Results 1 - 10 of 2067
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[en] This report was written as part of a United States Department of Energy (DOE), Office of Nuclear Energy, Advanced Reactor Technologies program funded project to re-create the capabilities of the legacy Centralized Reliability Database Organization (CREDO) database. The CREDO database provided a record of component design and performance documentation across various systems that used sodium as a working fluid. Regaining this capability will allow the DOE complex and the domestic sodium reactor industry to better understand how previous systems were designed and built for use in improving the design and operations of future loops. The contents of this report include: overview of the current state of domestic sodium reliability databases; summary of the ongoing effort to improve, understand, and process the CREDO information; summary of the initial efforts to develop a unified sodium reliability database called the Sodium System Component Reliability Database (NaSCoRD); and explain both how potential users can access the domestic sodium reliability databases and the type of information that can be accessed from these databases.
[en] This report describes the status of the development of MELCOR Sodium Chemistry (NAC) package. This development is based on the CONTAIN-LMR sodium physics and chemistry models to be implemented in MELCOR. In the past three years, the sodium equation of state as a working fluid from the nuclear fusion safety research and from the SIMMER code has been implemented into MELCOR. The chemistry models from the CONTAIN-LMR code, such as the spray and pool fire mode ls, have also been implemented into MELCOR. This report describes the implemented models and the issues encountered. Model descriptions and input descriptions are provided. Development testing of the spray and pool fire models is described, including the code-to-code comparison with CONTAIN-LMR. The report ends with an expected timeline for the remaining models to be implemented, such as the atmosphere chemistry, sodium-concrete interactions, and experimental validation tests .
[en] This paper presents a novel silicone-based, millimeter-scale, fluidic actuator able to bend about two orthogonal axes. The implemented molding fabrication procedure is discussed and the quasi-static performance of the developed prototypes is experimentally investigated. The relationship between the pressurized working fluid and the position of the actuator tip is determined by using a stereovision measurement system. Such a relationship is mapped through a regression model, which is used to implement a minimalist position controller. (paper)
[en] The delivery of working fluid to the cutting zone in a current of steam supplied by a steam generator is considered. This method improves the machining of metals, reduces tool wear, and improves the surface quality of the product.
[en] Highlights: • Flow characteristics of the MPHP with reentrant cavities are investigated. • Reentrant cavities in the MPHPs are shown to promote nucleation and early startup. • The thermal resistance of the MPHP with reentrant cavities is decreased by up to 57%. • A single MPHP incorporating various sizes of reentrant cavities is proposed. - Abstract: This study is performed to investigate the effect of the size of reentrant cavities on the thermal performance of a micro pulsating heat pipe (MPHP). The flow and thermal characteristics of the MPHPs with each MPHP having a different size of reentrant cavities, along with a MPHP without reentrant cavities are experimentally obtained and compared. Silicon-based MPHPs with and without reentrant-type artificial cavities inside the channels are fabricated using MEMS techniques. The MPHPs have rectangular channels which are engraved on a silicon wafer with a hydraulic diameter of 667 . Ethanol is used as the working fluid. To allow for flow visualization, the etched micro-channels are covered with a transparent glass. Each MPHP with reentrant cavities has reentrant cavities of one size, which are either 10, 20, 30, or 40 , respectively. Reentrant cavities in the MPHPs are shown to promote nucleation and early startup. Furthermore, the thermal resistance of the MPHP with reentrant cavities is decreased by up to 57%. As the size of the reentrant cavities increases, lower input power is required for startup, and the MPHP with the largest cavities (40 ) shows the earliest startup. On the contrary, as the size of the reentrant cavities decreases, a reduction of the thermal resistance of the MPHPs is maintained to higher input power, and the MPHP with the smallest cavities (10 ) shows the lowest thermal resistance at high input power (>12 W). Finally, a single MPHP incorporating various sizes of reentrant cavities (10, 20, 30, and 40 ) is shown to exhibit extended operating range and enhanced thermal performance simultaneously.
[en] The performance concept and peculiarities of the new type of thermal diode with the trap and with the wick breakage are dealt with in the report. The experimental data were obtained and analysed for the working fluid mass and the volume of the liquid in the wick on the forward-mode limiting heat transfer. The flow rate pulsation of the working fluid in the wick was observed visually on the setup with the transparent wall. The quantitative difference on the data on the investigated thermal diode and on the identical heat pipes without the wick breakage is found experimentally concerning the forward-mode limiting heat transfer. 10 references
[en] A cryostat of the Dewar-flask type for maintaining extremely low, substantially constant temperatures for various detectors or other devices in good heat conducting relationship with the liquid nitrogen or other cryogen which cryostat has plural ports for accepting the detector assembly so as to permit multi-axial detector placement in the same cryostat without structural modification
[en] This paper tries to give a general description of a thermodynamic cycle (whatever kind and number of transformations) as a function of a set of independent parameters characterising thermodynamic transformations, as well as of constraints imposed on the cycle by plant physical nature, lay-out and controls. An 'Associated Reversible Transformation' (A.R.T.), defined in the paper, is used to describe each real thermodynamic transformation of working fluid, similarly to well-known description of ideal gas adiabatic compression by means of a polytropic transformation, so that A.R.T. may be regarded as polytropics generalised. A simple gas cycle is used to present an application of A.R.T. in the field of energy Diagnosis, underlining usefulness of a complete set of independent parameters for cycle description. Further application in the fields of second law analysis and thermoeconomics are outlined in the concluding part of the paper