Aeronautical engineering: A special bibliography with indexes, supplement 82, April 1977

This bibliography lists 311 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1977

Aeronautical Engineering: A special bibliography, supplement 60

This bibliography lists 284 reports, articles, and other documents introduced into the NASA scientific and technical information system in July 1975

CFD Modeling of Globe Valves for Oxygen Application

Components used in high-pressure, high-temperature, flowing oxygen are susceptible to ignition and combustion in presence of restriction or when particles impact these restriction. The valves in any systems are the common flow restrictors, hence, the design and analyses of valves are most critical tasks. The flow of oxygen through valves distinguishes itself by accentuating auto-ignition and consequent flame propagation in metals and non-metals, apart from other usual characteristics present with gases/liquids. The combination of ignition resistance, proper and reliable performance and fabrication economy marks the specification of material and design of valves in oxygen-enriched environment. The analyses have been performed by applying the commercial computational fluid dynamics (CFD) code, FLUENT, to obtain the solution of the two-dimensional turbulent flow field through a globe valve for its different openings in the GOX environment. The flow control valves in high velocity oxygen systems for different openings are simulated for turbulence and eddy dissipation. The influence of pressure, flow rate and opening of the valve on the rise in temperature and eddy dissipation rate is also obtained for compressible flow range. The simulation for turbulence is done by k- and k- turbulence models and the results have been compared

An Overview of EGS Development and Management Suggestions

The world is facing the energy challenge to over-reliance to fossil-fuels, the development of renewable energy is inevitable. From a clean and economic view, enhanced geothermal system (EGS) provides an effective mean to utilize geothermal energy to generate. Different form the conventionalhydro geothermal, the host rock of EGS is Hot Dry Rock (HDR), which buries deeper with high temperature (more than 180°C). The generationof EGS is promising. The development of EGS can be combined with the tech Power to geothermal energy. Exceed power is supposed to drive fluid working in HDR layer to obtain geothermal energy for generation. The whole article can be divided into three parts. In the first art, evaluation indexes of EGS as well as pilot EGs Projects (e.g. Fenton Hill and Basel) and exiting EGS project (e.g. Paralana and Newberry) are summarized, which points a general impression on EGS site. The dominate indexes are heat flow, geothermal gradient and thermal storage. The second part is focused on the simulation methods and working fluids selection of EGS. A detailed comparison of the main simulation software (e.g. TOUGH2 and FEHM) is carried out. With the respect of working fluid selection, the comparison between water and CO2 is researched and CO2 is a preferred option for EGS development for less fluid loss and less dissolution to HDR. The art of CO2-EGS is introduced clearly in this part. The third part is about the addition consideration of EGS plant operation, it excludes auxiliary plant support and HSE management

Index to NASA Tech Briefs, 1975

This index contains abstracts and four indexes--subject, personal author, originating Center, and Tech Brief number--for 1975 Tech Briefs

Aeronautical Engineering: A special bibliography with indexes, supplement 62

This bibliography lists 306 reports, articles, and other documents introduced into the NASA scientific and technical information system in September 1975

Aeronautical Engineering: A special bibliography with indexes, supplement 54

This bibliography lists 316 reports, articles, and other documents introduced into the NASA scientific and technical information system in January 1975

Development of Advanced High Temperature Heat Exchangers: Proposal

A research team led by the University of Nevada, Las Vegas (UNLV) Research Foundation proposes a project to develop advanced high temperature heat exchangers (HTHX) for hydrogen production and electrical energy conversion from advanced nuclear reactor concepts. This project will also support the development of Generation IV reactors. The research team includes researchers from UNLV, General Atomics (GA), Sandia National Laboratories (SNL), The University of California, Berkeley UCB) and Oak Ridge National Laboratory (ORNL). The proposed project will be administered by the University of Nevada Las Vegas Research Foundation (UNLVRF). UNLVRF will provide the overall contract administration and is the funding entity. Activities will include planning, budget and schedule reporting, collecting and organizing technical reports and team reviews. Quarterly progress reports will be delivered to DOE, including schedule and budget status. Review meetings will include a kick-off meeting and periodic meetings of the team. Other project management functions will include subcontracting and contracting as required and management and coordination of deliverables and schedules

Synthetic Esters in Hydraulic Valves

Each year 35-37 million tons of lubrication is consumed. Hydraulic oils constitute 10.2% of the total lubrication consumption, and a large part of that is lost to leakage, hose burst and accidents. One way of reducing the pollution caused by hydraulic oil lost in nature is to replace the standard mineral oil with an environmentally acceptable oil, EAL. EALs are already being used but to an extent, that is somewhat sector dependant, and reluctance amongst system designers is one of the factors limiting the usage. Hydraulic experts and end-users say, that two of the main obstacles are the lack of knowledge and the fear of technical problems. The objective of this project is to map the current knowledge on EAL with a focus on synthetic esters, HEES, and build on the lesser-known topics. A state of the art on synthetic ester is made, which shows, the influence of HEES on several components is poorly covered by current research. Two of the most commonly used valves in hydraulics is selected for studies: The pressure compensated directional control valve, PCPDCV, and the counterbalance valve, CBV. The PCPDCV study focuses on characterizing dynamics valve response using frequency responses to fit linear models of 2nd and 3rd order. The CBV studies focus on describing the steady-state valve behaviour using CFD while identifying fluid dynamics and friction. Experiments have been performed supporting the model work in the studies. Standard mineral oil with improved viscosity/temperature properties, HV, was used for reference, along with a partially saturated synthetic ester and a fully saturated synthetic ester. During experiments with the three oil types, valve behaviour with synthetic ester has been observed, included in the models and compared to the reference oil. Experiments were run at 20C-60C resulting in a benchmark targeting actual system design, where temperature, in general, cannot be assumed constant. The changes in steady-state fluid dynamics, when comparing HEES to HV, were found to be insignificant by investigating steady-state CBV behaviour. The conclusion is based on estimates of the main discharge coefficient and the flow force found using CFD. The steady-state friction identified differed significantly between both HEES and HV but also between saturated and partially saturated HEES oils. The strong link between hysteresis and friction in the CBV experiments allows for an evaluation of friction difference between oil types. The friction was up to 42% less for the fully saturated HEES and up to 20% higher for the partially saturated HEES. The friction of the CBV valve is known to be heavily influenced by its dynamic seals and it should be noted the seals were of the FPM type. HEES was observed to have some influence on PCPDCV valve dynamics mainly at lower temperatures. The two PCPDCV valves investigated had different reactions to oil type. Almost no oil type dependency was observed for the open-loop controlled HAWE valve, while the closed-loop position-controlled Danfoss valve saw up to 28% reduction in bandwidth and an increase in the rise time of up to 18%. The reduction in bandwidth happened when using fully saturated HEES, but using partially saturated HEES resulted in a similar or faster valve. The reduction in bandwidth and increase in the rise time were most pronounced at low temperature (20C) and are less likely to be an issue at higher temperatures.publishedVersio

Applications of aerospace technology to petroleum extraction and reservoir engineering

Through contacts with the petroleum industry, the petroleum service industry, universities and government agencies, important petroleum extraction problems were identified. For each problem, areas of aerospace technology that might aid in its solution were also identified, where possible. Some of the problems were selected for further consideration. Work on these problems led to the formulation of specific concepts as candidate for development. Each concept is addressed to the solution of specific extraction problems and makes use of specific areas of aerospace technology