Numerical Analysis on High Speed Liquid-Solid Impact of 17-4PH Material

2014 ◽  
Vol 548-549 ◽  
pp. 147-151
Author(s):  
Ming Li ◽  
Peng Fei Zhao ◽  
Guang Hui Wang ◽  
Jing Liu
Keyword(s):  
High Speed ◽  
Nuclear Power ◽  
Vertical Direction ◽  
Maximum Pressure ◽  
Solid Target ◽  
Initial Speed ◽  
Maximum Deformation ◽  
Impact Theory ◽  
Set Up ◽  
Symmetry Mode

In this paper, anaxis-symmetry mode is set up to simulate the high speed liquid-solid impact of 17-4ph material, which is widely used inwet steam turbine bladesof the nuclear power units. The initial speed of the droplet with the diameter of 0.3mm is 400m/s. The deformation of the solid and the stress distribution variation with time are obtained via numerical method. And the variation of the pressure inside the droplet and solid target has also been analyzed in detail. In this case, the maximum pressure in the vertical direction of the solid is 1099MPa, and the maximum deformation distance of the plateis 140nm. The results provide useful supplement and reference to the high-speed liquid-solid impact theory.

Experimental Study on the Interaction of Molten Sn With Water

2018 ◽  
Author(s):  
Longkun He ◽  
Pengfei Liu ◽  
Xisi Zhang ◽  
Wenjun Hu ◽  
Bo Kuang ◽  
...  
Keyword(s):  
Water Temperature ◽  
High Speed ◽  
Nuclear Power ◽  
Power Plants ◽  
Dynamic Pressure ◽  
Ambient Pressure ◽  
Influence Factors ◽  
Video Camera ◽  
Metallic Oxide ◽  
Set Up

In nuclear power plants, fuel-coolant interaction (FCI) often accompanied with core melt accidents, which may escalate to steam explosion destroying the integrity of structural components and even the containment under certain conditions. In the present study, a new facility for intermediate-scaled experiments named ‘Test for Interaction of MELt with Coolant’ (TIMELCO) has been set up to study FCI phenomena and thermal-hydraulic influence factors in metal or metallic oxide/water mixtures with melt at maximum 2750°C. The first series of tests was performed using 3kg of Sn which was heated to 800°Cand jetted into a column of 1m water depth (300mm in diameter) under 0.1MPa ambient pressure. The main changing parameter was water temperature, at 60 °C and 72 °C respectively. From the high-speed video camera, violent explosion phenomenon occurred at water temperature of 60°C, while no evident explosion observed at 72°C. The size of melt debris at 60°C is smaller than this at 72°C.On the contrary, the dynamic pressure at 60°C is larger. The results indicate that water temperature has an important effect on FCI and decreasing the temperature of the coolant is advantageous to the explosion.

scholarly journals Mechanical Properties of Polypropylene Warp-Knitted Hernia Repair Mesh with Different Pull Densities

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1322
Author(s):  
Wanli Xu ◽  
Pibo Ma ◽  
Gaoming Jiang ◽  
Ailan Wan
Keyword(s):  
Mechanical Properties ◽  
Tensile Stress ◽  
High Speed ◽  
Vertical Direction ◽  
Horizontal Stress ◽  
Raw Material ◽  
Knitted Fabrics ◽  
Polypropylene Monofilament ◽  
Set Up ◽  
Warp Knitted Fabric

The medical polypropylene monofilament with a diameter of 0.10 mm was used as the material. Four different pull densities and two different warp run-ins were set up on the electronic traverse high-speed Tricot warp knitting machine, with the gauge of E28. The raw material was used to knit four variations of single bar plain knitted fabrics with 1 in-1 miss setting. Each variation required eight samples. The mechanical properties of the above 32 warp-knitted fabric samples are tested, including their tensile stress (in both vertical and horizontal directions), tearing stress (in both vertical and horizontal directions) and bursting stress. The results obtained shows that the relationship between the vertical, the horizontal stress, and the pull density are not monotonic. The tensile stress in the vertical direction firstly decreases and then increases with an increase of the pull density; however, the tensile stress in the horizontal direction firstly increases and then slightly decreases with an increase of the pull density; again the vertical tensile stress of all fabrics was always higher than the horizontal tensile stress. The bursting stress has a positive linear relation to the pull density. The vertical tearing stresses of four samples were greater than the horizontal tearing stress.

Safety evaluation of buildings under flood impact

2021 ◽  
Author(s):  
Youtong Rong ◽  
Paul Bates ◽  
Jeffrey Neal
Keyword(s):  
Structural Damage ◽  
High Speed ◽  
Flow Direction ◽  
Interaction Model ◽  
Dam Break ◽  
Maximum Pressure ◽  
Two Phase ◽  
Maximum Deformation ◽  
Flood Impact ◽  
The Impact

<p>The flood caused by a dam-break event generally contains a large amount of energy, and it can be destructive to the downstream buildings and structures. An experiment-validated three-dimensional numerical model was designed to investigate the impact of dam-break flood on structures with different arrangements. The Eulerian two-phase flow model and the smooth particle dynamics method are applied separately to solve the flow motion, and  the deformation characteristics of buildings under the flood impact are evaluated by fluid-structure interaction model. An experiment is constructed to validate the numerical simulation. The results show that the structure suffers a large instantaneous impact pressure when the flood water first contacts the structure, and the value of this pressure can reach 1.5-3.0 times that of the maximum pressure after the first impact, and the maximum total pressure of the upstream building surface is about 1800N. The deformation near the door and windows is obvious, and the maximum deformation can reach 600μm, which further results in the large deformation of the gable and roof on both sides. Moreover, the arrangement of buildings has different blocking effect on flood. The back-row buildings arranged in alignment along the flow direction still has to bear 20% flood impact, and the front row buildings arranged alternately bear 90% high-speed flow impact. The structural damage is evaluated by the material failure criterion, and the weak position of buildings is identified, providing an optimal design of buildings.</p>

scholarly journals Stochastic Uncertainty in a Dam-Break Experiment with Varying Gate Speeds

2021 ◽  
Vol 9 (1) ◽  
pp. 67
Author(s):  
Hiroshi Takagi ◽  
Fumitaka Furukawa
Keyword(s):  
High Speed ◽  
Pressure Sensors ◽  
Dam Break ◽  
Maximum Pressure ◽  
Vertical Acceleration ◽  
Ship Wakes ◽  
Dam Break Flow ◽  
Statistical Relationships ◽  
Flow Propagation ◽  
Impulsive Pressure

Uncertainties inherent in gate-opening speeds are rarely studied in dam-break flow experiments due to the laborious experimental procedures required. For the stochastic analysis of these mechanisms, this study involved 290 flow tests performed in a dam-break flume via varying gate speeds between 0.20 and 2.50 m/s; four pressure sensors embedded in the flume bed recorded high-frequency bottom pressures. The obtained data were processed to determine the statistical relationships between gate speed and maximum pressure. The correlations between them were found to be particularly significant at the sensors nearest to the gate (Ch1) and farthest from the gate (Ch4), with a Pearson’s coefficient r of 0.671 and −0.524, respectively. The interquartile range (IQR) suggests that the statistical variability of maximum pressure is the largest at Ch1 and smallest at Ch4. When the gate is opened faster, a higher pressure with greater uncertainty occurs near the gate. However, both the pressure magnitude and the uncertainty decrease as the dam-break flow propagates downstream. The maximum pressure appears within long-period surge-pressure phases; however, instances considered as statistical outliers appear within short and impulsive pressure phases. A few unique phenomena, which could cause significant bottom pressure variability, were also identified through visual analyses using high-speed camera images. For example, an explosive water jet increases the vertical acceleration immediately after the gate is lifted, thereby retarding dam-break flow propagation. Owing to the existence of sidewalls, two edge waves were generated, which behaved similarly to ship wakes, causing a strong horizontal mixture of the water flow.

scholarly journals Analysis study the used of Tuned Mass Damper (TMD) on an existing train bridge due to high speed train with moving mass load approach

2019 ◽  
Vol 258 ◽  
pp. 05005 ◽  
Author(s):  
Wivia Octarena Nugroho ◽  
Dina Rubiana Widarda ◽  
Oryza Herdha Dwyana
Keyword(s):  
High Speed ◽  
Tuned Mass Damper ◽  
Dynamic Responses ◽  
Mass Ratio ◽  
High Speed Train ◽  
Maximum Deformation ◽  
Mass Load ◽  
Mass Damper ◽  
Existing Bridges ◽  
Comfort Criteria

As the need of the train speed increased, the existing bridges need to be evaluated, especially in dynamic responses, which are deformation and acceleration. In this study, Cisomang Bridge is modeled and analyzed due to the high-speed train SJ X2 in varying speeds, 50 km/h, 100 km/h, 150 km/h, and 200 km/h. The used of tuned mass damper also will be varied on its setting and placing. The tuned mass dampers setting be varied based on the first or second natural frequency and the placing of tuned mass damper be varied based on maximum deformation of the first or second mode. Moreover, the tuned mass damper ratio will be varied 1% and 1.6%. For all speed variations, dynamic responses of structure without TMD still fulfil the Indonesian Government Criterion based on PM 60 - 2012 but do not meet requirement of comfort criteria based on DIN-Fachbericht 101. Furthermore, only for the speed train 50km/h dynamic responses of structure fulfil safety criteria based on Eurocode EN 1990:2002, whereas the other speed variations do not meet that requirement. In the use of TMD 1% mass ratio, the structure fulfils the safety criteria for all speed variations. In the use of TMD 1.6% mass ratio, all the structure fulfils the safety and comfort criteria except 100 km/h speed which only fulfils the safety criteria.

Study on Magnetic Barrel Machine Equipped with Three-Dimensional Arrangement of Magnets

2007 ◽  
Vol 329 ◽  
pp. 761-766 ◽  
Author(s):  
Y. Zhang ◽  
Masato Yoshioka ◽  
Shin-Ichiro Hira
Keyword(s):  
High Speed ◽  
Permanent Magnets ◽  
Three Dimensional ◽  
Video Camera ◽  
High Speed Video ◽  
High Speed Video Camera ◽  
The Media ◽  
Set Up

At present, a commercially available magnetic barrel machine equipped with permanent magnets has some faults arising from constructional reason. That is, grinding or finishing ability is different from place to place in the machining region, resulting in the limitation on the region we can use in the container of workpieces. Therefore, in this research, authors made the new magnetic barrel machine equipped with three dimensional (3D) magnet arrangement to overcome these faults. The grinding ability of the new 3D magnetic barrel machine converted was experimentally examined, and compared with that of the traditional magnetic barrel machine. As a result, it was shown that we can use much broader region in the new 3D machine. It was also shown that the grinding ability became higher. The distribution of barrel media in action was recorded by means of a high speed video camera. It was clarified that the media rose up higher and were distributed more uniformly in the container by the effect of the magnet block newly set up. It was supposed that this must be the reason for the above-mentioned improvement of grinding ability.

Effect of Nanosized Filler on Matrix Dominated Properties of Fiber Reinforced Epoxy

2011 ◽  
Author(s):  
Yuanxin Zhou ◽  
Shaik Jeelani
Keyword(s):  
Compression Strength ◽  
High Speed ◽  
High Vacuum ◽  
Trapped Air ◽  
Nano Fiber ◽  
Open Hole ◽  
Set Up ◽  
Mechanical Agitator ◽  
Laminar Shear ◽  
Nanosized Filler

In this study, a high-intensity ultrasonic liquid processor was used to obtain a homogeneous molecular mixture of epoxy resin and carbon nano fiber. The carbon nano fibers were infused into the part A of SC-15 (diglycidylether of Bisphenol A) through sonic cavitations and then mixed with part B of SC-15 (cycloaliphatic amine hardener) using a high-speed mechanical agitator. The trapped air and reaction volatiles were removed from the mixture using high vacuum. Nanophased epoxy with 2 wt.% CNF was then utilized in a vacuum assisted resin transfer molding (VARTM) set up with carbon fabric to fabricate laminated composites. The effectiveness of CNF addition on matrix dominated properties of composites has been evaluated by compression, open hole compression and inter-laminar shear. The compression strength, open hole compression strength and ILS were improved by 21%, 23% and 15%, respectively as compared to the neat composite.

Leakage Flow Investigations on a Through-Wall Crack Related to Thermal Fatigue of Nuclear Power Plant Piping

2017 ◽  
Author(s):  
Stefan Schmid ◽  
Rudi Kulenovic ◽  
Eckart Laurien
Keyword(s):  
Experimental Data ◽  
Nuclear Power ◽  
Numerical Models ◽  
Measurement Techniques ◽  
Experimental Investigations ◽  
Leakage Flow ◽  
Test Rig ◽  
Reduced Pressure ◽  
Flow Rates ◽  
Set Up

For the validation of empirical models to calculate leakage flow rates in through-wall cracks of piping, reliable experimental data are essential. In this context, the Leakage Flow (LF) test rig was built up at the IKE for measurements of leakage flow rates with reduced pressure (maximum 1 MPA) and temperature (maximum 170 °C) compared to real plant conditions. The design of the test rig enables experimental investigations of through-wall cracks with different geometries and orientations by means of circular blank sheets with integrated cracks which are installed in the tubular test section of the test rig. In the paper, the experimental LF set-up and used measurement techniques are explained in detail. Furthermore, first leakage flow measurement results for one through-wall crack geometry and different imposed fluid pressures at ambient temperature conditions are presented and discussed. As an additional aspect the experimental data are used for the determination of the flow resistance of the investigated leak channel. Finally, the experimental results are compared with numerical results of WinLeck calculations to prove specifically in WinLeck implemented numerical models.

A Most Active Customer

2014 ◽  
Vol 44 (5) ◽  
pp. 470-502 ◽  
Author(s):  
Simone Turchetti
Keyword(s):  
World War Ii ◽  
Nuclear Power ◽  
Atomic Energy Commission ◽  
Developed Countries ◽  
Atomic Energy ◽  
Peace Treaty ◽  
Research Committee ◽  
Energy Field ◽  
Set Up ◽  
The U.S

After World War II had ended, Italy, not unlike other developed countries, held the ambition to establish an atomic energy program. The Peace Treaty of 1947 forbade its administration from seeking to acquire atomic weaponry, but in 1952 a national research committee was set up to explore the peaceful uses of atomic energy, in particular with regard to building nuclear reactors. One of the committee’s goals was to use nuclear power to make the country less reliant on foreign energy provisions. Yet, this paper reveals that the atomic energy project resulted in actually increasing Italy’s dependence on overseas assistance. I explain the reasons for this outcome by looking at the unfolding of U.S.–Italy relations and the offers of collaboration in the atomic energy field put forth by the U.S. State Department and the U.S. Atomic Energy Commission. I argue that these offers undermined plans to shape the nuclear program as its Italian architects had envisioned, caused them to reconsider the goal of self-sufficiency in energy provisioning, and reconfigured the project to be amenable to the security and economic priorities of the U.S. administration. In this way, I conclude, the path for the Italian project to “de-develop” was set.

Effect of Air Fraction on Force Coefficients in Oscillatory Flow

2021 ◽  
Author(s):  
Malene Hovgaard Vested ◽  
Erik Damgaard Christensen
Keyword(s):  
High Speed ◽  
Offshore Structures ◽  
Air Injection ◽  
Wave Loads ◽  
Morison Equation ◽  
Force Coefficients ◽  
Air Content ◽  
Set Up ◽  
High Level ◽  
Spilling Breakers

Abstract The forces on marine and offshore structures are often affected by spilling breakers. The spilling breaker is characterized by a roller of mixed air and water with a forward speed approximately equal to the wave celerity. This high speed in the top of the wave has the potential to induce high wave loads on upper parts of the structures. This study analyzed the effect of the air content on the forces. The analyses used the Morison equation to examine the effect of the percentage of air on the forces. An experimental set-up was developed to include the injection of air into an otherwise calm water body. The air-injection did introduce a high level a turbulence. It was possible to assess the amount of air content in the water for different amounts of air-injection. In the mixture of air and water the force on an oscillating square cylinder was measured for different levels of air-content, — also in the case without air. The measurements indicated that force coefficients for clear water could be use in the Morison equation as long as the density for water was replaced by the density for the mixture of air and water.

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