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Analytical comparison of turbine-blade cooling systems designed for a turbojet engine operating at supersonic speed and high altitude 1: liquid-cooling systems

Description: Report presenting an investigation of the influence of high-altitude supersonic flight on the operation and effectiveness of turbine-blade liquid-cooling systems for application in turbojet engines in guided missiles and in supersonic aircraft. The problems encountered in liquid-cooling systems were investigated with reference to several specific designs for alternate heat-rejection mediums.
Date: February 20, 1953
Creator: Schramm, Wilson B.; Nachtigall, Alfred J. & Arne, Vernon L.
Partner: UNT Libraries Government Documents Department

Preliminary Model Tests of a Wing-Duct Cooling System for Radial Engines, Special Report

Description: "Wind-tunnel tests were conducted on a model wing-nacelle combination to determine the practicability of cooling radial engines by forcing the cooling air into wing-duct entrances located in the propeller slipstream, passing the air through the engine baffles from rear to front, and ejecting the air through an annular slot near the front of the nacelle. The drag of the cowlings tested was definitely less than for the conventional N.A.C.A. cowling, and the pressure available at low air speed corresponding to operation on the ground and at low flying speeds was apparently sufficient for cooling most present-day radial engines" (p. 1).
Date: February 1939
Creator: Biermann, David & Valentine, E. Floyd
Partner: UNT Libraries Government Documents Department

A Proposal to Upgrade the Silicon Strip Detector

Description: The STAR Silicon Strip Detector (SSD) was built by a collaboration of Nantes, Strasbourg and Warsaw collaborators. It is a beautiful detector; it can provide 500 mu m scale pointing resolution at the vertex when working in combination with the TPC. It was first used in Run 4, when half the SSD was installed in an engineering run. The full detector was installed for Run 5 (the Cu-Cu run) and the operation and performance of the detector was very successful. However, in preparation for Run 6, two noisy ladders (out of 20) were replaced and this required that the SSD be removed from the STAR detector. The re-installation of the SSD was not fully successful and so for the next two Runs, 6 and 7, the SSD suffered a cooling system failure that allowed a large fraction of the ladders to overheat and become noisy, or fail. (The cause of the SSD cooling failure was rather trivial but the SSD could not be removed betweens Runs 6 and 7 due to the inability of the STAR detector to roll along its tracks at that time.)
Date: November 5, 2007
Creator: Matis, Howard; Michael, LeVine; Jonathan, Bouchet; Stephane, Bouvier; Artemios, Geromitsos; Gerard, Guilloux et al.
Partner: UNT Libraries Government Documents Department

Resonance Control Cooling System for the APT/LEDA RFQ

Description: The Radio Frequency Quadrupole (RFQ) resonance control cooling system (RCCS) for the Low Energy Demonstration Accelerator (LEDA) in support of the Accelerator Production of Tritium (APT) is described. Constant flow regulating valves to distribute the required flow to the 424 channels and to permit use of centrifugal pumps is discussed. Control system schema are described to regulate resonance frequency during steady state operation.
Date: November 4, 1998
Creator: Domer, G.A. & Floersch, R.H.
Partner: UNT Libraries Government Documents Department

Gas-turbine-engine performance when heat from liquid-cooled turbines is rejected ahead of, within, or behind main compressor

Description: Report discussing methods, advantages, and disadvantages of locating rotating heat exchangers ahead of, within, and behind the main engine compressor. Heat rejection should occur at the compressor discharge for best engine performance. Results regarding turbojet-engine performance, turboprop-engine performance, and a comparison of engine performance with liquid- and air-cooling are provided.
Date: May 22, 1956
Creator: Esgar, Jack B. & Slone, Henry O.
Partner: UNT Libraries Government Documents Department

In-vessel ITER tubing failure rates for selected materials and coolants

Description: Several materials have been suggested for fabrication of ITER in-vessel coolant tubing: beryllium, copper, Inconel, niobium, stainless steel, titanium, and vanadium. This report generates failure rates for the materials to identify the best performer from an operational safety and availability perspective. Coolant types considered in this report are helium gas, liquid lithium, liquid sodium, and water. Failure rates for the materials are generated by including the influence of ITER`s operating environment and anticipated tubing failure mechanisms with industrial operating experience failure rates. The analyses define tubing failure mechanisms for ITER as: intergranular attack, flow erosion, helium induced swelling, hydrogen damage, neutron irradiation embrittlement, cyclic fatigue, and thermal cycling. K-factors, multipliers, are developed to model each failure mechanism and are applied to industrial operating experience failure rates to generate tubing failure rates for ITER. The generated failure rates identify the best performer by its expected reliability. With an average leakage failure rate of 3.1e-10(m-hr){sup {minus}1}and an average rupture failure rate of 3.1e-11(m-hr){sup {minus}1}, titanium proved to be the best performer of the tubing materials. The failure rates generated in this report are intended to serve as comparison references for design safety and optimization studies. Actual material testing and analyses are required to validate the failure rates.
Date: March 1, 1994
Creator: Marshall, T. D. & Cadwallader, L. C.
Partner: UNT Libraries Government Documents Department

Development of a Low-Lift Chiller Controller and Simplified Precooling Control Algorithm - Final Report

Description: KGS Buildings LLC (KGS) and Pacific Northwest National Laboratory (PNNL) have developed a simplified control algorithm and prototype low-lift chiller controller suitable for model-predictive control in a demonstration project of low-lift cooling. Low-lift cooling is a highly efficient cooling strategy conceived to enable low or net-zero energy buildings. A low-lift cooling system consists of a high efficiency low-lift chiller, radiant cooling, thermal storage, and model-predictive control to pre-cool thermal storage overnight on an optimal cooling rate trajectory. We call the properly integrated and controlled combination of these elements a low-lift cooling system (LLCS). This document is the final report for that project.
Date: November 30, 2011
Creator: Gayeski, N.; Armstrong, Peter; Alvira, M.; Gagne, J. & Katipamula, Srinivas
Partner: UNT Libraries Government Documents Department

Model Predictive Control for the Operation of Building Cooling Systems

Description: A model-based predictive control (MPC) is designed for optimal thermal energy storage in building cooling systems. We focus on buildings equipped with a water tank used for actively storing cold water produced by a series of chillers. Typically the chillers are operated at night to recharge the storage tank in order to meet the building demands on the following day. In this paper, we build on our previous work, improve the building load model, and present experimental results. The experiments show that MPC can achieve reduction in the central plant electricity cost and improvement of its efficiency.
Date: June 29, 2010
Creator: Ma, Yudong; Borrelli, Francesco; Hencey, Brandon; Coffey, Brian; Bengea, Sorin & Haves, Philip
Partner: UNT Libraries Government Documents Department

Common Mode Rejection Calculations on the Debuncher Upgrade

Description: The 4-8 GHz Transverse Debuncher Cooling Systems are power limited. Misalignments and imperfections in the transverse pickup arrays will generate a longitudinal signal in addition to the betatron signal. This longitudinal signal can use up a significant fraction of the precious TWT power if the imperfections are large enough. This note will summarize calculations of the contributions to the longitudinal signal observed in the transverse systems of the 4-8 GHz Debuncher slow-wave pickup arrays due to various misalignments and imperfections.
Date: February 2, 2001
Creator: McGinnis, Dave
Partner: UNT Libraries Government Documents Department

Muon cooling R and D

Description: International efforts are under way to design and test a muon ionization cooling channel. The present R and D program is described, and future plans outlined.
Date: August 22, 2001
Creator: Geer, Steve
Partner: UNT Libraries Government Documents Department

General Heat Transfer Characterization and Empirical Models of Material Storage Temperatures for the Los Alamos Nuclear Materials Storage Facility

Description: The Los Alamos National Laboratory's Nuclear Materials Storage Facility (NMSF) is being renovated for long-term storage of canisters designed to hold heat-generating nuclear materials. A fully passive cooling scheme, relying on the transfer of heat by conduction, free convection, and radiation has been proposed as a reliable means of maintaining material at acceptable storage temperatures. The storage concept involves placing radioactive materials, with a net heat-generation rate of 10 W to 20 W, inside a set of nested steel canisters. The canisters are, in placed in holding fixtures and positioned vertically within a steel storage pipe. Several hundred drywells are arranged in a linear array within a large bay and dissipate the waste heat to the surrounding air, thus creating a buoyancy driven airflow pattern that draws cool air into the storage facility and exhausts heated air through an outlet stack. In this study, an experimental apparatus was designed to investigate the thermal characteristics of simulated nuclear materials placed inside two nested steel canisters positioned vertically on an aluminum fixture plate and placed inside a section of steel pipe. The heat-generating nuclear materials were simulated with a solid aluminum cylinder containing .an embedded electrical resistance heater. Calibrated type T thermocouples (accurate to ~ O.1 C) were used to monitor temperatures at 20 different locations within the apparatus. The purposes of this study were to observe the heat dissipation characteristics of the proposed `canister/fixture plate storage configuration, to investigate how the storage system responds to changes in various parameters, and to develop and validate empirical correlations to predict material temperatures under various operating conditions
Date: October 1, 1998
Creator: Bernardin, J. D. & Gregory, W. S.
Partner: UNT Libraries Government Documents Department

APT cooling water supply make-up trade study. Revision 1

Description: In the conceptual design of the APT cooling water system, several options exist for the design of the system(s) which serve as the ultimate heat sink. This study will evaluate alternative methods of providing an ultimate heat sink to the APT.
Date: August 8, 1996
Creator: Reynolds, R.W. & Hink, R.
Partner: UNT Libraries Government Documents Department

Cooling effects of an airplane equipped with an NACA cowling and a wing-duct cooling system

Description: Report presenting cooling tests of a Northrop A-17A attack airplane equipped with a conventional NACA cowling and then with a wing-duct cooling system. Ground cooling for the wing-duct system without cowl flap was better than for the cowling with flap, but was improved by installing a cowl flap. Satisfactory temperatures were maintained in climb and high-speed flight, but a greater quantity of cooling air was needed for the wing-duct system.
Date: June 1941
Creator: Turner, L. I., Jr.; Bierman, David & Boothy, W. B.
Partner: UNT Libraries Government Documents Department

Design windows for a He cooled fusion reactor

Description: A design window concept is developed for a He-cooled fusion reactor blanket and divertor design. This concept allows study of a parameter regime under which a possible design exists with different design requirements, such as allowable pumping fraction. The concept identifies not only the required parameter regime, but also investigates the robustness of the design, i.e., the validity of the design with change of design parameters and requirements. Some recent directions of helium cooled design for ITER and for divertor can also be explained by this design window concept.
Date: October 1, 1993
Creator: Sze, Dai-Kai & Hassanein, A.
Partner: UNT Libraries Government Documents Department

A robust helium-cooled shield/blanket design for ITER

Description: General Atomics Fusion and Reactor Groups have completed a helium-cooled, conceptual shield/blanket design for ITER. The configuration selected is a pressurized tubes design embedded in radially oriented plates. This plate can be made from ferritic steel or from V-alloy. Helium leakage to the plasma chamber is eliminated by conservative, redundant design and proper quality control and inspection programs. High helium pressure at 18 MPa is used to reduce pressure drop and enhance heat transfer. This high gas pressure is believed practical when confined in small diameter tubes. Ample industrial experience exists for safe high gas pressure operations. Inboard shield design is highlighted in this study since the allowable void fraction is more limited. Lithium is used as the thermal contacting medium and for tritium breeding, its safety concerns are minimized by a modular, low inventory design that requires no circulation of the liquid metal for the purpose of heat removal. This design is robust, conservative, reliable, and meets all design goals and requirements. It can also be built with present-day technology.
Date: November 1, 1993
Creator: Wong, C. P. C.; Bourque, R. F. & Baxi, C. B.
Partner: UNT Libraries Government Documents Department

Performance Evaluation for Modular, Scalable Overhead Cooling Systems In Data Centers

Description: Scientific and enterprise data centers, IT equipment product development, and research data center laboratories typically require continuous cooling to control inlet air temperatures within recommended operating levels for the IT equipment. The consolidation and higher density aggregation of slim computing, storage and networking hardware has resulted in higher power density than what the raised-floor system design, coupled with commonly used computer rack air conditioning (CRAC) units, was originally conceived to handle. Many existing data centers and newly constructed data centers adopt CRAC units, which inherently handle heat transfer within data centers via air as the heat transfer media. This results in energy performance of the ventilation and cooling systems being less than optimal. Understanding the current trends toward higher power density in IT computing, more and more IT equipment manufacturers are designing their equipment to operate in 'conventional' data center environments, while considering provisions of alternative cooling solutions to either their equipment or supplemental cooling in rack or row systems. Naturally, the trend toward higher power density resulting from current and future generations of servers has, in the meanwhile, created significant opportunities for precision cooling suppliers to engineer and manufacture packaged modular and scalable systems. The modular and scalable cooling systems aim at significantly improving efficiency while addressing the thermal challenges, improving reliability, and allowing for future needs and growth. Such pre-engineered and manufactured systems may be a significant improvement over current design; however, without an energy efficiency focus, their applications could also lead to even lower energy efficiencies in the overall data center infrastructure. The overall goal of the project supported by California Energy Commission was to characterize four commercially available, modular cooling systems installed in a data center. Such modular cooling systems are all scalable localized units, and will be evaluated in terms of their operating energy efficiency ...
Date: May 1, 2009
Creator: Xu, TengFang T.
Partner: UNT Libraries Government Documents Department

Design window calculations for a constant q' lithium blanket comparing lithium and sodium coolants

Description: In previous work, a design window approach has been applied to a liquid metal cooled, stagnant lithium breeding blanket, where the cooling tubes are spaced such that they all have the same heat flux per unit length (constant q'). This report is partly supplemental in that is is a detailed clarification of the equations and assumptions used, including several refinements. However, it also includes documentation for a revised version of the WINDOW code used to generate the design windows, and (as an example of the usefulness of the design window approach) a comparison of lithium cooling to sodium cooling of this blanket. The results confirm the desirability of lithium as a coolant.
Date: August 1, 1979
Creator: Gierszewski, P.; Mikic, B. & Todreas, N.
Partner: UNT Libraries Government Documents Department

Degradation of desiccants upon contamination: An experimental study

Description: Experiments were conducted to quantify the effects of thermal cycling and exposure to contamination on solid desiccant materials that may be used in desiccant cooling systems. A test apparatus was used to thermally cycle several desiccant samples and expose them to ambient or contaminated humid air. The source of contamination was cigarette smoke. Six different solid desiccants were tested: two types of silica gel, activated alumina, activated carbon, molecular sieves, and lithium chloride. The exposed desiccant samples were removed after 0.5, 1, 2, 4, or 11 months of exposure and their moisture capacities were measured. Other tests were conducted to characterize pollutants deposited on the exposed samples or to evaluate impact of exposure on internal structure of the samples. Compared to fresh samples, the capacity loss due to thermal cycling with ambient air was generally 10% to 30%. The capacity loss due to only cigarette smoke was generally between 20% to 50%. 7 refs., 8 figs., 3 tabs.
Date: November 1, 1990
Creator: Pesaran, A.A.
Partner: UNT Libraries Government Documents Department

Low-noise control valve. II

Description: There was a concern the sliding gate portion of the control valve may damage the ends of the small bore tubes used in the body of the valve. This concern prompted removal of the valve for inspection after a few months of operation. The inspection revealed a fair percentage of closed and partially closed tubes, caused by galling when the gate, which was in contact with the tube ends due to the 130 psi pressure drop through the valve, traversed across the face of the tube bundle. The tubes were repaired by machining the end of the bundle just enough to open all tubes. A ''rolling'' gate, mentioned previously as being in the design stage, was completed and installed on the valve. Here, the design and operation of this unique rolling closure is described and illustrated. The use of this type closure results in no damage to tube ends, reduced operator size, and smooth trouble free operation.
Date: October 1, 1977
Creator: Christie, R.S.
Partner: UNT Libraries Government Documents Department