Abstract: Thermal energy storage systems and methods are provided including a bed, a blend of aggregates packed in the bed, and a high-density heat transfer fluid flowing through the blend of aggregates. The blend of aggregates includes rock materials and may also include non-rock materials. The heat transfer fluid flows through the blend of aggregates such that heat is transferred between the heat transfer fluid and the blend of aggregates. The porosity of the aggregates increases heat transfer and the high density of the heat transfer fluid reduces the pressure gradient of the heat transfer fluid. In exemplary embodiments, the heat transfer fluid is a liquid comprised of carbon-based molecules. Methods of safely storing and releasing energy are provided in which axial thermal conductivity of the bed is minimized and inadvertent pressure release failures are mitigated.

Abstract: Implementations described herein provide a high efficiency steam cycle that includes a steam turbine cycle coupled to output of a high performance steam piston topping (HPSPT) cycle. The HPSPT cycle includes a piston-cylinder assembly that extracts work from an expanding fluid volume and operates in a thermal regime outside of thermal operational limits of a steam turbine. The steam turbine cycle utilizes heat, transferred at the output of the HPSPT cycle, to generate turbine work.

Abstract: The presently disclosed technology relates to carbon-on-carbon (C/C) manufacturing techniques and the resulting C/C products. One aspect of the manufacturing techniques disclosed herein utilizes two distinct curing operations that occur at different times and/or using different temperatures. The resulting C/C products are substantially non-porous, even though the curing operation(s) substantially gasify a liquid carbon-entrained filler material that saturates a carbon fabric that makes up the C/C products.

Abstract: A high efficiency energy conversion system disclosed herein incorporates a piston assembly including a sealed cylinder for storing a working fluid and an energy conversion element attached to the piston assembly. A kinematic mechanism such as a cam lobe or a scotch yoke may be used as the energy conversion element. In one implementation, the kinematic mechanism may be configured to provide rapid piston expansion in a manner so as not to allow the expanding working fluid inside the piston to achieve thermodynamic equilibrium. In an alternate implementation, the kinematic mechanism is further adapted to generate a compression stroke in a manner to provide the working fluid inside the piston to achieve thermodynamic equilibrium conditions throughout the compression stroke.

Abstract: A throttleable exhaust venturi is described herein that generates strong suction pressures at an exhaust outlet by accelerating an incoming ambient fluid stream with the aid of a venturi to high gas velocities and injecting a combustion exhaust stream into the ambient fluid stream at an effective venturi throat. A mixing element downstream of the venturi throat ensures that the mixed fluid stream recovers from a negative static pressure up to local atmospheric pressure. A physical and the effective throat of the venturi are designed to promote mixing and stabilize the ambient fluid flow to ensure that high velocity is achieved and the effective venturi is operable over a variety of combustion exhaust stream mass flow rates.

Abstract: The presently disclosed technology relates to carbon-on-carbon (C/C) manufacturing techniques and the resulting C/C products. One aspect of the manufacturing techniques disclosed herein utilizes two distinct curing operations that occur at different times and/or using different temperatures. The resulting C/C products are substantially non-porous, even though the curing operation(s) substantially gasify a liquid carbon-entrained filler material that saturates a carbon fabric that makes up the C/C products.

Abstract: A cylinder has an insulating gas boundary layer (IGBL) across the cylinder wall inner surface, the IGBL formed by injection of an insulator fluid into the combustion chamber of the cylinder. In one implementation, a pressure differential is engineered between the top region of the cylinder and the bottom region of the cylinder. In yet another implementation, the insulator injection pressure is temporally modified in synchronicity with the piston cycle and/or in accordance with other temporal factors to provide appropriate IGBL coverage.

Abstract: Implementations described herein provide a high efficiency steam cycle that includes a steam turbine cycle coupled to output of a high performance steam piston topping (HPSPT) cycle. The HPSPT cycle includes a piston-cylinder assembly that extracts work from an expanding fluid volume and operates in a thermal regime outside of thermal operational limits of a steam turbine. The steam turbine cycle utilizes heat, transferred at the output of the HPSPT cycle, to generate turbine work.

Abstract: An apparatus and system disclosed herein provides detonation wave arrestor including a detonation wave deflector and a burst element. The detonation wave arrestor disclosed herein attenuates and defects the propagation of a detonation wave characterized by a supersonic flame front propagation. The detonation wave arrestor provides deflection of detonation wave towards the burst element. The rupture of the burst element provides venting of hot gases remaining from the detonation, thus providing separation and attenuation of combusted gas residuals. The detonation wave arrestor disclosed herein may be used in a combustible fuel delivery system.

Abstract: A clustered, fixed cant, throttleable rocket assembly is used to propel and a steer a vessel in terrestrial or extraterrestrial applications. The fixed cant of each of at least three individual rockets in the cluster provides the steering input to the overall assembly. More specifically, by changing the propellant flow rate to the individual rocket engines relative to one another, the overall thrust vector of the rocket assembly may be selected to provide a desired steering input to the vessel. A measured vessel orientation may be compared with a desired vessel orientation to determine what steering input is required to achieve the desired vessel orientation.

Abstract: Propellants flow through specialized mechanical hardware that is designed for effective and safe ignition and sustained combustion of the propellants. By integrating a micro-fluidic porous media element between a propellant feed source and the combustion chamber, an effective and reliable propellant injector head may be implemented that is capable of withstanding transient combustion and detonation waves that commonly occur during an ignition event. The micro-fluidic porous media element is of specified porosity or porosity gradient selected to be appropriate for a given propellant. Additionally the propellant injector head design integrates a spark ignition mechanism that withstands extremely hot running conditions without noticeable spark mechanism degradation.

Abstract: A thermal variation source (e.g., a heater or a heat sink) is used to induce a temperature gradient across an interior surface of a storage tank. The storage tank stores a working fluid (e.g., a fuel, and oxidizer, or a monopropellant) that may have pockets of gaseous-phase working fluid interspersed within liquid-phase working fluid, or vice versa. In the absence of gravity or other significant forces on the working fluid, the temperature gradient is sufficient to cause phase-separation of the working fluid and allow either the liquid-phase or the gaseous-phase working fluid to be withdrawn from the storage tank, as desired.

Abstract: Propellants flow through specialized mechanical hardware that is designed for effective and safe ignition and sustained combustion of the propellants. By integrating a micro-fluidic porous media element between a propellant feed source and the combustion chamber, an effective and reliable propellant injector head may be implemented that is capable of withstanding transient combustion and detonation waves that commonly occur during an ignition event. The micro-fluidic porous media element is of specified porosity or porosity gradient selected to be appropriate for a given propellant. Additionally the propellant injector head design integrates a spark ignition mechanism that withstands extremely hot running conditions without noticeable spark mechanism degradation.

Abstract: Propellants flow through specialized mechanical hardware that is designed for effective and safe ignition and sustained combustion of the propellants. By integrating a micro-fluidic porous media element between a propellant feed source and the combustion chamber, an effective and reliable propellant injector head may be implemented that is capable of withstanding transient combustion and detonation waves that commonly occur during an ignition event. The micro-fluidic porous media element is of specified porosity or porosity gradient selected to be appropriate for a given propellant. Additionally the propellant injector head design integrates a spark ignition mechanism that withstands extremely hot running conditions without noticeable spark mechanism degradation.

Abstract: A throttleable exhaust venturi is described herein that generates strong suction pressures at an exhaust outlet by accelerating an incoming ambient fluid stream with the aid of a venturi to high gas velocities and injecting a combustion exhaust stream into the ambient fluid stream at an effective venturi throat. A mixing element downstream of the venturi throat ensures that the mixed fluid stream recovers from a negative static pressure up to local atmospheric pressure. A physical and the effective throat of the venturi are designed to promote mixing and stabilize the ambient fluid flow to ensure that high velocity is achieved and the effective venturi is operable over a variety of combustion exhaust stream mass flow rates.

Abstract: A throttleable exhaust venturi is described herein that generates strong suction pressures at an exhaust outlet by accelerating an incoming ambient fluid stream with the aid of a venturi to high gas velocities and injecting a combustion exhaust stream into the ambient fluid stream at an effective venturi throat. A mixing element downstream of the venturi throat ensures that the mixed fluid stream recovers from a negative static pressure up to local atmospheric pressure. A physical and the effective throat of the venturi are designed to promote mixing and stabilize the ambient fluid flow to ensure that high velocity is achieved and the effective venturi is operable over a variety of combustion exhaust stream mass flow rates.

Abstract: Propellants flow through specialized mechanical hardware that is designed for effective and safe ignition and sustained combustion of the propellants. By integrating a micro-fluidic porous media element between a propellant feed source and the combustion chamber, an effective and reliable propellant injector head may be implemented that is capable of withstanding transient combustion and detonation waves that commonly occur during an ignition event. The micro-fluidic porous media element is of specified porosity or porosity gradient selected to be appropriate for a given propellant. Additionally the propellant injector head design integrates a spark ignition mechanism that withstands extremely hot running conditions without noticeable spark mechanism degradation.

Abstract: A high efficiency energy conversion system disclosed herein incorporates a piston assembly including a sealed cylinder for storing a working fluid and an energy conversion element attached to the piston assembly. A kinematic mechanism such as a cam lobe or a scotch yoke may be used as the energy conversion element. In one implementation, the kinematic mechanism may be configured to provide rapid piston expansion in a manner so as not to allow the expanding working fluid inside the piston to achieve thermodynamic equilibrium. In an alternate implementation, the kinematic mechanism is further adapted to generate a compression stroke in a manner to provide the working fluid inside the piston to achieve thermodynamic equilibrium conditions throughout the compression stroke.

Abstract: An alternative or supplement to combustion within an engine is decomposition of nitrous oxide into two parts nitrogen, one part oxygen. This decomposition releases thermal energy that may be captured and converted to useful work. Traditional combustion engines are limited to oxidizer/fuel ratio ratios near the proportional mixture of fuel and oxidizer that achieves complete combustion of the fuel. The presently disclosed technology increases the oxidizer/fuel ratio above that of all traditional combustion engines and still achieves useable power output primarily through decomposition of nitrous oxide. Decomposition of nitrous oxide into nitrogen and oxygen in an engine outputs two parts nitrogen and one part oxygen, which is roughly equivalent to oxygen rich atmospheric air. Output of carbon dioxide and other undesirable chemical compounds is avoided when compared to combustion of a carbon-hydrogen fuel and an oxidizer containing oxygen.

Abstract: A supersonic combustor as a component of a rocket nozzle offers improved utilization of available chemical energy that may be released from combustion gasses flowing through the rocket nozzle. A subsonic combustor sub-sonically accelerates an exothermically reacting combustion gas up to a nozzle throat. The supersonic combustor expands and super-sonically accelerates the exothermically reacting combustion gas beyond the nozzle throat. The dimensions of the supersonic combustor may be selected such that the supersonic combustor achieves a slow rate of cooling of the combustion gasses without creating shockwaves within the supersonic combustor. A supersonic discharge expands and super-sonically accelerates the now substantially non-reacting combustion gas through a supersonic discharge of the rocket nozzle. The momentum of the combustion gas leaving the supersonic discharge propels the rocket nozzle in the opposite direction due to the principle of conservation of momentum.