waves in the manner of a Helmholtz resonator, with a specific gap dimension and air chamber volume that is mathematically related to gap area, the speed of sound in the air chamber at the autoignition temperature of the compressed charge in the working chamber, the axial length and radial width of the gap orifice, and the natural Helmholtz resonant frequency of the gas in the air chamber. The resonating gases in the air chamber, moreover, induce closed organ pipe resonance in the working chamber at least one fundamental frequency while the piston is between top and bottom dead center positions. A system for controlling air to fuel ratio is also included to cause the combustion cycle to operate at the maximum attainable "Run Quality Index" (a defined term indicative of practical efficiency) for the specific engine. The piston and working chamber are also configured to produce a dynamic variable compression ratio by preventing total pressure equalization between the working and air chambers above a certain selected engine speed range by causing choked flow to exist between the working and air chambers above said speed range.</p> |
