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A boundary layer injection method of controlling scale-buildup in geothermal two-phase flow nozzles is studied. The object of this study is to set an upper limit on the ratio of the injected mass flow rate to the free stream mass flow rate that is necessary to isolate the scale carrying free stream flow from the nozzle wall. In order to develop a numerical model of the boundary layer flow, assumptions are made which reduce the results to order of magnitude approximations. Two configurations of nozzles with various injection flow rates are tried. It is found by numerical experiment that a nozzle with injection through a 1 mm thick ring near the inlet, is more efficient at isolating the free stream than a porous nozzle. A mass flow rate ratio of 0.173% was necessary to achieve this effect. It may be concluded that an upper limit on the mass flow rate ratio is about 2.0% with injection through a ring near the inlet, and that boundary layer injection is a reasonable method of controlling scale-buildup. A glossary of variables, program documentation and listings are presented for programs GMD15SR8, TRACK11, and TRACK12.

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For the past two decades, programs have been conducted to develop ZrH reactor space power systems. Present development plans for reactor space system components are geared to the development of off-the-shelf standardized reactor components which can be used without modification in either Brayton, thermoelectric (TE), or organic Rankine power systems over a power range of 3 to 15 kW(e). In recent years, national energy programs have highlighted the need to increase production of oil and gas from domestic sources. The US oil and ocean engineering industries are developing subsea production methods and equipment for recovering petroleum from deep water and ice-covered regions. There is the need for a subsea power source for highly reliable, unattended operation. Preliminary studies indicate that ZrH reactor subsea power systems may offer advantages in deep water sites remote from surface support facilities, in regions of severe surface or icing conditions, and in areas of critical environmental problems. A number of major US oil companies have indicated a potential need for a subsea nuclear power system for future offshore operations and have expressed their interest in a concept based on the ZrH reactor and an organic Rankine power conversion system (PCS). Work pursued during FY 1975 …

The recovery by postirradiation annealing of the irradiation produced shift in the fracture toughness transition of A533-B was investigated. Irradiation embrittlement was reduced by 40% after annealing at 600/sup 0/F for material that had been irradiated to approximately 2 x 10/sup 19/ n/cm/sup 2/ at 550/sup 0/F.

General balance laws and constitutive relations are developed for convective hydrothermal geothermal reservoirs. A fully interacting rock-fluid system is considered; typical rock-fluid interactions involve momentum and energy transfer and the dependence of rock porosity and permeability upon the fluid and rock stresses. The mathematical model also includes multiphase (water/steam) effects. A simple analytical model is employed to study heat transfer into/or from a fluid moving in a porous medium. Numerical results show that for fluid velocities typical of geothermal systems (Reynolds number much less than 10), the fluid and the solid may be assumed to be in local thermal equilibrium. Mathematical formalism of Anderson and Jackson is utilized to derive a continuum species transport equation for flow in porous media; this method allows one to delineate, in a rigorous manner, the convective and diffusive mechanisms in the continuum representation of species transport. An existing computer program (QUAGMR) is applied to study upwelling of hot water from depth along a fault; the numerical results can be used to explain local temperature inversions occasionally observed in bore hole measurements.

Forty-nine citations are included most of which deal with geothermal subsidence. Other citations deal with subsidence caused by groundwater overdraft and oil and gas exploitation. Most of the entries have abstracts. A subject index, an author index, a list of references, and a glossary are included. (MHR)

Calculations and curves are presented which prove that for each turbine entry temperature, there is an entry pressure which will optimize the thermodynamic efficiency of a ''binary'' type geothermal power plant. Comparisons are made between thermodynamic efficiency and another method of rating process efficiency.

Results of this study indicates that the Salado Salt is composed primarily of fine to coarse-grained halite with polyhalite, anhydrite, and clay minerals. Other minerals detected in small amounts include gypsum, magnesite, quartz, feldspar, sylvite, carnallite, celestite(question), glauconite, and kainite(question). Petrographic evidence (hopper crystals, and intergrowth of halite with other minerals) indicate that the Salado Salt was deposited in rather shallow water and may have been exposed subaerially at times. There must have been a major change in environmental conditions between the deposition of the Castile Formation and that of the Salado. The evidence also suggests that fluids have been able to move through the Salado Salt along beds and seams of clay and silt and somewhat along fractures. Water loss upon heating to 102 +- 5/sup 0/C ranges from 0.0 to 3.5 percent, considerably lower than those for Lyons, Kansas samples. Most of the dehydration water at 100/sup 0/C comes from clay minerals, while at higher temperatures, polyhalite contributes. The rock units in Salado Salt seem to release much less water when dehydrated than the Hutchinson Salt rocks at Lyons. During preparation of some of the samples, H/sub 2/S and possibly some natural gas were released when the samples …

The results of a system weight, efficiency, and size analysis which was performed on the 500 W(e) low cost high performance generator (LCHPG) are presented. The analysis was performed in an attempt to improve system efficiency and specific power over those presented in June 1975, System Design Study Report TES-SNSO-3-25. Heat source volume, configuration, and safety as related to the 500 W(e) LCHPG are also discussed. (RCK)

Widely used constitutive laws for engineering materials assume plastic incompressibility and no effect on yield of the hydrostatic component of stress. However, void nucleation and growth (and thus bulk dilatancy) are commonly observed in some processes which are characterized by large local plastic flow, such as ductile fracture. The purpose of this work is to develop approximate yield criteria and flow rules for porous (dilatant) ductile materials, showing the role of hydrostatic stress in plastic yield and void growth. Other elements of a constitutive theory for porous ductile materials, such as void nucleation, plastic flow and hardening behavior, and a criterion for ductile fracture will be discussed in Part II. The yield criteria are approximated through an upper bound approach. Simplified physical models for ductile porous materials (aggregates of voids and ductile matrix) are employed, with the matrix material idealized as rigid-perfectly plastic and obeying the von Mises yield criterion. Velocity fields are developed for the matrix which conform to the macroscopic flow behavior of the bulk material. Using a distribution of macroscopic flow fields and working through a dissipation integral, upper bounds to the macroscopic stress fields required for yield are calculated. Their locus in stress space forms the …

A computational scheme is presented for the analysis of a certain class of problems involving creep of metals at elevated temperatures. The high temperature nonelastic behavior of materials is assumed to obey a new mechanical equation of state type constitutive relation recently proposed by Hart. As an illustration, the problem of creep of a closed-ended thick-walled cylinder under internal and external pressures is analyzed employing the proposed computational scheme and Hart's equation of state approach. Results are compared qualitatively with the results of classical strain hardening and time hardening theories of creep and the experimental results obtained earlier by other researchers. The proposed computational scheme is found to be very efficient from the view point of both computational time and effort. In regard to the equation of state approach, it is found that in addition to the general features of these classical creep theories, it is also capable of taking into account the effect of prior deformation history on subsequent creep behavior by simply specifying the initial distribution of a single state variable called hardness. (auth)

Data collected during studies of Onslow Bay, off the North Carolina coast during cruises during September, 1975, are reported. Current meters and thermography were placed at depths of 10 and 22 m along the 28 m isobath in the northeastern and southwestern sectors of the Bay. Data are included on wind turbulence and velocity; seawater salinity and temperature at various depths; the content of nitrates, phosphates, silicate, oxygen, chlorophyll, and phytoplankton biomass at various depths. Hydrographic and meteorologic conditions during the cruises are included. (CH)