Determination of the hydrodynamic parameters of a reactor circulation system with lead-bismuth coolant under test conditions when there is a change in the power and revolutions of the main circulation pumps

Atomic Energy ◽  
1998 ◽  
Vol 85 (6) ◽  
pp. 903-906
Author(s):  
E. V. Golub ◽  
I. M. Kurbatov
Keyword(s):  
Circulation System ◽  
Hydrodynamic Parameters ◽  
Test Conditions ◽  
Main Circulation

INFLUENCE OF HEAT TREATMENT OF MOUNTAIN MASSIVE ON TEMPERATURE MODE OF GEOTHERMAL CIRCULATION SYSTEM

2018 ◽  
pp. 44-50
Author(s):  
Yu. P. Morozov
Keyword(s):  
Heat Transfer ◽  
Operating Time ◽  
Fluid Motion ◽  
Coolant Temperature ◽  
Circulation System ◽  
Thermal Processes ◽  
Temperature Mode ◽  
Heat Influx ◽  
Stationary Heat Transfer

Based on the solution of the problem of non-stationary heat transfer during fluid motion in underground permeable layers, dependence was obtained to determine the operating time of the geothermal circulation system in the regime of constant and falling temperatures. It has been established that for a thickness of the layer H <4 m, the influence of heat influxes at = 0.99 and = 0.5 is practically the same, but for a thickness of the layer H> 5 m, the influence of heat inflows depends significantly on temperature. At a thickness of the permeable formation H> 20 m, the heat transfer at = 0.99 has virtually no effect on the thermal processes in the permeable formation, but at = 0.5 the heat influx, depending on the speed of movement, can be from 50 to 90%. Only at H> 50 m, the effect of heat influx significantly decreases and amounts, depending on the filtration rate, from 50 to 10%. The thermal effect of the rock mass with its thickness of more than 10 m, the distance between the discharge circuit and operation, as well as the speed of the coolant have almost no effect on the determination of the operating time of the GCS in constant temperature mode. During operation of the GCS at a dimensionless coolant temperature = 0.5, the velocity of the coolant is significant. With an increase in the speed of the coolant in two times, the error changes by 1.5 times.

scholarly journals Applying the method of plane sections for evaluating the parameters of flight vehicles under multiphase flow

2020 ◽  
pp. 48-61
Author(s):  
V. I. Pegov ◽  
◽  
I. Yu. Moshkin ◽  
Keyword(s):  
Experimental Data ◽  
Multiphase Flow ◽  
Flight Vehicle ◽  
Hydrodynamic Problem ◽  
Validation And Verification ◽  
Hydrodynamic Parameters ◽  
Flight Vehicles ◽  
Linear Load ◽  
Gas Cavity

Numerical simulation of the underwater motion of flight vehicles launched from underwater is performed. The updated method of plane sections is used to determine the hydrodynamic parameters of flight vehicles under multiphase flow. Hydrodynamic loading can be evaluated through the determination of nonstationary boundaries of a gas cavity and the linear load on the water-flown aft. By the method of plane sections, the 3D boundary value problem of the cavitational flow of a flight vehicle at an attack angle resolves itself into a plane hydrodynamic problem, separate for each section of the cavity. The predicted results are compared with the experimental data. Validation and verification were performed by comparing the analysis results with the experimental data. The applicability of the method of plane sections to the determination of the hydrodynamic parameters of flight vehicles under multiphase flow is demonstrated.

A Note on the Determination of the Drag of Retractable Undercarriages in Flight

1940 ◽  
Vol 44 (360) ◽  
pp. 862-864
Author(s):  
J. A. C. Williams
Keyword(s):  
Usual Method ◽  
Flight Tests ◽  
Level Flight ◽  
Test Conditions ◽  
The Difference

Upon occasion it is required to find the drag of aircraft components which are normally retracted in level flight, such as flaps and undercarriages. The usual method of obtaining this drag from flight tests, is to measure speeds in level flight under known engine conditions with the component retracted and then with the component down. The difference of speed so obtained, together with the known test conditions then yields an answer. The disadvantage of this method is that, as the difference of speed is usually large, incidence changes and airscrew and engine assumptions cause discrepancies in the results. The difference of power between different engines of a type can be ± 5 per cent. A method is proposed which will enable most of the disadvantages of the older method to be overcome.

Determination of the Content of Ultra-Low Sulphur in PM Superalloy FGH96 by Infrared Carbon-Sulphur Detector

2013 ◽  
Vol 634-638 ◽  
pp. 1821-1825
Author(s):  
Jian Huan Wei ◽  
Wei Cao ◽  
Yong Zhang
Keyword(s):  
Grain Boundary ◽  
Fatigue Property ◽  
Market Demand ◽  
Analysis Techniques ◽  
Test Conditions ◽  
Turbine Disc ◽  
Quantity Control ◽  
Impurity Elements ◽  
Pm Superalloy

PM Superalloy FGH96 is usually used as turbine disc materials. It is a kind of alloy with high purity, which has strict demands of the content of impurity elements, especially the element of sulphur. Because sulphur is accumulated in the grain boundary of manganese or iron, with the form of sulfide, it has great impact on the performance of PM Superalloy FGH96, such as toughness and fatigue property. Therefore, it is an important part of quantity control to detect accurately of the content of ultra-low sulphur in PM Superalloy FGH96. As the market demand of PM Superalloy FGH96 and quality becomes varied, it is a trend that PM Superalloy FGH96 has ultra-low content of sulphur (S: 0.0001%-0.0020%). Hence, the related analysis techniques are needed. A new method of analyzing Ultra-low Sulphur (S: 0.0001%-0.0020%) in PM Superalloy FGH96 is established in the article by selective experiments with relevant test conditions, such as combustion conditions and blank test, using infrared carbon-sulphur detector.

A method of high sensitivity and in situ determination of trace cobalt(II) in water samples with salicyl fluorone

2014 ◽  
Vol 70 (7) ◽  
pp. 1182-1187 ◽  
Author(s):  
Zhe Chen ◽  
Hua Li
Keyword(s):  
Flow Injection ◽  
Water Samples ◽  
High Sensitivity ◽  
Basic Solution ◽  
Optimum Conditions ◽  
Cetylpyridinium Bromide ◽  
Test Conditions ◽  
Relative Standard

Based on the sensitive reaction of Co(II) and salicyl fluorone with the presence of cetylpyridinium bromide in basic solution, a new method of flow injection micelle-solubilized spectrophotometry was developed for the determination of cobalt. The reaction was monitored for the absorbance of Co(II) at 540 nm. The reagents, flow injection variables and effects of foreign ions were investigated and the optimum conditions were established. At the optimum test conditions, the developed method provides a linearity range of 3–40 μg L−1 with a detection limit of 0.1 μg L−1 at about 60 h−1 sampling frequency. Relative standard deviation of 0.91, 0.95 and 0.89% were obtained for the determination of 3, 15 and 30 μg L−1 Co(II) solution. The proposed method has been successfully applied for analysis of trace amounts of cobalt in water samples.

Determination of Hydrodynamic Parameters for Remotely Operated Vehicles

2016 ◽  
Author(s):  
Ole A. Eidsvik ◽  
Ingrid Schjølberg
Keyword(s):  
Numerical Simulations ◽  
Degrees Of Freedom ◽  
Analytical Data ◽  
Relative Difference ◽  
Accurate Estimate ◽  
Six Degrees Of Freedom ◽  
Hydrodynamic Parameters ◽  
Planar Motion Mechanism ◽  
Rotational Degrees Of Freedom

In this paper the hydrodynamic parameters that characterize the behavior of a typical unmanned underwater vehicle are evaluated. A complete method for identifying these parameters is described. The method is developed to give a brief and accurate estimate of these parameters in all six degrees of freedom using basic properties of the vehicle such as dimensions, mass and shape. The method is based on both empirical and analytical results for typical reference geometries (ellipsoids, cubes, etc.). The method is developed to be applicable for a wide variety of UUV designs as these typically varies substantially. The method is then applied to a small observation class ROV. The results are first verified using an experimental method in which the full scale ROV is towed using a planar motion mechanism. An additional verification is performed with numerical simulations using Computational Fluid Dynamics and a radiation/diffraction program. The method shows promising results for both damping and added mass for the tested case. The translational degrees of freedom are more accurate than the rotational degrees of freedom which are expected as most empirical and analytical data are for translational degrees of freedom. The case study also reveals that the relative difference between the numerical simulations and the experimental results are similar to the relative difference between the proposed method and the experiment.

Estimation of Measurement Upper Limit in Deriving the Vibration Environmental Test Conditions by Bootstrap Method

2012 ◽  
Vol 566 ◽  
pp. 11-14
Author(s):  
Jian Jun Zhang ◽  
Jian Yong Sun ◽  
Ming Li ◽  
Hai Juan Chang
Keyword(s):  
Bootstrap Method ◽  
Small Sample ◽  
Measure Data ◽  
Test Conditions ◽  
Power Spectral ◽  
Upper Limits ◽  
Environmental Test ◽  
Upper Tolerance Limit ◽  
Field Measure

For deriving the vibration environmental test conditions of materiels in the limited field measured data, a bootstrap method is firstly employed to evaluate the upper tolerance limit of the vibration power spectral density (PSD). Firstly for the simulation data from the normal distribution, the bias-corrected bootstrap method and the bootstrap-t method are validated to attain the appropriate upper limits for the small sample data through comparing the evaluations with the true values. Secondly for the 10 and 90 flight measurements of some aircraft, the upper tolerance limits of vibration PSD have been estimated by the above method and the traditional computation methods of MIL-STD-810F and GJB126. The result shows the bootstrap method fits the actual vibration environment better than other two methods and it has a wide application in the determination of vibration test conditions based on the small field measure data.

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