Wave interference silencing system

Claim 2

A silencing system for attenuating exhaust gas sound waves from an internal combustion engine, comprising: a plurality of serially connected attenuating members having low acoustical impedance volumes fluidly coupled thereto; and a pair of discrete flow paths in each of said attenuating members that are individually temperature and flow compensated for the sound waves transiting therewithin so as to establish actual sound propagational velocities for the latter that will cause destructive interference in said volume at the exit end of the transited attenuating member thereby suppressing objectionable noises at predetermined frequencies, each attenuating member further including means for compensating the mass flow through the separate flow paths to equalize vibrational energy arriving at said volumes and thereby minimize vibrational pressures at the entrance end of a succeeding attenuating member.

Claim 3

A wave interference exhaust system for attenuating sound waves in the frequency spectrum produced in the exhaust gases of an internal combustion engine, comprising: an exhaust line including a plurality of attenuating sections acoustically coupled in series; conduit means of a low acoustical impedance fluidly succeeding each attenuating section; and a pair of alternate gas flow paths in each attenuating section which handle substantially equal vibrational energy and mass gas flow, and produce destructive interference in the succeeding conduit means, the ratio of the flow path lengths for the individual sections being effective to attenuate a predetermined frequency band in said spectrum, and with the remaining sections, cumulatively reduce objectionable vibrational energy to an acceptable level.

Claim 4

A wave interference exhaust system for attenuating sound waves in the frequency spectrum produced in the exhaust gases of an internal combustion engine, comprising: an exhaust line including a plurality of attenuating sections acoustically coupled in series; conduit means of a low acoustical impedance fluidly succeeding each attenuating section; and a pair of alternate gas flow paths in each attenuating section which handle substantially equal vibrational energy and mass gas flow, and produce destructive interference in the succeeding conduit means, the ratio of the flow path lengths for the individual sections being effective to attenuate a predetermined frequency band in said spectrum, and with the remaining sections, cumulatively reduce objectionable vibrational energy to an acceptable level.

Claim 5

sizing the flow paths to handle equal vibrational energies;

Claim 6

sizing the flow paths to handle equal vibrational energies;

Claim 7

dividing the flow paths into discrete sections;

Claim 8

dividing the flow paths into discrete sections;

Claim 9

A wave interference silencing system for predictably attenuating sound waves at select frequency bands in the noise spectrum of the exhaust gases from an internal combustion engine, comprising: a plurality of attenuating sections acoustically coupled in series; acoustical equalizing conduits fluidly succeeding each attenuating sections; a pair of discrete flow paths in each attenuating section, said flow paths having differing acoustical lengths and being temperature and flow compensated to establish actual sound propagational velocities so that pressure waves transiting therewithin are in appreciable phase opposition at the exit of the transited paths so as to destructively interfere within said equalizing conduits, said sections being standardized in sectional design and being of individual lengths which will provide predictable attenuation responses at said select frequency bands whereby subsequent consideration of a single parameter permits a system design of predictable attenuating response.

Claim 10

A wave interference silencing system for predictably attenuating sound waves at select frequency bands in the noise spectrum of the exhaust gases from an internal combustion engine, comprising: a plurality of attenuating sections acoustically coupled in series; acoustical equalizing conduits fluidly succeeding each attenuating sections; a pair of discrete flow paths in each attenuating section, said flow paths having differing acoustical lengths and being temperature and flow compensated to establish actual sound propagational velocities so that pressure waves transiting therewithin are in appreciable phase opposition at the exit of the transited paths so as to destructively interfere within said equalizing conduits, said sections being standardized in sectional design and being of individual lengths which will provide predictable attenuation responses at said select frequency bands whereby subsequent consideration of a single parameter permits a system design of predictable attenuating response.

Claim 13

establishing a length ratio between the flow paths iN the individual sections which is flow and temperature compensated to place the sound waves in phase opposition;

Claim 14

establishing a length ratio between the flow paths iN the individual sections which is flow and temperature compensated to place the sound waves in phase opposition;

Claim 15

selecting a discriminate length for the compensated sections to produce predictable attenuation responses at a select frequency band of the noise spectrum of the exhaust gases; and

Claim 16

selecting a discriminate length for the compensated sections to produce predictable attenuation responses at a select frequency band of the noise spectrum of the exhaust gases; and

Claim 17

combining the flow paths at low impedance volumes succeeding each section to cause the pressure waves transiting the individual flow paths to destructively interfere and cumulatively produce an attenuated ambient acoustical pressure for the frequency noise spectrum of the engine.

Claim 18

combining the flow paths at low impedance volumes succeeding each section to cause the pressure waves transiting the individual flow paths to destructively interfere and cumulatively produce an attenuated ambient acoustical pressure for the frequency noise spectrum of the engine.