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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Design and Testing of a Water-Cooled Rotating Detonation Combustor at Elevated Operating Pressures - Abstract

This is an extended abstract being submitted for consideration that briefly describes the material that will be included in the final paper. This study will detail the design and testing of a water-cooled Rotating Detonation Combustor (RDC) that permits operation for extended periods of time ensuring that the device has reach a stable operating temperature. Extended run times also provides an opportunity to consider transient behaviors that occur as a result of altering the operating conditions such as equivalence ratio. The experimental setup is also unique in that it consists of a ducted exhaust with a downstream high-temperature valve that can control the pre-combustion pressure in the RDC independent of the combustor annulus and exit geometry. This paper will examine the results from the extended operation of the water-cooled RDC over a range of both transient and steady state equivalence ratios (0.5 - 1.0), pre-combustion operating pressures (0 - 207 kPa), mass flow rates (0.42 – 0.5 kg/sec) and air inlet throat area to combustor channel area ratios (0.09 – 0.32). All tests were performed while operating on hydrogen in air at a nominal air inlet temperature of 340 – 350 K. Limited data obtained at an elevated inlet air temperature of 480 K will also be discussed. Results suggest that under certain conditions the operating mode of the detonation wave can vary as it approaches a stable operating temperature. For the RDC tested, a stable operating temperature is not achieved until approximately 8-10 seconds of run time.

Ferguson, Donald↗
DOE OSTI2021

Direct heat exchanger for molten chloride fast reactor

A molten chloride fast reactor (MCFR) includes a plurality of reflectors defining a central core having a core geometric center. A flow channel fluidically connected to the central core. The flow channel includes an outlet flow channel downstream of the central core and an inlet flow channel upstream from the central core. A primary heat exchanger (PHX) disposed outside the central core and between the outlet flow channel and the inlet flow channel. The MCFR also includes a decay heat heat exchanger (DHHX). At least a portion of the DHHX is disposed above the core geometric center, and a fuel salt is configured to circulate at least partially through the outlet flow channel, the DHHX, the PHX, the inlet flow channel, and the central core.

Abbott, Ryan↗
DOE OSTI2021

Single stage clarifier and mixing assembly

A single stage clarifier mixing assembly includes a housing having a circular sidewall and a center axis, a mixing section in the housing, a clarifier section overlying and axially aligned with the mixing section along the center axis within the housing, an inlet delivering an inlet stream to the mixing section and an agitator. The agitator is adapted for mixing the inlet stream in the mixing chamber.

Werner, Joshua Michael↗
DOE OSTI2022

Parallelized multiple nozzle system and method to produce layered droplets and fibers for microencapsulation

The present disclosure relates to a nozzle system for use in a microfluidic production application for producing at least one of particles, capsules or fibers. The system has a main body portion having a compressed fluid inlet and a core fluid inlet, and a plurality of parallel arranged core fluid nozzles that receive the core fluid and create a plurality of core fluid streams. At least one compressed fluid inlet associated with the main body channels compressed fluid to areas adjacent ends of the core fluid nozzles. An apertured plate having a plurality of apertures is arranged near the ends of the core fluid nozzles, with each aperture being uniquely associated with a single one of the core fluid nozzles. The compressed fluid acts on the core fluid streams exiting the core fluid nozzles to help create, with the apertures, at least one of core fluid droplets or core fluid fibers from the core fluid streams.

Ye, Congwang↗
DOE OSTI2022

Radial Compressors with Advanced Secondary Flow Paths for Extended Operating Range

Adequate range is a critical criterion in determining the proper compressor for a given application. In industries centering on turbochargers, range is often the dominant concern. Many times, significant sacrifices in performance are made at the design point in order to obtain enough range of the machine for the duty required. Active controls, the most common being inlet guide vanes (IGVs), can provide sufficient range extension while generating minimal degradation of performance at the design point. Such devices, however, add significant cost and complexity to the machine as they require an active control mechanism. Other devices, such as recirculating casing treatment (RCT), have the advantage of both cost and simplicity by virtue of their passive nature. They’ve seen widespread adoption in the turbocharger industry, though they are generally less effective than IGVs in extending range. A novel approach to extend compressor range through a passive method is proposed here. The method takes some inspiration from classical RCT applications in that it prompts recirculation at low flow rates and corresponding higher back pressures. This recirculation then occupies a portion of the primary cross-sectional passage area and confines the rest of the non-recirculating flow to a smaller area. This restriction forces a higher meridional velocity and a more favorable incidence angle at the impeller blade leading edge. The recirculation is accomplished by laying out an expanded secondary flow path at the rear of the impeller leading back to the inlet hub region. Vanes on the rear of the impeller disk provide just enough pressure rise to counter the induced pressure from the primary flow at the design point. This yields very low mass flow in the secondary path, a condition known as “shutoff” in the pump industry. At lower primary flow levels, and higher back pressures, the secondary flow is induced back to the impeller inlet setting up the recirculation region and pinching the primary flow. Various vane configurations and layouts in the secondary region are explained, and advantages and disadvantages of each are covered. The range extensions made possible by this method and the corresponding impact on performance is discussed.

compressors, extended operating range↗
DOE OSTI2022

Hierarchical triply periodic minimal surface structures as heat exchangers and reactors

The present disclosure relates to a transport mechanism apparatus for transporting at least one of a gas or a fluid. The transport mechanism may have an inlet, an outlet and a triply periodic minimal surface (TPMS) structure. The TPMS structure is formed in a layer-by-layer three dimensional (3D) printing operation to include cells propagating in three dimensions, where the cells include wall portions having openings, and where the cells form a plurality of flow paths throughout the transport mechanism from the inlet to the outlet, and where the cells form the inlet and the outlet.

Roy, Pratanu↗
DOE OSTI2022

Turbocharger system with turbine bypass circuit to reduce emissions during engine cold start

An engine system includes an engine having first and second exhaust manifolds each having outlet ports and a bypass runner. A first turbocharger is in fluid communication with the outlet port of the first manifold, and a second turbocharger in fluid communication with the outlet port of the second manifold. An exhaust aftertreatment device is in fluid communication with the first and second turbochargers. A turbocharger bypass circuit includes a valve assembly having an inlet side connected in fluid communication with the bypass runners of the first and second manifolds, an outlet side in fluid communication with the aftertreatment device, and a valve having an open position in which the inlet and outlet sides are in fluid communication and a closed position in which the inlet and outlet sides are not in fluid communication.

Plagens, Keith Michael↗
DOE OSTI2021

PERFORMANCE CHARACTERIZATION OF THE DIRECT CONTACT MEMBRANE DISTILLATION MODULE OPERATED WITH HIGHLY CONCENTRATED SOLUTION

The experimental study was conducted to characterize the performance of the flat sheet Direct Contact Membrane Distillation. The length degradation was studied in a short and long module with and without spacers. The experimental study is validated using the predicted flux for a wide range of operating conditions using deionized water. Three different membranes are used in the parametric study for feed Reynolds number varied between 500 and 2000, and inlet feed temperature varied between 45°C and 80°C. PTFE membrane was shown to be more effective than the PVDF due to its higher permeability coefficient and higher hydrophobicity. Fouling study was conducted on the selected PTFE membrane with various feed Reynolds numbers between 500 and 2000 and feed inlet temperature between 50°C and 80°C. Membranes used in the fouling study were characterized using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) for the morphology and chemical composition of the fouling layer. 36 hours of operation with 10 wt% NaCl (100,000 ppm) at feed inlet temperatures 80°C and 60°C and fixed Reynolds 2000 demonstrated a drop in flux by 31% and 27%, respectively. Low flow rate and high temperature are favorable conditions for fouling formation and reduced permeate flux for highly concentrated solutions. The spacers improved the flux by 30.8% and 27.6% at the operating Reynolds numbers 2000 the short and long channel modules. This study helps to design and optimize DCMD modules for industrial-size desalination and water treatment applications.

Kim, Deliya↗
DOE OSTI2022

Inadvertent actuation block valve for a small modular nuclear reactor

An inadvertent actuation block valve includes inlet and outlet orifices being in selective fluid communication via a chamber. A disc is disposed within the chamber and a bellows is configured to contract at a predetermined pressure differential between reactor fluid entering a reference pressure orifice and control fluid entering the inlet orifice. When the bellows contracts, the disc engages the outlet orifice and isolates fluid communication between the inlet and outlet orifices. The inadvertent actuation block valve prevents inadvertent opening of an emergency core cooling valve when a reactor is at operating pressure that is above the predetermined set pressure range. The inadvertent actuation block valve permits the emergency cooling valves to open and to remain open when reactor pressure is below the predetermined set pressure range. The inadvertent actuation block valve does not impede long term emergency cooling that occurs when the reactor is at low pressure.

O'Brien, Hugh S.↗
DOE OSTI2023

Single stage clarifier and mixing assembly

A single stage clarifier and mixing assembly includes a housing, a mixing section within the housing and a clarifier section within the housing. The mixing section includes a mixing chamber having (a) an inlet, adapted for delivering an inlet stream to the mixing chamber, at an upper end, and (b) a mixing section outlet at a lower end. The clarifier section extends concentrically around the mixing section. The single stage clarifier and mixing assembly also includes an agitator adapted for mixing the inlet stream in the mixing chamber.

Werner, Joshua Michael↗
DOE OSTI2023

Gas sensor system

A gas sensing tube includes an outer surface, and an inner surface defining a passage. A sensor node is arranged along the sensing tube. The sensor node includes an inlet fluidically connected to the passage, an outlet fluidically connected to the passage, and an interior chamber arranged between the inlet and the outlet. A sensor cable extends along the sensing tube. The sensor cable includes a first conduit having a first connector coupled to the sensor node at the inlet and a second conduit having a second connector connected to the sensor node at the outlet. The sensor cable has a first conductor extending through the first conduit and being coupled to the first connector and a second conductor extending through the second conduit and being coupled to the second connector.

Challener, William Albert↗
DOE OSTI2023

Apparatus for a laser welding system

A laser welding system for welding a component and reducing defects in the weld by ensuring uniform, laminar gas flow over a process area of the system. The laser welding system comprises a laser for welding the component, a platform for supporting the component, an enclosure surrounding the platform, a first actuatable barrier, a second actuatable barrier, an actuator, and a controller. The enclosure includes a plurality of walls, one of the walls having an inlet and another wall having an outlet. The inlet and outlet each having an opening having a cross-sectional area for letting gas flow through. The first and second barriers are configured to modify the cross-sectional areas of the openings when actuated. The actuator is configured to actuate the barriers, and the controller is configured to direct the actuator to actuate the barriers so that the cross-sectional area of the first opening is larger than the cross-sectional area of the second opening so that a pressure at the inlet is greater than a pressure at the outlet.

Sartin, Bryan↗
DOE OSTI2023

Cooling assembly for a turbine assembly

A cooling assembly includes a coolant chamber disposed inside an airfoil of a turbine assembly that directs coolant inside the airfoil. The airfoil extends between a leading edge and a trailing edge along an axial length of the airfoil. Inlet cooling channels are fluidly coupled with the coolant chamber and direct the coolant in a direction toward a trailing edge chamber of the airfoil. The trailing edge chamber is fluidly coupled with at least one inlet cooling channel. The trailing edge chamber is disposed at the trailing edge of the airfoil and includes an inner surface. The inlet cooling channels direct at least a portion of the coolant in a direction toward the inner surface of the trailing edge chamber. One or more outlet cooling channels direct at least a portion of the coolant in one or more directions away from the trailing edge chamber.

Rathay, Nicholas William↗
DOE OSTI2023

Hollow lattice thermal energy storage heat exchanger

Example heat exchangers and methods of use are described herein. An example heat exchanger includes a lattice structure including a plurality of conduits defining a plurality of interstitial voids between the plurality of conduits. Each of the plurality of conduits includes an inlet and an outlet, and the plurality of conduits are arranged such that, between the inlet and the outlet, each of the conduits intersects at least one other conduit to enable flow between the intersecting conduits. The example heat exchanger also includes a first manifold formed unitarily with the lattice structure, the first manifold comprising a first plurality of openings in fluid communication with each inlet of the plurality of conduits. The example heat exchanger further includes a phase change material (PCM) disposed within and substantially filling the plurality of interstitial voids.

Stoia, Michael F.↗
DOE OSTI2023

Refinery gas processing method

A process for hydrogen recovery from refinery gas system comprising supplying the refinery gas to an inlet manifold fluidly coupled to a conditioning stage, the conditioning stage comprising a reactor having a reforming catalyst deposited on an ultra-short-channel-length metal substrate; supplying oxidant to the conditioning stage via the inlet manifold; supplying steam from a steam generator to the conditioning stage via the inlet , manifold; reacting the refinery gas in the conditioning stage; and discharging a product through a discharge outlet fluidly coupled to the conditioning stage, the discharge outlet configured to flow the product for use by a downstream reformer. The process allows to either increase the H2 production rate or lower the firing rate while maintaining a constant H2 production rate for the downstream steam reformer, independent of the feed compositional variability of the refinery or still gas.

Vilekar, Saurabh↗
DOE OSTI2023

Insert device for fuel injection

An insert device includes a body having an upper body portion configured to couple with a cylinder head of an engine cylinder and a lower body portion extending from the upper body portion toward a combustion chamber of the engine cylinder. The body includes an interior surface extending around a central volume positioned to receive liquid fuel from a fuel injector. The body includes gas inlet channels and fuel-and-gas mixture outlet channels. The gas inlet channels direct gas into the central volume where the gas mixes with the liquid fuel to form the fuel-and-gas mixture. The fuel-and-gas mixture outlet channels direct the mixture into the combustion chamber. The interior surface includes concave surface portions between the inlet channels and the outlet channels along a center axis of the body that are shaped to direct the gas into the central volume toward the liquid fuel in the central volume.

Heher, Brett↗
DOE OSTI2024

Systems and methods for periodic nodal surface based reactors, distributors, contactors and heat exchangers

The present disclosure relates to a transport mechanism apparatus for transporting at least one of a gas or a fluid. The transport mechanism may have an inlet, an outlet and an engineered cellular structure forming a periodic nodal surface, which may include a triply periodic minimal surface (TPMS) structure. The structure is formed in a layer-by-layer three dimensional (3D) printing operation to include cells propagating in three dimensions, where the cells include non-intersecting, continuously curving wall portions having openings, and where the opening in the cells form a plurality of flow paths throughout the transport mechanism from the inlet to the outlet, and where portions of the cells form the inlet and the outlet.

Iyer, Jaisree Kannan↗
DOE OSTI2025

Thermal Evaluation of CCS and NACS Reference Devices and Adapters

It is important for manufacturers of electric vehicle charging connectors, inlets, and adapters to understand the thermal performance of their devices. Various standards, such as SAE J1772, SAE J3400, IEC 62196, UL 2251, and UL 2252, list temperature limits that charging hardware needs to meet. However, there are currently very limited standardized reference devices against which to measure connector performance, and those that do currently exist generally serve charging currents less than 500A. This can make determining whether a charging connector meets the appropriate temperature limits difficult. Additionally, as automakers and charging station suppliers transition from the SAE J1772 CCS charging standard to SAE J3400 NACS, a number of CCS-to-NACS and NACS-to-CCS adapters are entering the market. These devices are being produced both by well-known automakers/equipment OEMs and lesser-known third-party suppliers, across a wide range of price points and construction qualities. Though SAE J3400/1 and UL 2252 lay out standards for adapter construction, performance and overtemperature response, there is no guarantee that any particular adapter will follow these standards and react to overtemperature events appropriately. This work addresses these issues by developing and evaluating a set of CCS and NACS reference inlet devices to validate the performance of charging connectors in the 500-800A range. The work also evaluates the performance of multiple NACS-to-CCS and CCS-to-NACS charging adapters with respect to UL 2252 temperature limits and SAE J3400/1 overtemperature signaling criteria.

33 ADVANCED PROPULSION SYSTEMS↗