Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “cooled”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 883 records · Page 49
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Development of the electron cooling simulation program for MEIC

In the medium energy electron ion collider (MEIC) project at Jefferson Lab, the traditional electron cooling technique is used to reduce the ion beam emittance at the booster ring, and to compensate the intrabeam scattering effect and maintain the ion beam emittance during collision at the collider ring. A DC cooler at the booster ring and a bunched beam cooler at the collider ring are proposed. To fulfil the requirements of the cooler design for MEIC, we are developing a new program, which allows us to simulate the following cooling scenarios: DC cooling to coasting ion beam, DC cooling to bunched ion beam, bunched cooling to bunched ion beam, and bunched cooling to coasting ion beam. The new program has been benchmarked with existing code in aspect of accuracy and efficiency. The new program will be adaptive to the modern multicore hardware. We will present our models and some simulation results.

Zhang, He↗
DOE OSTI2019

Optical Stochastic Cooling Program at Fermilab's Integrable Optics Test Accelerator

Beam cooling enables an increase of peak and average luminosities and significantly expands the discovery potential of colliders. Optical Stochastic Cooling (OSC) is a high-bandwidth cooling technique that will advance the present state-of-the-art, stochastic-cooling rate by more than three orders of magnitude. A proof-of-principle demonstration with protons or heavy ions involves prohibitive costs, risks and technological challenges; however, exploration of OSC with electrons is a cost-effective alternative for studying the beam-cooling physics, optical systems and diagnostics. The ability to demonstrate OSC was a key requirement in the design of Fermilab's Integrable Optics Test Accelerator (IOTA) ring. The IOTA program will explore the physics and technology of OSC in amplified and non-amplified configurations. We also plan to investigate the cooling and manipulation of a single electron stored in the ring. The OSC apparatus is currently being fabricated, and installation will begin in the fall of 2019. In this contribution, we will describe the IOTA OSC program, the upcoming passive-OSC experimental runs and ongoing preparations for an amplified-OSC experiment

43 PARTICLE ACCELERATORS↗
DOE OSTI2019

Optical Stochastic Cooling Program at Fermilab's Integrable Optics Test Accelerator

Beam cooling enables an increase of peak and average luminosities and significantly expands the discovery potential of colliders. Optical Stochastic Cooling (OSC) is a high-bandwidth cooling technique that will advance the present state-of-the-art, stochastic-cooling rate by more than three orders of magnitude. A proof-of-principle demonstration with protons or heavy ions involves prohibitive costs, risks and technological challenges; however, exploration of OSC with electrons is a cost-effective alternative for studying the beam-cooling physics, optical systems and diagnostics. The ability to demonstrate OSC was a key requirement in the design of Fermilab's Integrable Optics Test Accelerator (IOTA) ring. The IOTA program will explore the physics and technology of OSC in amplified and non-amplified configurations. We also plan to investigate the cooling and manipulation of a single electron stored in the ring. The OSC apparatus is currently being fabricated, and installation will begin in the fall of 2019. In this contribution, we will describe the IOTA OSC program, the upcoming passive-OSC experimental runs and ongoing preparations for an amplified-OSC experiment.

43 PARTICLE ACCELERATORS↗
DOE OSTI2020

Turbine component and methods of making and cooling a turbine component

A turbine component includes a root and an airfoil extending from the root to a tip opposite the root. The airfoil forms a leading edge and a trailing edge portion extending to a trailing edge. A plurality of axial cooling channels in the trailing edge portion of the airfoil are arranged to permit axial flow of a cooling fluid from an interior of the turbine component at the trailing edge portion to an exterior of the turbine component at the trailing edge portion. A method of making a turbine component includes forming an airfoil having a trailing edge portion with axial cooling channels. The axial cooling channels are arranged to permit axial flow of a cooling fluid from an interior to an exterior of the turbine component at the trailing edge portion. A method of cooling a turbine component is also disclosed.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2020

Energy efficient data center liquid cooling with geothermal enhancement

A data center cooling system is operated in a first mode, has an indoor portion wherein heat is absorbed from components in the data center by a heat transfer fluid, and has an outdoor heat exchanger portion and a geothermal heat exchanger portion. The first mode includes ambient air cooling of the heat transfer fluid in the outdoor heat exchanger portion and/or geothermal cooling of the heat transfer fluid in the geothermal heat exchanger portion. Based on an appropriate metric, a determination is made that a switch should be made from the first mode to a second, different, mode; and, responsive thereto, the data center cooling system is switched to the second mode. The second mode includes at least another of ambient air cooling of the heat transfer fluid in the outdoor heat exchanger portion and geothermal cooling of the heat transfer fluid in the geothermal heat exchanger portion.

15 GEOTHERMAL ENERGY↗
DOE OSTI2021

Baseline Airfoil Cooling Designs For 5-10MW Gas Turbines

This paper describes conventional cooling technologies that have been identified after a thorough review of public literature as a baseline for more detailed analysis and future testing. This effort is unique because the cooling features (i.e., leading edge, mid-chord, and trailing edge) are integrated together within an airfoil of realistic scale. The engineering models that have been developed to characterize the cooling performance for these baseline configurations will be described. It is believed that the cooling designs described in this paper are representative of gas turbines in the 5-10 MWe size range, but not identical to any commercial product. The present effort to establish a state-of-the-art cooling scheme is a first, and necessary, step in an on-going project to identify and test more advanced cooling concepts for CHP systems that are enabled by additive manufacturing.

Straub, Douglas↗
DOE OSTI2021

Baseline Airfoil Cooling Designs For 5-10MW Gas Turbines - Conference Paper

This paper describes conventional cooling technologies that have been identified after a thorough review of public literature as a baseline for more detailed analysis and future testing. This effort is unique because the cooling features (i.e., leading edge, mid-chord, and trailing edge) are integrated together within an airfoil of realistic scale. The engineering models that have been developed to characterize the cooling performance for these baseline configurations will be described. It is believed that the cooling designs described in this paper are representative of gas turbines in the 5-10 MWe size range, but not identical to any commercial product. The present effort to establish a state-of-the-art cooling scheme is a first, and necessary, step in an on-going project to identify and test more advanced cooling concepts for CHP systems that are enabled by additive manufacturing.

Straub, Douglas↗
DOE OSTI2017

Hybrid Membrane-based Ionic Liquid Absorption Cycle for Water Heating, Dehumidification, and Cooling

To meet the growing energy consumption and mitigate climate concerns, novel energy efficient technologies need to be developed. Water heating, dehumidification and space cooling form a significant percentage (~24%) of a typical U.S. household energy consumption and a total of 2.6 quad of primary energy consumption. In this paper, we present a novel system for combined water heating, dehumidification, and space cooling. The three processes can be achieved by one device using a novel semi-open absorption based system combined with evaporative cooling. The absorption based system absorbs water vapor from its ambient. The latent heat of absorption, released into the absorbent, is transferred into the process water that cools the absorbent. The water absorbed is later released in the desorber through heating, and the water vapor generated in the desorber is condensed and its heat of phase change is transferred to the process water in the condenser. The condensed water vapor can either be drained if dehumidification is desired or be used in an evaporative cooling process for space cooling. The major innovations that enable such an absorption-based device are demonstrated in this study through an experimental test setup. First, a membrane based absorption system in a compact and scalable platform is used to alleviate the liquid entrainment issue encountered in the conventional packed bed absorbers. Second, architecture reconfigurations, like novel fluid circuits and semi-open absorption system are deployed to enhance performance and lower system cost. Finally, an ionic liquid is implemented to minimize corrosion and eliminate crystallization risks, a major concern with conventional salts. The water heating and dehumidification component of the device are experimentally evaluated and the device is characterized for various system parameters. A water heating COP of 1.4 is achieved in this first generation prototype. These innovations pave the way for a compact, efficient, and low cost absorption based system for residential scale applications.

CHUGH, Devesh↗
DOE OSTI2022

Energy efficient data center liquid cooling with geothermal enhancement

A data center cooling system is operated in a first mode, has an indoor portion wherein heat is absorbed from components in the data center by a heat transfer fluid, and has an outdoor heat exchanger portion and a geothermal heat exchanger portion. The first mode includes ambient air cooling of the heat transfer fluid in the outdoor heat exchanger portion and/or geothermal cooling of the heat transfer fluid in the geothermal heat exchanger portion. Based on an appropriate metric, a determination is made that a switch should be made from the first mode to a second, different, mode; and, responsive thereto, the data center cooling system is switched to the second mode. The second mode includes at least another of ambient air cooling of the heat transfer fluid in the outdoor heat exchanger portion and geothermal cooling of the heat transfer fluid in the geothermal heat exchanger portion.

Chainer, Timothy J.↗
DOE OSTI2022

Turbine component and methods of making and cooling a turbine component

A turbine component includes a root and an airfoil extending from the root to a tip opposite the root. The airfoil forms a leading edge and a trailing edge portion extending to a trailing edge. A plurality of axial cooling channels in the trailing edge portion of the airfoil are arranged to permit axial flow of a cooling fluid from an interior of the turbine component at the trailing edge portion to an exterior of the turbine component at the trailing edge portion. A method of making a turbine component includes forming an airfoil having a trailing edge portion with axial cooling channels. The axial cooling channels are arranged to permit axial flow of a cooling fluid from an interior to an exterior of the turbine component at the trailing edge portion. A method of cooling a turbine component is also disclosed.

Dutta, Sandip↗
DOE OSTI2015

A GPU Accelerated Simulation Program for Electron Cooling Process

Electron cooling is essential to achieve high luminosity in the medium energy electron ion collider (MIEC) project at Jefferson Lab. Bunched electron beam with energy above 50 MeV is used to cool coasting and/or bunched ion beams. Although the conventional electron cooling technique has been widely used, such an implementation in MEIC is very challenging. We are developing a simulation program for the electron cooling process to fulfill the need of the electron cooling system design for MEIC. The program simulates the evolution of the ion beam under the intrabeam scattering (IBS) effect and the electron cooling effect using Monte Carlo method. To accelerate the calculation, the program is developed on a GPU platform. We will present some preliminary simulation results.

Zhang, He↗
DOE OSTI2023

Adsorption cooling system using metal organic frameworks

An adsorptive cooling system includes two highly adsorptive structures positioned to receive thermal energy from a thermal energy source, each highly adsorptive structure includes a substrate and a metal-organic framework (MOF) coupled to the respective substrate and adapted for adsorbing and desorbing a refrigerant under predetermined thermodynamic conditions. The adsorptive cooling system includes a cooling unit and a circulation system adapted for circulating the refrigerant from one of the highly adsorptive structures to the cooling unit to provide cooling from the thermal energy source and to return the refrigerant from the cooling unit to the same or other highly adsorptive structure. Each substrate may include a plurality of microchannels, providing ingress and egress paths for a refrigerant, defined by grooves in a surface of the substrate nearest the MOF and/or surfaces of a plurality of microcapillaries of the substrate. The microchannels provide ingress and egress paths for a refrigerant.

Baumann, Theodore F.↗
DOE OSTI2023

Two-point and multiple-point spot heating and cooling

Apparatus and methods for producing thermal comfort using two point or multipoint heating or cooling that is applied to portion of a human body part to produce a warm or cool sensation over a larger area than that where the heating or cooling is directly applied. The body is induced to heat or cool itself by adjusting its neutral temperature setpoints. Increased warming perception from two-point, multipoint, and switching point stimulation causes downward adaptation in the neutral skin temperature of the user. Because spot heating and cooling sources operate at higher temperature differences from the skin than do area sources, they create a stronger perceived thermal sensation for the same power consumption. Point heating or cooling, rather than whole-area heating, can result in power savings and cost savings while improving occupant comfort.

Arens, Edward↗
DOE OSTI2024

Experimental Investigation on Cooling performance of A Thermoelectric Freezer

Thermoelectric heat pumps (TEHPs) have found widespread use in the electronics cooling industry and portable refrigerators. However, there has been a lack of extensive research on the application of TEHPs in low-temperature refrigeration settings. To address this gap, various configurations of TEHPs were fabricated to assess their suitability for freezer applications. Key parameters such as cooling capacity and system performance of the TEHPs were crucial in evaluating these configurations. Three configurations, each with different numbers of cooling units and fan arrangements, were tested using a 300-liter freezer prototype under typical room conditions (21°C). A cooling unit is comprised of two-stage thermoelectric modules, an aluminum plate fin heat exchanger sink with fans positioned either on top or directing airflow through the center, and a cooling block with circulating icy water for heat dissipation. Across all configurations, the minimum temperature inside the freezer cabinet reached -16.0°C. The cooling capacity peaked at 74.7 W, with the thermoelectric coefficient of performance (COP) reaching a maximum of 0.45. System COP ranged from 0.23 to 0.28. Minimum TE power consumption was recorded at 138.8 W, with TE system power consumption at 174.4 W, indicating feasibility for practical residential freezer applications. This investigation lays the foundation for integrating TE freezers with ice thermal storage systems.

Hu, Yifeng↗
DOE OSTI2024

Systems and methods for laser diode array having integrated microchannel cooling

The present disclosure relates to a laser diode system. The system may have at least one laser diode emitter having a substrate, at least one laser diode supported on the substrate, and a facet which a laser beam generated by the laser diode is emitted. A cooling subsystem is included which is disposed in contact with the substrate of the laser diode emitter. The cooling subsystem includes a plurality of cooling fins forming a plurality of elongated channels for circulating a cooling fluid therethrough to cool the laser diode emitter. The cooling fluid also flows over the facet of the laser diode emitter.

Kotovsky, Jack↗
DOE OSTI2018

Impact of post-rainfall evaporation from porous roof tiles on building cooling load in subtropical China

Rainfall occurs frequently in subtropical regions of China, with the subsequent water evaporation from building roofs impacting the thermal performance and the energy consumption of buildings. In this paper, we proposed a novel simulation method using actual meteorological data to evaluate this impact. New features were developed in EnergyPlus to enable the simulation: (1) an evaporation latent heat flux source term was added to the heat balance equation of the external surface and (2) algorithms for the evaporative cooling module (ECM) were developed and implemented into EnergyPlus. The ECM experimental results showed good agreement with the simulated results. The ECM was used to assess the impact of evaporation from porous roof tiles on the cooling load of a one-floor building in subtropical China. The results show that the evaporation process decreased the maximal values of the external and internal roof surface temperatures by up to 6.4 °C and 3.2 °C, respectively, while the lower internal surface temperature decreased the room accumulated cooling load by up to 14.8% during the hot summer period. Lastly, the enhanced EnergyPlus capability can be used to evaluate the evaporative cooling performance of roofs with water-storage mediums, as well as to quantify their impact on building cooling loads.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2020

Thin hybrid capillary two-phase cooling system

A novel hybrid two-phase cooling system was developed that integrated a mechanically pumped two-phase loop with a capillary-driven two-phase cooling device. The latter cooling mechanism was based on evaporation/boiling from wick structures made by sintering copper particles on the interior surfaces of a copper cold plate. The cold plate provided cooling to two surfaces and each of them included four heaters in series. The novelty of the developed technology was preventing flooding of the evaporator wicks by isolating the evaporation surface from the pumped liquid flow that fed them. This arrangement allowed for a high liquid feed flow rate much greater than would be allowed by a capillary pumped system while maintaining a low thermal resistance at the evaporation surface. Using this approach, the cooling system removed over 850 W with a low pumping power below 1.0 W while using R245fa as the working fluid. The equivalent heat fluxes exceeded 970 W/cm 2 over areas less than 0.12 cm 2 . The measured thermal resistance was as low as 0.09 K-cm 2 /W. The presented thermal management solution enables an increase in the power of high heat flux electronic devices beyond the state-of-the-art.

42 ENGINEERING↗
DOE OSTI2022

Two-tone Doppler cooling of radial two-dimensional crystals in a radio-frequency ion trap

We study the Doppler-cooling of radial two-dimensional (2D) Coulomb crystals of trapped barium ions in a radiofrequency trap. Ions in radial 2D crystals experience micromotion of an amplitude that increases linearly with the distance from the trap center, leading to a position-dependent frequency modulation of laser light in each ion's rest frame. We use two tones of Doppler-cooling laser light separated by approximately 100 MHz to efficiently cool distinct regions in the crystals with differing amplitudes of micromotion. This technique allows us to trap and cool more than 50 ions populating 4 shells in a radial two-dimensional crystal, where with a single tone of Doppler cooling light we are limited to 30 ions in 3 shells. Here, we also individually characterize the micromotion of all ions within the crystals, and use this information to locate the center of the trap and to determine the Matthieu parameters q x and q y .

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗