Steam Explosion Experiments Using ZrO2 and ZrO2/UO2 Mixture

2002 ◽  
Author(s):  
Jinho Song ◽  
Ikkyu Park ◽  
Yongseung Sin ◽  
Jonghwan Kim ◽  
Seongwan Hong ◽  
...  
Keyword(s):  
Steam Explosion ◽  
Static Pressure ◽  
Dynamic Pressure ◽  
Pressure Profile ◽  
Conversion Ratio ◽  
Water Pool ◽  
Energy Research ◽  
Melt Temperature ◽  
Water Interaction ◽  
Made In

Korea Atomic Energy Research Institute (KAERI) has been carrying an experimental research program on the steam explosion named “Test for Real cOrium Interaction with water (TROI)” since 1997. The objective of the program is to investigate whether the corium would lead to an energetic steam explosion and to measure the conversion ratio of the energetic steam explosion. In the first series of tests using several kg of ZrO2 where the melt/water interaction were made in the water pool at 30 ∼ 95 °C, either a quenching or a spontaneous steam explosions was observed. In the second series of tests using the mixture of UO2/ZrO2 performed in a similar manner as that of ZrO2, it also resulted in either a quenching or energetic steam explosion. The morphology of debris and pressure profile clearly indicate the differences in those two phenomena. The process parameters including the dynamic pressure, dynamic impulse, water and melt temperature, static pressure inside the containment chamber were measured.

The Influence of Low Solidity Vaned Diffusers on the Static Pressure Non-Uniformity Caused by a Centrifugal Compressor Discharge Volute

2000 ◽  
Author(s):  
James M. Sorokes ◽  
Jay M. Koch
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Centrifugal Compressor ◽  
Static Pressure ◽  
Dynamic Pressure ◽  
Pressure Profile ◽  
Vaneless Diffusers ◽  
Discharge Pressure ◽  
Dynamics Analyses ◽  
Work Done

The paper is a sequel to an earlier work by Sorokes et al. 1998, “Investigation of the Circumferential Static Pressure Non-Uniformity Caused by a Centrifugal Compressor Discharge Volute.” The earlier work described experimental and computational fluid dynamics analyses of the non-uniform static pressure distortion caused by the discharge volute in a high pressure, centrifugal compressor with vaneless diffusers. This paper describes additional testing and analytical work done using low solidity vaned diffusers (LSD’s) in place of select vaneless diffusers to determine the alternate diffuser’s effectiveness in eliminating or reducing the magnitude of the non-uniform pressure field. As in the earlier studies, the experiments described in this paper were done using a heavily instrumented gas re-injection compressor operating at over 6000 psia discharge pressure. Instrumentation was installed to measure static, total, and dynamic pressure as well as impeller strain and mechanical vibrations. A brief description of the compressor and instrumentation are provided. Concurrent with the experimental work, CFD runs were completed to study the effect of the alternate vaned diffusers. The CFD pressure profile trends agreed well with the experimental results and provided analytical corroboration for the conclusions drawn from the test data. Conclusions are drawn regarding: a) the effectiveness of the LSD’s on the pressure non-uniformity; b) the associated effects on the measured dynamic strains in the impellers; and c) the usefulness of computational fluid dynamics (CFD) in assessing the aerodynamic forces associated with the non-uniformity.

Investigation of the Circumferential Static Pressure Non-Uniformity Caused by a Centrifugal Compressor Discharge Volute

1998 ◽  
Author(s):  
James M. Sorokes ◽  
Cyril J. Borer ◽  
Jay M. Koch
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Pressure ◽  
Centrifugal Compressor ◽  
Static Pressure ◽  
Dynamic Pressure ◽  
Pressure Profile ◽  
Mechanical Vibrations ◽  
Flow Rates ◽  
Dynamics Analyses

The paper describes experimental and computational fluid dynamics analyses of the non-uniform static pressure distortion caused by the discharge volute in a high pressure, centrifugal compressor. The experiments described in this paper were done using a heavily instrumented gas re-injection compressor operating at over 6000 psia discharge. Instrumentation was installed to measure static, total, and dynamic pressure as well as impeller strain and mechanical vibrations. A brief description of the compressor and instrumentation are provided. Concurrent with the experimental work, CFD runs were completed to study the reasons for the pressure non-uniformity. The CFD pressure profile trends agreed well with the experimental results and provided analytical corroboration for the conclusions drawn from the test data. Conclusions are drawn regarding: a) the response of the non-uniformity to changing flow rates; b) the extent to which the non-uniformity can be detected upstream of the impeller; and c) the mechanical influences of the non-uniformity on the impellers.

scholarly journals The pressure distribution on the head of a shell moving at high velocities

1920 ◽  
Vol 97 (684) ◽  
pp. 202-218 ◽  
Keyword(s):  
Relative Motion ◽  
Static Pressure ◽  
Dynamic Pressure ◽  
National Physical Laboratory ◽  
The Body ◽  
Physical Laboratory ◽  
University College London ◽  
General Scientific ◽  
Axis Of Symmetry ◽  
Made In

The pressure at any point of a body moving through a fluid may be considered to consist of two components — the static pressure , which would be the pressure at that point, if there were no relative motion between the body and the fluid—and the dynamic pressure due to the relative motion. The sum may be called the total pressure at the point, and is, of course, always positive; the dynamic pressure alone may be negative. Experiments, of an introductory kind, were undertaken by the authors, at the request of the Ordnance Committee, to attempt to determine, as a function of the velocity of the shell, the dynamic pressure at various points on the head of a shell, whose axis of symmetry and direction of motion coincide or nearly coincide. The results appear to be not without general scientific interest, and are therefore presented in this paper by permission of the Ordnance Committee. The authors’ best thanks are due to the officers of the Experimental Department, H. M. S. “Excellent,” on whose range the firing trial was carried out; to the other officers of the Munitions Inventions Department, who shared the work of observation and computation; to the Director of the National Physical Laboratory, where the comparative observations at low velocities were made in a wind channel; and, above all, to Mr. W. J. Goudie, of University College, London, on whose determinations of the rates of burning of powder-train time-fuzes at high rotational speeds the whole experiment was based.

The Steam Explosion Induced by the Molten Reactor Material-Water Interaction

2002 ◽  
Author(s):  
J. H. Song ◽  
I. K. Park ◽  
Yongseung Shin ◽  
J. H. Kim ◽  
S.W. Hong ◽  
...  
Keyword(s):  
Steam Explosion ◽  
Reactor Material ◽  
Water Interaction

scholarly journals Computational Modeling of Flow Characteristics in Three Products Hydrocyclone Screen

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1295
Author(s):  
Anghong Yu ◽  
Chuanzhen Wang ◽  
Haizeng Liu ◽  
Md. Shakhaoath Khan
Keyword(s):  
Static Pressure ◽  
Cfd Simulation ◽  
Volume Fraction ◽  
Flow Characteristics ◽  
Pressure Profile ◽  
Reynolds Stress Model ◽  
Grid Scheme ◽  
Cylindrical Screen ◽  
The Right ◽  
Axial Depth

Three products hydrocyclone screen (TPHS) can be considered as the combination of a conventional hydrocyclone and a cylindrical screen. In this device, particles are separated based on size under the centrifugal classification coupling screening effect. The objective of this work is to explore the characteristics of fluid flow in TPHS using the computational fluid dynamics (CFD) simulation. The 2 million grid scheme, volume fraction model, and linear pressure–strain Reynolds stress model were utilized to generate the economical grid-independence solution. The pressure profile reveals that the distribution of static pressure was axisymmetric, and its value was reduced with the increasing axial depth. The maximum and minimum were located near the tangential inflection point of the feed inlet and the outlets, respectively. However, local asymmetry was created by the left tangential inlet and the right screen underflow outlet. Furthermore, at the same axial height, the static pressure gradually decreased along the wall to the center. Near the cylindrical screen, the pressure difference between the inside and the outside cylindrical screen dropped from positive to negative as the axial depth increased from −35 to −185 mm. Besides, TPHS shows similar distributions of turbulence intensity I, turbulence kinetic energy k, and turbulence dissipation rate ε; i.e., the values fell with the decrease in axial height. Meanwhile, from high to low, the pressure values are distributed in the feed chamber, the cylindrical screen, and conical vessel; the value inside the screen was higher than the outer value.

Static pressure distribution in the free turbulent jet

1957 ◽  
Vol 3 (1) ◽  
pp. 1-16 ◽  
Author(s):  
David R. Miller ◽  
Edward W. Comings
Keyword(s):  
Static Pressure ◽  
Longitudinal Velocity ◽  
Fluid Motion ◽  
Mean Velocity ◽  
Free Jet ◽  
Static Pressure Distribution ◽  
Two Dimensional Flow ◽  
The Common ◽  
Jet Theory ◽  
Made In

Measurements of mean velocity, turbulent stress and static pressure were made in the mixing region of a jet of air issuing from a slot nozzle into still air. The velocity was low and the two-dimensional flow was effectively incompressible. The results are examined in terms of the unsimplified equations of fluid motion, and comparisons are drawn with the common assumptions and simplifications of free jet theory. Appreciable deviations from isobaric conditions exist and the deviations are closely related to the local turbulent stresses. Negative static pressures were encountered everywhere in the mixing field except in the potential wedge region immediately adjacent to the nozzle. Lateral profiles of mean longitudinal velocity conformed closely to an error curve at all stations further than 7 slot widths from the nozzle mouth. An asymptotic approach to complete self-preservation of the flow was observed.

scholarly journals Dynamic Pressure Pain Hypersensitivity as Assessed by Roller Pressure Algometry in Episodic Cluster Headache

2020 ◽  
Vol 2;23 (4;2) ◽  
pp. 219-227
Author(s):  
César Fernández-de-las-Peñas
Keyword(s):  
Cluster Headache ◽  
Pain Sensitivity ◽  
Static Pressure ◽  
Dynamic Pressure ◽  
Pressure Algometry ◽  
Pressure Pain ◽  
Key Words Cluster Headache ◽  
Pressure Pain Thresholds ◽  
Preventive Medication ◽  
Pressure Algometer

Background: A method for assessing dynamic muscle hyperalgesia (dynamic pressure algometry) has been developed and applied in tension-type and migraine headaches. Objectives: To investigate differences in dynamic pressure pain assessment over the trigeminal area between men with cluster headache (CH) and headache-free controls, and the association between dynamic and static pressure pain sensitivity. Study Design: A case-control study. Setting: Tertiary urban hospital. Methods: Forty men with episodic CH and 40 matched controls participated. Dynamic pressure pain sensitivity was assessed with a dynamic pressure algometry set consisting of 8 rollers with different fixed levels (500, 700, 850, 1,350, 1,550, 2,200, 3,850, and 5,300 g). Each roller was moved at a speed of 0.5 cm/sec over a diagonal line covering the temporalis muscle from an anterior to posterior direction. The dynamic pressure threshold (DPT; load level of the first painful roller) and the pain intensity perceived at the DPT level (roller-evoked pain) were assessed. Static pressure pain thresholds (PPT) were also assessed with a digital pressure algometer applied statically over the mid-muscle belly of the temporalis. Patients were assessed in a remission phase, at least 3 months from the last cluster attack, and without preventive medication. Results: Side-to-side consistency between DPTs (r = 0.781, P < 0.001), roller-evoked pain on DPT (r = 0.586; P < 0.001), and PPTs (r = 0.874; P < 0.001) were found in men with CH. DPT was moderately, bilaterally, and side-to-side associated with PPTs (0.663 > r > 0.793, all P < 0.001). Men with CH had bilateral lower DPT and PPT and reported higher levels of rollerevoked pain (all P < 0.001) than headache-free controls. Limitations: Only men with episodic CH were included. Conclusions: This study supports that a dynamic pressure algometry is as valid as a static pressure algometry for assessing pressure pain sensitivity in patients with CH. Assessing both dynamic and static pain sensitivity may provide new opportunities for differentiated diagnostics. Key words: Cluster headache, dynamic pressure pain, pressure pain threshold

scholarly journals Modelling of water jet impact on molten metal

2021 ◽  
Vol 2119 (1) ◽  
pp. 012073
Author(s):  
S E Yakush ◽  
N S Sivakov ◽  
V I Melikhov ◽  
O I Melikhov
Keyword(s):  
Steam Explosion ◽  
Water Jet ◽  
Point Of View ◽  
Change Model ◽  
Water Pool ◽  
Jet Impact ◽  
Melt Water ◽  
Height Dependence ◽  
The Impact ◽  
Primary Melt

Abstract Splashes of high-temperature melt spreading over a water pool bottom can be a reason for the formation of a zone where melt, water and steam are mixed, providing conditions for powerful steam explosions. The paper considers the formation of melt splashes arising from the impact of a water jet on the surface of the melt. Numerical simulations are performed in 3D formulation, using the VOF method and an improved phase change model. The evolution of melt surface following the water jet impact is demonstrated, including the formation of a cavern, a primary melt splash known as the crown, as well as a secondary splash following the collapse of the cavern, known as the cumulative jet. Parametric study for the melt splash height dependence on the water jet geometry and velocity is carried out. The results of numerical analysis are discussed from the point of view of the similarity with respect to the momentum and kinetic energy of water jet. The significance of the results for the steam explosion problem is discussed.

scholarly journals An Implanted Magnetic Microfluidic Pump for In Vivo Bone Remodeling Applications

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 300 ◽  
Author(s):  
Ziyu Chen ◽  
Sunggi Noh ◽  
Rhonda D. Prisby ◽  
Jeong-Bong Lee
Keyword(s):  
Bone Growth ◽  
Static Pressure ◽  
Dynamic Pressure ◽  
The Body ◽  
In Vivo Studies ◽  
Fischer 344 ◽  
Fischer 344 Rat ◽  
Pressure Modulation

Modulations of fluid flow inside the bone intramedullary cavity has been found to stimulate bone cellular activities and augment bone growth. However, study on the efficacy of the fluid modulation has been limited to external syringe pumps connected to the bone intramedullary cavity through the skin tubing. We report an implantable magnetic microfluidic pump which is suitable for in vivo studies in rodents. A compact microfluidic pump (22 mm diameter, 5 mm in thickness) with NdFeB magnets was fabricated in polydimethylsiloxane (PDMS) using a set of stainless-steel molds. An external actuator with a larger magnet was used to wirelessly actuate the magnetic microfluidic pump. The characterization of the static pressure of the microfluidic pump as a function of size of magnets was assessed. The dynamic pressure of the pump was also characterized to estimate the output of the pump. The magnetic microfluidic pump was implanted into the back of a Fischer-344 rat and connected to the intramedullary cavity of the femur using a tube. On-demand wireless magnetic operation using an actuator outside of the body was found to induce pressure modulation of up to 38 mmHg inside the femoral intramedullary cavity of the rat.

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