Noise cancellation by phase-matching communicating ducts of roots-type blower and expander

Abstract

A volumetric assembly includes: a roots-type supercharger device; a roots-type expander device; a first duct extending from the supercharger fluid inlet, the first duct supplying fluid to the roots-type supercharger device; and a second duct extending from the expander fluid outlet, the second duct directing fluid away from the roots-type expander device, wherein the first duct is positioned adjacent to the second duct, and wherein the first duct defines a first aperture and the second duct defines a second aperture, the first and second apertures being generally aligned; and a flexible membrane positioned between the first and second ducts in the first and second apertures, the flexible membrane sealing the first duct from the second duct, and the flexible membrane flexing as fluid flows within the first and second ducts to attenuate noise associated with the fluid flows.

What is claimed is: 
     
         1 . A volumetric assembly, comprising:
 a roots-type supercharger device having at least two supercharger rotors, with each of the rotors having two or more lobes, the roots-type supercharger defining a supercharger fluid inlet and a supercharger fluid outlet;   a roots-type expander device having at least two expander rotors, with each of the rotors having two or more lobes, the roots-type expander defining an expander fluid inlet and an expander fluid outlet;   a first duct extending from the supercharger fluid inlet, the first duct supplying fluid to the roots-type supercharger device; and   a second duct extending from the expander fluid outlet, the second duct directing fluid away from the roots-type expander device, wherein the first duct is positioned adjacent to the second duct, and wherein the first duct defines a first aperture and the second duct defines a second aperture, the first and second apertures being generally aligned; and   a flexible membrane positioned between the first and second ducts in the first and second apertures, the flexible membrane sealing the first duct from the second duct, and the flexible membrane flexing as fluid flows within the first and second ducts to attenuate noise associated with the fluid flows.   
     
     
         2 . The volumetric assembly of  claim 1 , wherein the flexible membrane includes at least one fold to enhance a flexibility of the flexible membrane. 
     
     
         3 . The volumetric assembly of  claim 2 , wherein the assembly is configured to synchronize a first speed of the roots-type supercharger device with a second speed of the roots-type expander device. 
     
     
         4 . The volumetric assembly of  claim 3 , wherein each of the supercharger rotors has four lobes, and each of the expander rotors has two lobes, and wherein second speed is twice that of the first speed. 
     
     
         5 . The volumetric assembly of  claim 1 , wherein the assembly is configured to synchronize a first speed of the roots-type supercharger device with a second speed of the roots-type expander device. 
     
     
         6 . The volumetric assembly of  claim 5 , wherein each of the supercharger rotors has four lobes, and each of the expander rotors has two lobes, and wherein second speed is twice that of the first speed. 
     
     
         7 . The volumetric assembly of  claim 1 , wherein the flexible membrane is made of a polymeric material. 
     
     
         8 . The volumetric assembly of  claim 7 , wherein the flexible membrane includes a plurality of folds to enhance a flexibility of the flexible membrane. 
     
     
         9 . A system, comprising:
 a power source; and   a volumetric assembly, the volumetric assembly including:
 a roots-type supercharger device having at least two supercharger rotors, with each of the rotors having two or more lobes, the roots-type supercharger defining a supercharger fluid inlet and a supercharger fluid outlet, the supercharger fluid outlet being connected to the power source to provide fluid for boosting the power source; 
 a roots-type expander device having at least two expander rotors, with each of the rotors having two or more lobes, the roots-type expander defining an expander fluid inlet and an expander fluid outlet, the expander fluid inlet being coupled to the exhaust of the power source to provide fluid to the expander fluid inlet, and the roots-type expander device applying torque to the power source; 
 a first duct extending from the supercharger fluid inlet, the first duct supplying fluid to the roots-type supercharger device; and 
 a second duct extending from the expander fluid outlet, the second duct directing fluid away from the roots-type expander device, wherein the first duct is positioned adjacent to the second duct, and wherein the first duct defines a first aperture and the second duct defines a second aperture, the first and second apertures being generally aligned; and 
 a flexible membrane positioned between the first and second ducts in the first and second apertures, the flexible membrane sealing the first duct from the second duct, and the flexible membrane flexing as fluid flows within the first and second ducts to attenuate noise associated with the fluid flows. 
   
     
     
         10 . The system of  claim 9 , wherein the flexible membrane includes at least one fold to enhance a flexibility of the flexible membrane. 
     
     
         11 . The system of  claim 10 , wherein the system is configured to synchronize a first speed of the roots-type supercharger device with a second speed of the roots-type expander device. 
     
     
         12 . The system of  claim 11 , wherein each of the supercharger rotors has four lobes, and each of the expander rotors has two lobes, and wherein second speed is twice that of the first speed. 
     
     
         13 . The system of  claim 9 , wherein the system is configured to synchronize a first speed of the roots-type supercharger device with a second speed of the roots-type expander device. 
     
     
         14 . The system of  claim 13 , wherein each of the supercharger rotors has four lobes, and each of the expander rotors has two lobes, and wherein second speed is twice that of the first speed. 
     
     
         15 . The system of  claim 9 , wherein the flexible membrane is made of a polymeric material. 
     
     
         16 . The system of  claim 15 , wherein the flexible membrane includes a plurality of folds to enhance a flexibility of the flexible membrane. 
     
     
         17 . A method of boosting an internal combustion engine and recovering energy from an exhaust of the internal combustion engine, the method comprising:
 providing a roots-type supercharger device to boost the internal combustion engine, the roots-type supercharger having an inlet duct;   providing a roots-type expander device to recover energy directly or indirectly from the exhaust of the internal combustion engine, the roots-type expander device having an outlet duct;   positioning the inlet duct adjacent to the outlet duct; and   configuring a membrane positioned in an aperture between the inlet and outlet ducts to flex as pressure changes within the inlet and outlet ducts.   
     
     
         18 . The method of  claim 17 , further comprising forming at least one fold in the membrane to enhance flexibility of the membrane. 
     
     
         19 . The method of  claim 17 , further comprising synchronizing speeds of the roots-type supercharger device and the roots-type expander device. 
     
     
         20 . The method of  claim 17 , wherein the roots-type expander device recovers energy indirectly from the exhaust through a working fluid in an organic Rankine Cycle.