Internal combustion engine using dynamic resonating air chamber
AssigneeSonex Research, Inc.
InventorsAndrew A. Pouring, Daniel G. Ferer
Life of this patent
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Abstract
An internal combustion engine includes a moving piston within a combustion chamber that is temporarily divided into two zones when the piston is at and near its minumum volume position. Fuel is confined to a first zone where the fuel is ignited to generate combustion wave energy that drives gas within the second zone in Helmholtz resonance through a restricted passageway. Air from the second zone is periodically expanded into the first zone through the passageway to improve the combustion process in the first zone before the piston moves substantially away from its minimum volume position.
Claims45
In an internal combustion engine including a movable piston in a variable volume combustion chamber having an effective diametrical dimension D and defined in part by fixed walls and in part by a working force of the piston, intake and exhaust valve means for controlling flow of charge and exhaust products to and from the combustion chamber;
- and fuel and air supply means for preparing and supplying a charge to the combustion chamber;
- the improvement comprising, said combustion chamber is configured such that, at and closely proximate the minimum combustion chamber volume position of the piston, the combustion chamber is effectively temporarily divided into an ignition chamber having a volume V.sub.A and a resonating chamber having a volume V.sub.B with a temporary restricted connecting passageway means between said chambers, said temporary passageway being effectively removed as the piston moves away from its minimum volume position, said passageway means having a length L measured along a line connecting V.sub.A and V.sub.B, an average transverse dimension g measured across its width approximately perpendicular to the length L, a cross-sectional area S at its transverse dimension g, and a volume V.sub.P of S.times.L;
- the ignition of each charge producing periodic combustion wave energy of frequency F.sub.A which travels near the speed of sound C.sub.A within said ignition chamber at approximately the autoignition temperature of the charge in said ignition chamber;
- said passageway dimensions g and L being arranged to quench flame propagation between V.sub.A and V.sub.B during substantially the time the piston is at and closely proximate its minimum volume position;
- said resonating chamber and passageway means arranged to constitute a Helmholtz resonator having a resonant frequency F.sub.B at the temperature extant in V.sub.B while combustion is occurring in V.sub.A, with F.sub.A and F.sub.B being approximately equal to each other;
- the maximum linear dimensions of V.sub.B and V.sub.P being generally less than 1/4 wavelength of F.sub.B at the temperature extant in V.sub.B during combustion in V.sub.A ;
- said intake and exhaust valve means and said fuel and air supply means being arranged to establish a charge distribution in the combustion chamber such that, at the moment of ignition thereof, substantially all the fuel of the charge is in the ignition chamber and substantially only air with an insufficient amount of fuel to support work-producing combustion is in the resonating chamber;
- and the relationships between S, V.sub.B and L being defined as:
- ##EQU8## where (using metric units):
- k is a Helmholtz correction factor numerically between 0.6 and 0.85;
- L has a minimum dimension not exceeding the minimum dimension of g;
- g is nominally initially determined by assuming that the transverse dimension g of the passageway is uniform along its width and is related to D in accordance with the formula:
- g=0.1072D+0.1143
- within the tolerance range of +0.050 cm. and -0.25 cm.;
- and
- F.sub.B equals K/D Hz, where K has a numerical value between 43,000 and 51,000.
A process for carrying out combustion of an air and fuel charge in an internal combustion engine using a movable piston to vary an initially undivided combustion chamber volume defined at least in part by a working face of the piston and in which the charge is placed and combusted, the working face of the piston compressing at least the air portion of the charge in the undivided combustion chamber volume to a minimum volume at or near which ignition of the charge is initiated, comprising:
- (1) temporarily dividing the undivided combustion chamber volume above the working face of the piston into first and second regions at or near the minimum volume position of the piston, with said regions connected by a restricted passageway means across which combustion of charge is inhibited;
- (2) confining virtually all of the fuel of the charge in the first region and igniting same in said region to generate periodic combustion wave energy;
- (3) arranging the passageway means and second region to behave as a Helmholtz resonator having a resonant frequency at the frequency of the periodic combustion wave energy of the prevailing temperature of combustion in the first region and driving compressed heated air in the said second region in Helmholtz resonance by the periodic combustion wave energy to cause periodic outflow of air from the second region into the first region through the passageway means while the piston is at and near its minimum volume position;
- (4) expanding the combustion chamber by movement of the piston away from its minimum volume position to reestablish an undivided combustion chamber volume after the charge is ignited and after the second chamber has been driven in Helholtz resonance by the periodic combustion wave energy.
Dependencies are inferred from the claim text.