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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 37 records · Page 2

Measure Guideline: Implementing a Plenum Truss for a Compact Air Distribution System

This Measure Guideline presents the steps to implement a compact duct system inside an attic bulkhead (plenum truss) of a one-story, slab-on-grade (SOG) home. In a compact duct design, ductwork runs are reduced in length to yield a smaller and more compact duct system. Less energy will be lost through ductwork if the ducts are contained within the thermal enclosure of the house. These measures are intended for the production builder working to meet the 2012 International Energy Conservation Code (IECC) requirements and keep the ductwork within the thermal enclosure of the house. This measure of bringing the heating, ventilation and air conditioning (HVAC) equipment and ductwork within the thermal enclosure of the house is appropriate for the builder wishing to avoid cathedralizing the insulation in the attic space (i.e., locating it at the underside of the roof deck rather than along the attic floor) or adding dropped soffits.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Measure Guideline: Implementing a Plenum Truss for a Compact Air Distribution System

This Measure Guideline presents the steps to implement a compact duct system inside an attic bulkhead (plenum truss) of a one-story, slab-on-grade home. In a compact duct design, ductwork runs are reduced in length to yield a smaller and more compact duct system. Less energy will be lost through ductwork if the ducts are contained within the thermal enclosure of the house. These measures are intended for the production builder working to meet the 2012 International Energy Conservation Code (IECC) requirements and keep the ductwork within the thermal enclosure of the house. This measure of bringing the heating, ventilation and air conditioning (HVAC) equipment and ductwork within the thermal enclosure of the house is appropriate for the builder wishing to avoid cathedralizing the insulation in the attic space (i.e., locating it at the underside of the roof deck rather than along the attic floor) or adding dropped soffits.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Technology Solutions Case Study: Sealed Air-Return Plenum Retrofit

In this project, Pacific Northwest National Laboratory researchers greatly improved indoor air quality and HVAC performance by replacing an old, leaky air handler with a new air handler with an air-sealed return plenum with filter; they also sealed the ducts, and added a fresh air intake.

air handler↗

CFD Analysis of RLUOB Zone 1 HEPA Filter Plenum and Testing Manifolds

The purpose of this computational fluid dynamics (CFD) analysis is to ensure that Camfil Farr’s upstream and downstream injection and sampling manifolds can meet or exceed the requirements outlined in the ASME AG-1 1997 a(2000) Code on Nuclear Air and Gas Treatment for the testing of HEPA and adsorbent filters. This paper will present a numerical simulation of airflow in the Radiological Laboratory Utility Office Building (RLUOB) zone 1 HEPA filter plenum and testing manifolds using the commercial CFD software ANSYS FLUENT 2020R1. The CFD analysis focuses on the investigation of the air flow distribution and air-aerosol mixing uniformity. The evaluation was done for all steps of the modeling process: grid generation, physics setup, simulation, and post-processing. The mass flow rate in each section of the zone 1 injection and sampling manifolds is also reported.

42 ENGINEERING↗

OSU High Temperature Test Facility Test Acceptance Report, PG-28 Low Power (<350kW) Lower Plenum Mixing Test

Test Acceptance Report for Test PG-28 at the Oregon State University High Temperature Test Facility. The purpose of this test is to investigate the impact on Lower Plenum thermal profiles and mixing due to changes in the system mass flow rate in an integral test facility scaled to General Atomics’ Modular High Temperature Gas Reactor (MHTGR) design.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

OSU High Temperature Test Facility Test Acceptance Report, PG-30 Low Power (<350kW) Lower Plenum Mixing, Constant Temperature Test

Test Acceptance Report for Test PG-30 at the Oregon State University High Temperature Test Facility. The purpose of this test is to investigate the impact on Lower Plenum thermal profiles and mixing due to changes in the system mass flow rate in an integral test facility scaled to General Atomics’ Modular High Temperature Gas Reactor (MHTGR) design.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

An intelligent scanning algorithm for lost fuel rod recovery in the MYRRHA lower plenum

This paper presents a system for visualizing the interior structure of a vessel filled with a liquid metal. Due to the opaque and conductive nature of the medium, regular visualization systems based on cameras, electromagnetic or laser based techniques can't be used. The operation, strengths and weaknesses of an existing set-up are investigated by creating a scenario to find and extract a rectangular object inside the vessel in the shortest possible time. The main focus of this paper is not on designing a new system but to investigate the bottlenecks that are faced and need to be kept in mind in future designs. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

Effects of additively manufactured surface roughness on small diameter plenums with multiple side discharges for high temperature gas turbine blade cooling applications

Combined heat and power (CHP) applications have significant environmental and economic benefits that are consistent with the goals of the U.S. Department of Energy (DOE). One area that is currently being studied includes the potential benefits of CHP turbine operation at higher turbine inlet temperatures. Internal cooling concepts enabled by additive manufacturing (AM) are of primary interest. Here, the effectiveness of internal cooling is hindered by many factors such as velocity distribution of the cooling air to the hot surface considering impingement cooling. To simulate cooling air exiting from a series of orifices for internal cooling in an airfoil, a straight smooth wall tubing with multiple side discharging orifices is used and compared to additively manufactured tubing (Ti6Al4V Grade 23) with orifice size and spacing as well as inner and outer diameters identical to the smooth wall tubing. Similar to flow discharging form perforated pipes, the flow discharged from individual orifices along the tubes in this study is found to be nonuniformly distributed, and the horizontal (axial direction) momentum can be observed from the experimental data. Discharge velocities have been measured with two-dimensional (2D) particle imaging velocimetry (PIV) and single element hot wire anemometry. Numerical analysis has also been conducted to predict the velocity distributions along the orifices in the smooth wall and additive manufacturing (AM) tubing, which are inherited with surface roughness. Numerical and measured results in this study are compared, presented, and discussed.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Multiple stack fuel cell system with shared plenum

A multi-stack fuel cell system is disclosed where multiple fuel cell stacks can be efficiently connected together. The fuel cell system includes a plurality of fuel cell modules include a sealed planar fuel cell stack that has internal manifold channels for transport of fuel and air to fuel cells within the stack and transport of tail gas and spent air away from fuel cells within the stack. Each of the fuel cell stacks is mounted on a base manifold, and the base manifold has side openings in fluid communication with the stack internal manifold channels. The side openings on the base manifold are configured so that the modules can be efficiently connected together.

Schneider, Jonathan↗

Uncertainty analysis of a SFR core with sodium plenum

The new concepts of Sodium-cooled Fast Reactors have to reach the Generation IV safety objectives. In this regard the Sodium Void Effect has to be minimized for the future projects of large-size SFR as well as the uncertainties on it. The Inst. of Radiological Protection and Nuclear Safety (IRSN) as technological support of French public authorities is in charge of safety assessment of operating and under construction reactors, as well as future projects. In order to state about the safety of new SFR designs the IRSN must be able to evaluate core parameters and their uncertainties. In this frame a sensitivity and uncertainty study has been performed to evaluate the impact of nuclear data uncertainty on sodium void effect, for the benchmark model of large SFR BN-800. The benchmark parameters (effective multiplication factor and sodium void effect) have been evaluated using two codes, the deterministic code ERANOS and the Monte Carlo code SCALE, while the S/U analysis has been performed only with SCALE. The results of the these studies point out the most relevant cross section uncertainties that affect the SVE and how efforts should be done in increasing the existing nuclear data accuracies. (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Toward Linear Stability Analysis of Upper Plenum Flows

Linear stability analysis is a tool used to help identify the sensitivity of a particular domain to perturbations and evaluate the system dynamics as a transition, if any, occurs. The development of a time invariant base flow for future use in a linear stability analysis is the focus of this investigation. A test case, with a Reynolds number of 100, was brought to a steady state using the spectral element code Nek5000 and the method of selective frequency damping. The convergence criteria for this method is the volume averaged value of the forcing function which, after approximately 80,000 time-steps, decreased to 3.6x10{sup -4}. Analysis shows that the case has yet to have reached the tolerance desired, 1x10{sup -6}. With the simulation in the process of converging a preliminary perturbation analysis was conducted. Due to the low Reynolds number of this case, 100, it was hypothesized that the flow would be linearly stable. This preliminary stability analysis only focused on the largest fundamental mode and the energy growth of that perturbation over time. Upon evaluation of the perturbation energy, which was shown to be monotonically decreasing in time, it was concluded that, despite not yet being converged, the system is in fact linearly stable. Future work includes evaluating the domain at higher Reynolds numbers, solving the eigenvalue problem created when the linearized Navier-Stokes are written in operator form and calculating the energy evolution of the optimal perturbation. (authors)

42 ENGINEERING↗

Apparatus and method for mixing fuel in a gas turbine nozzle

A nozzle includes a fuel plenum and an air plenum downstream of the fuel plenum. A primary fuel channel includes an inlet in fluid communication with the fuel plenum and a primary air port in fluid communication with the air plenum. Secondary fuel channels radially outward of the primary fuel channel include a secondary fuel port in fluid communication with the fuel plenum. A shroud circumferentially surrounds the secondary fuel channels. A method for mixing fuel and air in a nozzle prior to combustion includes flowing fuel to a fuel plenum and flowing air to an air plenum downstream of the fuel plenum. The method further includes injecting fuel from the fuel plenum through a primary fuel passage, injecting fuel from the fuel plenum through secondary fuel passages, and injecting air from the air plenum through the primary fuel passage.

42 ENGINEERING↗