Experimental Study on the Flow Characteristics of Rod Bundle Under Rolling Motion

2021 ◽  
Author(s):  
Xin Li ◽  
Peiyao Qi ◽  
Sichao Tan ◽  
Chao Qi ◽  
Shouxu Qiao
Keyword(s):  
Flow Field ◽  
Driving Force ◽  
Flow Characteristics ◽  
Inertial Force ◽  
Pulsating Flow ◽  
Reactor System ◽  
Rolling Motion ◽  
Field Variation ◽  
Transverse Mixing ◽  
Rod Bundle

Abstract The floating reactor system will be rolling, heaving and other movements affected by waves, wind, etc. These motions will introduce additional inertial force field into the rod bundle, thus affecting the flow characteristics in the rod bundle channel. In order to study the influence of rolling motion on the flow characteristics of rod bundle, a visualization research of the flow field of rod bundle channel with a pitch-to-diameter ratio of 1.326 was carried out under rolling motion. The results show that under a small driving force, the rolling motion has a significant effect on the flow field in the rod bundle, affecting the velocity distribution in different sub-channels, and there is transverse mixing between adjacent sub-channels. With the increase of driving force, the influence of rolling motion is gradually weakened. The flow field distribution under rolling motion is significantly different from that under pulsating flow. The experimental results show that the influence of rolling motion on the middle sub-channel of the rod bundle channel is small, and the influence on the edge sub-channel is large. The velocity field of the subchannels on both sides of the edge fluctuates periodically, and the wave phase is inverse. This study shows that the flow field variation caused by rolling motion is different from that caused by pulsating flow, and the flow field of fuel assembly in floating reactor system under ocean condition is further studied.

Detailed Study of Pulsating Flow Performance in a Mixed Flow Turbocharger Turbine

2005 ◽  
Author(s):  
Aaron Costall ◽  
Ricardo F. Martinez-Botas ◽  
Dean Palfreyman
Keyword(s):  
Flow Field ◽  
Combustion Engine ◽  
Flow Direction ◽  
Flow Characteristics ◽  
Pulsating Flow ◽  
Turbine Stage ◽  
Complex Flow ◽  
Pulse Period ◽  
Pulse Profile ◽  
Direction Control

Automotive turbocharger turbines experience a highly unsteady and pulsating flow field due to the abrupt operation of the exhaust valves in a reciprocating internal combustion engine. Previous work has demonstrated and validated against experiment a computational model of a turbine stage under such conditions. The same model is used in the present paper to examine in greater detail the complex flow characteristics observed. The pulsating inlet condition results in a highly disturbed flow field in the turbine stage, the main features of which have already been identified. The effect of the passing of the blades at the volute tongue is observed, and the fluctuating velocity field in the blade passages is seen to lead to poor flow direction control at the turbine inlet and exit. The turbine geometry, calculated for steady flow, is forced to operate away from design conditions for most of the pulse period. Through a detailed analysis of the intricate flow field features at varying instants during the pulse period, this paper highlights areas of the blade geometry and periods in the pulse profile that should be investigated further, such that the integrated performance across the entire pulse cycle can be improved.

scholarly journals MODELOVÁ CIRKULACE FLUID V EXPERIMENTÁLNÍ NÁDOBĚ MOCK-UP-CZ

2016 ◽  
Vol 22 (1-2) ◽  
Author(s):  
Martin Šrámek ◽  
Tomáš Kuchovský
Keyword(s):  
Fluid Flow ◽  
Thermal Properties ◽  
Flow Field ◽  
Numerical Modelling ◽  
Driving Force ◽  
Spent Nuclear Fuel ◽  
Flow Characteristics ◽  
Computer Code ◽  
Temperature Fields ◽  
Fluid Flow Characteristics

Experiment simulating the storage of spent nuclear fuel in the canister filled by bentonite mixture took place in the Center of experimental Geotechnics (CEG) on the Faculty of Civil engineering of the Czech Technical University in Prague during the years 2002–2006. After the realisation of the experiment it was shown, that both non-homogeneous geochemical and temperature fields were established. The main aim of the work was focused on the evaluation of the fluid flow characteristics inside the container, especially on the direction and flow velocities influenced by the increased temperature. Numerical modelling using the SHEMAT computer code was used to simulate the fluid flow.Mathematical modelling confirmed the probable formation of the convection cells along the heater with variable velocities depending on the hydraulic and thermal properties of the bentonite mixture and on the physical properties of the saturating fuid. The generated flow field could be the driving force for the geochemical non-homogeneities.

Thermo-flow characteristics and air flow field leading of the air-cooled condenser cell in a power plant

2011 ◽  
Vol 54 (9) ◽  
pp. 2475-2482 ◽  
Author(s):  
WanXi Zhang ◽  
LiJun Yang ◽  
XiaoZe Du ◽  
YongPing Yang
Keyword(s):  
Power Plant ◽  
Flow Field ◽  
Air Flow ◽  
Flow Characteristics

scholarly journals Study on the 3D Hydrodynamic Characteristics and Velocity Uniformity of a Gravity Flow Circular Flume

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 927
Author(s):  
Yi Zhang ◽  
Longxi Han ◽  
Lina Chen ◽  
Chenfang Wang ◽  
Bo Chen ◽  
...  
Keyword(s):  
Flow Field ◽  
Environmental Science ◽  
Structural Characteristics ◽  
Longitudinal Velocity ◽  
Flow Characteristics ◽  
Science Research ◽  
Hydrodynamic Characteristics ◽  
Straight Channel ◽  
Uniformity Coefficient ◽  
Annular Flume

Flumes have been widely used in water conservancy science and environmental science research. It is of great significance to obtain the hydrodynamic characteristics and flow field uniformity in the flume. In this study, a new type of annular flume was taken as an example. The 3D flow field was simulated by using a commercial computational fluid dynamics (CFD) code, and was also measured by acoustic doppler velocimeter (ADV) to verify the simulation results. The average relative error range was between 8.37% and 9.95%, the simulated results basically reflected the actual situation of the flow field. On this basis, the structural characteristics of flow field were analyzed. A new calculation method of flow velocity uniformity was presented according to the flow characteristics of natural open channels. The velocity uniformity in the straight channel was calculated and analyzed based on this method, and the influence of speed on the velocity uniformity was further discussed. The length of uniform section was negatively correlated with the rotational speed (average velocity), which was between 39 cm and 101 cm in the straight, and the uniformity coefficient was less than 10%. Finally, the water flow characteristics in the straight channel without wheel were compared with the natural open channel flow. The longitudinal velocity was well fitted with the Prandtl logarithmic distribution formula (R2 > 0.977), and the application feasibility of the flume was analyzed. This study can provide technical support for the development and application of annular flume.

Effects of Valve Disc on Flow Characteristics Inside a Swing Check Valve During Opening and Closing Processes

2021 ◽  
Author(s):  
Yi-xiang Xu ◽  
Qiang Ru ◽  
Huai-yu Yao ◽  
Zhi-jiang Jin ◽  
Jin-yuan Qian
Keyword(s):  
Flow Field ◽  
Working Conditions ◽  
Power Plants ◽  
Flow Characteristics ◽  
Check Valve ◽  
Opening Angle ◽  
Piping System ◽  
Total Moment ◽  
Valve Disc ◽  
Opening And Closing

Abstract The check valve is one of the most important devices for safety protection of the piping system in thermal and nuclear power plants. As the key component of the check valve, the valve disc accounts for a major effect on the flow characteristics especially during the opening and closing processes. In this paper, a typical swing check valve is taken as the research object. In order to make a comparative study, three working conditions of 30% THA (Turbine Heat Acceptance), 50% THA and 100% THA are selected. Focusing on the effects of valve disc, how does the valve disc motion interact with the flow field around the valve disc is analyzed with the help of the dynamic mesh technology. The results show that under the combined action of fluid force and gravity, the check valve can be opened and closed quickly. During the opening process, the maximum total moment of the disc appears between 45° ∼ 50° opening angle, and during the closing process the maximum total moment occurs when the disc fully closed. The flow field near the valve disc has similar variation rules with the rotation of the valve disc in the three working conditions, and the pressure near the valve disc reaches the maximum value at the moment of opening and closing. This study can provide some suggestions for the further optimal design of similar swing check valve.

scholarly journals Flow Characteristics in a 3×3 Rod Bundle under Flooding Conditions

2020 ◽  
Author(s):  
Michio MURASE ◽  
Naoki SANO ◽  
Toshiya TAKAKI ◽  
Raito GODA ◽  
Kosuke HAYASHI ◽  
...  
Keyword(s):  
Flow Characteristics ◽  
Rod Bundle

scholarly journals Flow characteristics for structure of stenosis tubes with pulsating flow

2006 ◽  
Vol 26 (Supplement1) ◽  
pp. 77-80
Author(s):  
Tetsuo YOSHIDA ◽  
Hiroo OKANAGA ◽  
Kasumi AOKI
Keyword(s):  
Flow Characteristics ◽  
Pulsating Flow

scholarly journals Numerical Simulation and Experimental Study on Flow Field in a Swirl Nozzle

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yicheng Sun ◽  
Yufan Fu ◽  
Baohui Chen ◽  
Jiaxing Lu ◽  
Wanquan Deng
Keyword(s):  
Flow Field ◽  
Velocity Distribution ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Low Pressure ◽  
External Flow ◽  
Droplet Velocity ◽  
Inlet Pressure ◽  
Outlet Section ◽  
Local Pressure

In order to study the internal flow characteristics and external droplet velocity distribution characteristics of the swirl nozzle, the following methods were used: numerical simulations were used to study the internal flow characteristics of a swirl nozzle and phase Doppler particle velocimetry was used to determine the corresponding external droplet velocity distribution under medium and low pressure conditions. The distributions of pressure and water velocity inside the nozzle were obtained. Meanwhile, the velocities of droplets outside the nozzle in different sections were discussed. The results show that the flow rate in the swirl nozzle increases with the increase in inlet pressure, and the local pressure in the region decreases because of the excessive velocity at the internal outlet section of the swirl nozzle, resulting in cavitation. The experimental results show that under an external flow field, the minimum droplet velocity occurs in the axial direction; starting from the axis, the velocity first increases and then decreases along the radial direction. Swirling motion inside the nozzle and velocity variations in the external flow field occur under medium and low pressure conditions. The relationship between the inlet pressure and the distributions of water droplets’ velocities was established, which provides a reference for the research and development of the swirl nozzle.

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