Patents by Inventor Ross A. Hewitt

Ross A. Hewitt has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7343732
    Abstract: A combustion chamber/supersonic nozzle assembly is cooled by an array of coolant channels in the wall of the assembly with coolant being fed to the assembly at the throat plane between the subsonic (convergent) and supersonic (divergent) sections. A minor portion of the coolant entering at the throat plane is directed to coolant channels in the supersonic section wall, while the remainder is directed to a complex arrangement of channels in the subsonic section wall. The latter arrangement includes an outer layer of wide axially oriented channels for delivery of coolant to, and removal from, an inner layer of smaller, circumferentially oriented channels that are adjacent to the hot gas and carry the bulk of the coolant load. The path of coolant travel through each inner channel is relatively short, lessening the pressure drop through those channels relative to coolant channel arrangements of the prior art.
    Type: Grant
    Filed: March 2, 2004
    Date of Patent: March 18, 2008
    Assignee: Aerojet-General Corporation
    Inventor: Ross A. Hewitt
  • Publication number: 20070029408
    Abstract: A throttling injector is constructed with a swirl chamber, a plurality of tangentially directed liquid fuel inlets and an outlet orifice, the inlets arranged to create a swirling flow in the swirl chamber to leave through the outlet in a stream that is in the shape of a hollow tube or cone. Variations in the number of inlets that are actuated results in variations in the thickness of the wall of liquid in the tube or cone and hence variations in the volumetric flow rate of fuel ejected from the outlet orifice without changing the linear velocity of the fuel in the axial direction through the orifice or the pressure drop across the orifice. The injector thus permits throttling to occur from a high to a low volumetric fuel flow rate without the chugging instability that plagues liquid-fuel-fed combustion chambers of the prior art.
    Type: Application
    Filed: August 2, 2005
    Publication date: February 8, 2007
    Applicant: Aerojet-General Corporation
    Inventor: Ross Hewitt
  • Publication number: 20060144959
    Abstract: A combustion chamber/supersonic nozzle assembly is cooled by an array of coolant channels in the wall of the assembly with coolant being fed to the assembly at the throat plane between the subsonic (convergent) and supersonic (divergent) sections. A minor portion of the coolant entering at the throat plane is directed to coolant channels in the supersonic section wall, while the remainder is directed to a complex arrangement of channels in the subsonic section wall. The latter arrangement includes an outer layer of wide axially oriented channels for delivery of coolant to, and removal from, an inner layer of smaller, circumferentially oriented channels that are adjacent to the hot gas and carry the bulk of the coolant load. The path of coolant travel through each inner channel is relatively short, lessening the pressure drop through those channels relative to coolant channel arrangements of the prior art.
    Type: Application
    Filed: March 2, 2004
    Publication date: July 6, 2006
    Inventor: Ross Hewitt
  • Publication number: 20060021343
    Abstract: The present invention provides heat exchanging elements for use in Stirling engines. According to the present invention, the heat exchanging elements are made from muliple platelets that are stacked and joined together. The use of platelets to make heat exchanging elements permits Stirling engines to run more effiecient because the heat transfer and combustion processes are improved. In one embodiment, multi-stage combustion can be introduced with platlets, along with the flexibility to use different types of fuels. In another embodiment, a single component constructed from platelets can provide the heat transfer rquirements betweeen the combustion gas/working gas, working gas in the regenerator and the working gas/coolant fluid of a Stirling engine. In another embodiment, the platelet heat exchanging element can recieve solar energy to heat the Stirling engine's working gas. Also, this invention provides a heat exchanging method that allows for multiple fuilds to flow in opposing or same direction.
    Type: Application
    Filed: March 2, 2005
    Publication date: February 2, 2006
    Inventors: Joseph Maceda, Randall Peeters, Felix Chen, Ross Hewitt, Jackson Ito, Kenneth Klaas, John Grimes, Svein Hestevik
  • Patent number: 6931848
    Abstract: The present invention provides heat exchanging elements for use in Stirling engines. According to the present invention, the heat exchanging elements are made from muliple platelets that are stacked and joined together. The use of platelets to make heat exchanging elements permits Stirling engines to run more effiecient because the heat transfer and combustion processes are improved. In one embodiment, multi-stage combustion can be introduced with platlets, along with the flexibility to use different types of fuels. In another embodiment, a single component constructed from platelets can provide the heat transfer rquirements betweeen the combustion gas/working gas, working gas in the regenerator and the working gas/coolant fluid of a Stirling engine. In another embodiment, the platelet heat exchanging element can recieve solar energy to heat the Stirling engine's working gas. Also, this invention provides a heat exchanging method that allows for multiple fluids to flow in opposing or same direction.
    Type: Grant
    Filed: January 8, 2003
    Date of Patent: August 23, 2005
    Assignee: Power Play Energy L.L.C.
    Inventors: Joseph P. Maceda, Randall L. Peeters, Felix F. Chen, Ross A. Hewitt, Jackson I. Ito, Kenneth P. Klaas, John L. Grimes, Svein Hestevik
  • Patent number: 6832471
    Abstract: In a supersonic nozzle incorporating injectors and a combustion chamber as part of an expander cycle rocket engine, the oxidizer is injected in two streams. One of the streams, preferably a small fraction of the total, is injected into an upstream or preburner section of the combustion chamber and the other to a downstream or main section of the chamber. The preburner combustion gas is cooled in a substantially uniform manner to a moderate temperature by cooling the bulk of the gas rather than cooling only the gas in a boundary layer adjacent to the chamber wall. The combustion gas produced in the downstream section is hotter, and heat from that gas is drawn through the chamber wall into a jacket. The limited combustion in the preburner permits the use of a cooling element with highly intimate heat exchange construction, extracting a high level of energy from the preburner gas without damage to the cooling element and an overall improvement in the regenerative cooling.
    Type: Grant
    Filed: March 12, 2003
    Date of Patent: December 21, 2004
    Assignee: Aerojet-General Corporation
    Inventor: Ross A. Hewitt
  • Patent number: 6802179
    Abstract: A convergent-divergent rocket nozzle is formed by joining two coaxially aligned conical sections at a throat plane, each diverging outward from the throat plane. Coolant channels formed in the wall of the nozzle are arranged in spirals around the nozzle axis. Preferably, the conical sections are formed from platelet laminates rolled into conical form with a single spiral seam, and at least one of the conical sections is a composite of two or more component conical sections separately formed and then joined in a nested arrangement with the seams not superimposed. A further preferred construction is one in which the convergent end of one conical section is split radially into strips that are then spread apart to serve as bonding surfaces to bond to the other conical section.
    Type: Grant
    Filed: December 2, 2002
    Date of Patent: October 12, 2004
    Assignee: Aerojet-General Corporation
    Inventor: Ross A. Hewitt
  • Patent number: 6799417
    Abstract: Heat is extracted from the combustion gas in a rocket engine combustion chamber by diverting portions of the gas through channels in the nozzle wall. The channels are layered between channels of coolant, which in expander cycle rocket engines is uncombusted fuel, to achieve intimate heat exchange between the combustion gas and the fuel. The combustion gas channels are relatively short, returning combustion gas thus cooled to the chamber interior. By drawing combustion gas from the chamber interior into the chamber wall, the cooling process no longer relies on the combustion gas boundary layer for heat transfer as in the prior art.
    Type: Grant
    Filed: February 5, 2003
    Date of Patent: October 5, 2004
    Assignee: Aerojet-General Corporation
    Inventor: Ross A. Hewitt
  • Publication number: 20040177603
    Abstract: In a supersonic nozzle incorporating injectors and a combustion chamber as part of an expander cycle rocket engine, the oxidizer is injected in two streams. One of the streams, preferably a small fraction of the total, is injected into an upstream or preburner section of the combustion chamber and the other to a downstream or main section of the chamber. The preburner combustion gas is cooled in a substantially uniform manner to a moderate temperature by cooling the bulk of the gas rather than cooling only the gas in a boundary layer adjacent to the chamber wall. The combustion gas produced in the downstream section is hotter, and heat from that gas is drawn through the chamber wall into a jacket. The limited combustion in the preburner permits the use of a cooling element with highly intimate heat exchange construction, extracting a high level of energy from the preburner gas without damage to the cooling element and an overall improvement in the regenerative cooling.
    Type: Application
    Filed: March 12, 2003
    Publication date: September 16, 2004
    Applicant: Aerojet-General Corporation
    Inventor: Ross A. Hewitt
  • Publication number: 20040168428
    Abstract: A convergent-divergent rocket nozzle is formed by joining two coaxially aligned conical sections at a throat plane, each diverging outward from the throat plane. Coolant channels formed in the wall of the nozzle are arranged in spirals around the nozzle axis. Preferably, the conical sections are formed from platelet laminates rolled into conical form with a single spiral seam, and at least one of the conical sections is a composite of two or more component conical sections separately formed and then joined in a nested arrangement with the seams not superimposed. A further preferred construction is one in which the convergent end of one conical section is split radially into strips that are then spread apart to serve as bonding surfaces to bond to the other conical section.
    Type: Application
    Filed: December 2, 2002
    Publication date: September 2, 2004
    Applicant: Aerojet-General Corporation
    Inventor: Ross A. Hewitt
  • Publication number: 20040148923
    Abstract: Heat is extracted from the combustion gas in a rocket engine combustion chamber by diverting portions of the gas through channels in the nozzle wall. The channels are layered between channels of coolant, which in expander cycle rocket engines is uncombusted fuel, to achieve intimate heat exchange between the combustion gas and the fuel. The combustion gas channels are relatively short, returning combustion gas thus cooled to the chamber interior. By drawing combustion gas from the chamber interior into the chamber wall, the cooling process no longer relies on the combustion gas boundary layer for heat transfer as in the prior art.
    Type: Application
    Filed: February 5, 2003
    Publication date: August 5, 2004
    Applicant: Aerojet-General Corporation, a corporation of the state of Ohio
    Inventor: Ross A. Hewitt
  • Publication number: 20030163990
    Abstract: The present invention provides heat exchanging elements for use in Stirling engines. According to the present invention, the heat exchanging elements are made from muliple platelets that are stacked and joined together. The use of platelets to make heat exchanging elements permits Stirling engines to run more effiecient because the heat transfer and combustion processes are improved. In one embodiment, multi-stage combustion can be introduced with platlets, along with the flexibility to use different types of fuels. In another embodiment, a single component constructed from platelets can provide the heat transfer rquirements betweeen the combustion gas/working gas, working gas in the regenerator and the working gas/coolant fluid of a Stirling engine. In another embodiment, the platelet heat exchanging element can recieve solar energy to heat the Stirling engine's working gas. Also, this invention provides a heat exchanging method that allows for multiple fluids to flow in opposing or same direction.
    Type: Application
    Filed: January 8, 2003
    Publication date: September 4, 2003
    Inventors: Joseph P. Maceda, Randall L. Peeters, Felix F. Chen, Ross A. Hewitt, Jackson I. Ito, Kenneth P. Klaas, John L. Grimes, Svein Hestevik
  • Patent number: 6513326
    Abstract: The present invention provides heat exchanging elements for use in Stirling engines. According to the present invention, the heat exchanging elements are made from muliple platelets that are stacked and joined together. The use of platelets to make heat exchanging elements permits Stirling engines to run more effiecient because the heat transfer and combustion processes are improved. In one embodiment, multi-stage combustion can be introduced with platlets, along with the flexibility to use different types of fuels. In another embodiment, a single component constructed from platelets can provide the heat transfer requirements between the combustion gas/working gas, working gas in the regenerator and the working gas/coolant fluid of a Stirling engine. In another embodiment, the platelet heat exchanging element can recieve solar energy to heat the Stirling engine's working gas. Also, this invention provides a heat exchanging method that allows for multiple fluids to flow in opposing or same direction.
    Type: Grant
    Filed: March 4, 2002
    Date of Patent: February 4, 2003
    Inventors: Joseph P. Maceda, Randall L. Peeters, Felix F. Chen, Ross A. Hewitt, Jackson I. Ito, Kenneth P. Klaas, John L. Grimes, Svein Hestevik