Evaluation of Jet Impact Region and Fluid Force Generated From Ruptured Pipes: Part 4 — Numerical Evaluation of Affected Region by Flashing Jet Flow

2018 ◽  
Author(s):  
Ryo Morita ◽  
Shun Watanabe ◽  
Shiro Takahashi ◽  
Noriyuki Takamura
Keyword(s):  
Nuclear Power ◽  
Numerical Evaluation ◽  
Power Plants ◽  
Jet Impingement ◽  
Jet Flow ◽  
Dynamics Analysis ◽  
Flow Conditions ◽  
Jet Impact ◽  
Computational Fluid Dynamics Analysis ◽  
Impact Region

Nuclear power plants are designed to prevent the damage of safety installations and human safety due to the jet impingement when a pipe is ruptured. We have investigated evaluation methods for the design basis of protection of plants against effects of postulated pipe rupture using computational fluid dynamics analysis (CFD). The flashing steam jet was evaluated in this study. Shapes of flashing jet were obtained by CFD calculations, and we have found that the affected region was wider than usual steam jet flow and strongly depends on the nozzle exit flow conditions. This is thought as the different tendency from established standards.

Evaluation of Jet Impact Region and Fluid Force Generated From Ruptured Pipes: 1 — Numerical and Experimental Evaluation of Affected Region by Steam Jet

2016 ◽  
Author(s):  
Ryo Morita ◽  
Yuta Uchiyama ◽  
Shun Watanabe ◽  
Shiro Takahashi ◽  
Qiang Xu ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Particle Image ◽  
Jet Impingement ◽  
Dynamics Analysis ◽  
Free Jet ◽  
Jet Impact ◽  
Image Velocimetry ◽  
Computational Fluid Dynamics Analysis ◽  
Impact Region

Nuclear power plants are designed to prevent the damage of safety installations and human safety due to the jet impingement when a pipe is ruptured. We have investigated evaluation methods for the design basis of protection of plants against effects of postulated pipe rupture using computational fluid dynamics analysis (CFD). The steam jet tests using particle image velocimetry were conducted in order to verify the CFD methods. Spread of steam jet could be visualized. Shapes of steam jet obtained by CFD were almost the same as those by tests. The spread angle of free jet were investigated using CFD, and we have found that the spread angle strongly depends on the inlet pressure. This is thought as the different tendency from Established Standards.

Evaluation of Jet Impact Region and Fluid Force Generated From Ruptured Pipes: 3 — Evaluation of Established Standards

2016 ◽  
Author(s):  
Qiang Xu ◽  
Shiro Takahashi ◽  
Noriyuki Takamura ◽  
Ryo Morita ◽  
Yuta Uchiyama ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Evaluation Method ◽  
Jet Impingement ◽  
National Standards ◽  
Fluid Force ◽  
Fluid Forces ◽  
Jet Impact ◽  
Image Velocimetry ◽  
Impact Region

Nuclear power plants are designed to avoid damage to their safety installations because of jet impingement when a pipe is ruptured. We have investigated the evaluation method for the design basis of protection of plants against effects of a postulated pipe rupture using the established standard of the American National Standards Institute (ANSI). The steam jet tests using particle image velocimetry and computational fluid dynamics (CFD) analysis were conducted for this verification. Spread angle of steam jet could be visualized. The jet spread angles were lower than 10 deg which was described in the ANSI standard. The ANSI standard was conservative for evaluations of the jet impact region compared to actual test and CFD results. However, it is desirable to use the conservative angle for evaluation of the jet fluid force. We could adequately evaluate the conservative jet fluid forces by the ANSI standard considering the spread suppression region and jet spread angle of 6 deg.

Evaluation of Jet Impact Region and Fluid Force Generated From Ruptured Pipes: 2 — Evaluation of Fluid Force Using Computational Fluid Dynamics Analysis

2016 ◽  
Author(s):  
Shiro Takahashi ◽  
Qiang Xu ◽  
Noriyuki Takamura ◽  
Ryo Morita ◽  
Yuta Uchiyama ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Nuclear Power ◽  
Power Plants ◽  
Jet Impingement ◽  
Cfd Analysis ◽  
Fluid Force ◽  
Free Jet ◽  
Jet Impact ◽  
Computational Fluid Dynamics Analysis

Nuclear power plants are designed to avoid damage to their safety installations because of jet impingement when a pipe is ruptured. We have investigated evaluation methods for the design basis of protection of plants against effects of postulated pipe rupture using computational fluid dynamics (CFD) analysis. The steam jet tests obtained using particle image velocimetry (PIV) were conducted in order to verify the CFD analysis. Spread of steam jets could be visualized and the shapes of the steam jets obtained by analysis were almost the same as those by tests. The spread angle of free jet was investigated using CFD analysis. We also measured jet fluid force when a cylindrical structure was installed downstream from the jet nozzle. Steam jet fluid force obtained by analysis was almost the same as that by tests. We judged the CFD analysis to be applicable to evaluation of jet fluid force generated from ruptured pipes.

S0510301 Evaluation of Jet Impact Region Generated from Ruptured Pipes : (1) Numerical Evaluation of Asymptotic Region and Comparison with Established Standards

2015 ◽  
Vol 2015 (0) ◽  
pp. _S0510301--_S0510301-
Author(s):  
Ryo MORITA ◽  
Yuta UCHIYAMA ◽  
Shun WANATABE ◽  
Shiro TAKAHASHI ◽  
Noriyuki TAKAMURA ◽  
...  
Keyword(s):  
Numerical Evaluation ◽  
Asymptotic Region ◽  
Jet Impact ◽  
Impact Region

Development of Enertech’s Advanced Normally Open NozzleCheck Valves for Generation III+ Nuclear Power Plants

2014 ◽  
Author(s):  
Haykaz Mkrtchyan
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Reverse Flow ◽  
Flow Direction ◽  
Fluid Dynamic ◽  
High Capacity ◽  
Check Valve ◽  
Operating Conditions ◽  
Flow Conditions ◽  
Valve Design

Enertech introduced the first Normally Open NozzleCheck valves to the nuclear power industry nearly 20 years ago. This passive valve design was developed to address reoccurring maintenance and reliability issues often experienced by various check valve types due to low or turbulent flow conditions. Specifically, premature wear on the hinge pins, bushings and severe seat impact damage had been discovered in several applications while the systems were in steady state operating conditions. Over the last two decades, Enertech has continued to improve upon the design of the valve, with the culmination coming most recently in support of Generation III+ passive reactor requirements. This entirely new valve is designed with minimal stroke, ensuring quick closure under low reverse flow conditions which no other check valve design could support. Additionally, features such as first in kind test ports, visual inspection points, and the ability to manually stroke the valve in line have resolved many of the short comings of previous inline welded flow check valves. Most importantly, advanced test based methodologies and models developed by Enertech, allow for accurate prediction of NozzleCheck valve performance. This paper presents the development of Enertech’s advanced Normally Open NozzleCheck Valve for Generation III and III+ nuclear reactor designs. The Valve performance was initially determined by using verified and validated computational fluid dynamic (CFD) methods. The results obtained from the CFD model were then compared to the data gathered from a prototype valve that was built and tested to confirm the performance predictions. Enertech has fully tested and qualified the Normally Open NozzleCheck valve which is specifically designed for applications that require a high capacity in the forward flow direction and a quick closure during low reverse flow condition with short stroke to minimize the hydraulic impact on the system.

Curtiss-Wright Advanced NozzleCheck Valves for Generation III+ Nuclear Power Plants

2017 ◽  
Author(s):  
Haykaz Mkrtchyan ◽  
Ararat Torosyan ◽  
Tsolag Apelian
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Reverse Flow ◽  
Flow Direction ◽  
Fluid Dynamic ◽  
Check Valve ◽  
Operating Conditions ◽  
Low Flow ◽  
Flow Conditions ◽  
Valve Design

Curtiss Wright introduced the first Normally Open NozzleCheck valves to the nuclear power industry nearly 20 years ago. This passive valve design was developed to address reoccurring maintenance and reliability issues often experienced by various check valve types due to low flow conditions. Specifically, premature wear on the hinge pins, bushings and severe seat impact damage had been discovered in several applications while the systems were in steady state operating conditions. Over the last two decades, Curtiss Wright has continued to improve upon the design of the valve, with the latest generation coming most recently in support of the Westinghouse AP1000 design and similar Generation III+ passive reactor requirements. This entirely new valve is designed with minimal stroke, ensuring quick closure under specified reverse flow conditions which no other check valve design could support. Additionally, features such as first in kind test ports, visual inspection points, and the ability to stroke the valve manually or with system fluid in line have resolved many of the shortcomings of previous inline welded flow check valves. Most importantly, advanced test based methodologies and models developed by Curtiss Wright, allow for accurate prediction of NozzleCheck valve performance. This paper presents the development of Curtiss Wright’s advanced Normally Open NozzleCheck Valve for Generation III and III+ nuclear reactor designs. The Valve performance was initially determined by using verified and validated computational fluid dynamic (CFD) methods. The results obtained from the CFD model were then compared to the data gathered from a prototype valve that was built and tested to confirm the performance predictions. Curtiss Wright has fully tested and qualified the Normally Open NozzleCheck valve, which is specifically designed for applications that require a high capacity in the forward flow direction and a closure at low flow rates with short stroke to minimize the hydraulic impact on the system. Paper published with permission.

Nozzle Geometry Effect on Stratified Layer Erosion by Vertical Turbulent Jet

2017 ◽  
Vol 3 (3) ◽  
Author(s):  
L. Ishay ◽  
U. Bieder ◽  
G. Ziskind ◽  
A. Rashkovan
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Jet Impingement ◽  
Turbulent Jets ◽  
Turbulent Jet ◽  
Severe Accident ◽  
Nozzle Geometry ◽  
Correct Prediction ◽  
Jet Mixing ◽  
Jet Behavior

Knowledge of the nuclear power plants (NPPs) containment atmosphere composition in the course of a severe accident is crucial for the effective design and positioning of the hydrogen explosion countermeasures. This composition strongly depends on containment flows which may include turbulent jet mixing in the presence of buoyancy, jet impingement onto the stratified layer, stable stratification layer erosion, steam condensation on the walls of the containment, condensation by emergency spray systems and other processes. Thus, in modeling of containment flows, it is essential to correctly predict these effects. In particular, a proper prediction of the turbulent jet behavior before it reaches the stably stratified layer is critical for the correct prediction of its mixing and impingement. Accordingly, validation study is presented for free neutral and buoyancy-affected turbulent jets, based on well-known experimental results from the literature. This study allows for the choice of a proper turbulence model to be applied for containment flow simulations. Furthermore, the jet behavior strongly depends on the issuing geometry. A comparative study of erosion process for the conditions similar to the ones of international benchmark exercise (IBE-3) is presented for different jet nozzle shapes.

Computational fluid dynamics analysis of the wake behind the MEXICO rotor in axial flow conditions

Wind Energy ◽  
2014 ◽  
Vol 18 (6) ◽  
pp. 1023-1045 ◽  
Author(s):  
M. Carrión ◽  
R. Steijl ◽  
M. Woodgate ◽  
G. Barakos ◽  
X. Munduate ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Axial Flow ◽  
Dynamics Analysis ◽  
Flow Conditions ◽  
Computational Fluid Dynamics Analysis
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