The Inlet Flow Blockage Accidents Analysis in the Rectangular flow channel of water cooled blanket

2021 ◽  
Vol 171 ◽  
pp. 112605
Author(s):  
Xiangyu Li ◽  
Changhong Peng ◽  
Yun Guo
Keyword(s):  
Flow Channel ◽  
Inlet Flow ◽  
Flow Blockage

ATR Flow Blockage Tests and CFD Simulations

2000 ◽  
Author(s):  
Chang H. Oh ◽  
Steve A. Atkinson
Keyword(s):  
Flow Direction ◽  
Velocity Profiles ◽  
Flow Channel ◽  
Department Of Energy ◽  
Base Case ◽  
Side Channel ◽  
Measured Velocity ◽  
Channel Blockage ◽  
Parallel Channels ◽  
Flow Blockage

Abstract Steady state flow channel blockage tests were conducted at the Idaho National Engineering and Environmental Laboratory (INEEL) as part of the safety basis upgrade program for the Advanced Test Reactor (ATR). The tests were sponsored by the U.S. Department of Energy (DOE). This study was aimed at carrying out flow blockage tests, establishing a base case to compare test results with numerical results using a computational fluid dynamics code, calculating temperature profiles for blockage cases, and determining whether or not the ATR core would be exposed to core melting due to blockage of the inlet of a fuel cooling channel. The test section consisted of three parallel channels and two side channels along the side plate. Three cases were selected to evaluate flow blockage events in the channels. A base case with all the channels open, Case 1 where the inlet of the middle channel is blocked, and Case 2 where both the middle channel and the side channel are blocked. Laser Doppler anemometer (LDA) was used to measure velocities in the channel. Velocities were measured at 2.54-mm intervals in the channel width, and every 1.27-mm around side windows in the flow direction for three parallel channels. LDA measured velocity profiles for the base case and Case 1 indicated good agreement with predicted velocity profiles from the CFD model. The channel velocity in the blocked channel is about 70% of the velocity in the unblocked, adjacent channel in between the top and second side channel vents. Additional flow redistribution occurs into the blocked channel at the second side channel vent. Temperature calculations for the base case were made to compare with benchmark temperatures calculated with the ATR SINDA model and CFD calculations underpredicted benchmark plate temperatures by less than 10% while it predicted bulk temperatures very well. The same heat flux and boundary conditions were incorporated for Case 1 and Case 2. The results for both cases indicated that core melt would not occur in the postulated ATR flow channel blockage events simulated for this study. Peak fuel plate temperature is about 20% greater than the peak temperature for the unblocked case just upstream of the second side channel vent.

CFD study on inlet flow blockage accidents in rectangular fuel assembly

2015 ◽  
Vol 292 ◽  
pp. 177-186 ◽  
Author(s):  
Wenyuan Fan ◽  
Changhong Peng ◽  
Yun Guo
Keyword(s):  
Fuel Assembly ◽  
Inlet Flow ◽  
Flow Blockage

scholarly journals Numerical Study on Pressure Pulsation in a Slanted Axial-Flow Pump Device under Partial Loads

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1404
Author(s):  
Fan Yang ◽  
Pengcheng Chang ◽  
Wenzhu Hu ◽  
Beibei Mao ◽  
Chao Liu ◽  
...  
Keyword(s):  
Pressure Fluctuation ◽  
Pressure Pulsation ◽  
Low Frequency ◽  
Axial Flow ◽  
Flow Channel ◽  
Monitoring Point ◽  
Inlet Flow ◽  
Main Frequency ◽  
Axial Flow Pump ◽  
Flow Pump

The 30° slanted axial-flow pump device is widely used in agricultural irrigation and urban drainage in plains areas of China. However, during the actual operation process, the 30° slanted axial-flow pump device is prone to vibration, noise, cracks in the blades, and other phenomena that affect the safe and stable operation of the pump device. In order to analyze the flow pressure pulsation characteristics of the 30° slanted axial-flow pump device under different flow conditions, the time–frequency domain analysis method was used to analyze the pressure pulsation of each flow structure of the 30° slanted axial-flow pump device. The results showed that the internal pulsation law of the elbow oblique inlet flow channel is similar. At the 1.2 Qbep condition, the amplitude fluctuation of the pressure pulsation was small, and the main frequency is 4 times the rotating frequency. The monitoring points at the outlet of the elbow oblique inlet flow channel were affected by the impeller rotation, and the pressure pulsation amplitude was larger than that inside the elbow oblique inlet flow channel. The pressure fluctuation of each monitoring point at the inlet surface of the impeller was affected by the number of blades. There were four peaks and four valleys, and the main frequency was 4 times the rotating frequency. The amplitude of pressure fluctuation increased gradually from the hub to the rim. The main frequency of pressure fluctuation at each monitoring point of the impeller outlet surface was 4 times of the rotating frequency, and the low frequency was rich. The amplitude of pressure fluctuation was significantly lower than that of the impeller inlet. With the increase of flow rate, the peak fluctuation of pressure coefficient decreased gradually, and the amplitude of pressure fluctuation tended to be stable. Under 0.8 Qbep and 1.0 Qbep conditions, the large fluctuation of the pressure fluctuation amplitude on the outlet surface of the guide vane was mainly affected by the low-frequency fluctuation. Under the 1.2 Qbep condition, the pressure fluctuation amplitude changed periodically.

The Influence of Tabs on Different Area Ratio Short Annular Diffusers

2014 ◽  
Author(s):  
D. J. Cerantola ◽  
A. M. Birk
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Layer Thickness ◽  
Boundary Layer Thickness ◽  
Pressure Coefficient ◽  
Area Ratio ◽  
Back Pressure ◽  
Swirl Number ◽  
Inlet Flow ◽  
Flow Blockage

Square tabs were placed on the base of an ellipsoidal centre body in annular diffusers with length to inlet height of 12. Tests were completed with an inlet Reynolds number of 1 × 105, swirl number of 0.71, and inlet flow blockage of 0.02–0.04. Four outer walls were manufactured with area ratios of 1.61, 1.91, 2.73, and 6.18. The tabs with a projected height equivalent to the boundary layer thickness were effective at reducing the outlet distortion but at a pressure penalty for the three smaller diffusers. The largest diffuser improved back pressure coefficient 4.6% with four tabs providing a blockage of 4.7% over its bare diffuser but was 42% lower than that obtained by the AR = 2.73 diffuser with no tabs.

Flow Visualization Pattern on Sharp Edge T-Junction through Dividing Flow Channel

2014 ◽  
Vol 493 ◽  
pp. 62-67 ◽  
Author(s):  
Y.B. Lukiyanto ◽  
I.N.G. Wardana ◽  
Widya Wijayanti ◽  
M. Agus Choiron
Keyword(s):  
Flow Visualization ◽  
Flow Pattern ◽  
Flow Model ◽  
Flow Channel ◽  
Sharp Edge ◽  
Inlet Flow ◽  
Head Losses ◽  
Model Scale ◽  
Outlet Flow ◽  
Static Conditions

In the previous study, sharp edge T-junction had been investigated to determine head losses and flow pattern. In this study, sharp edge T-junction was used as inlet flow model scale to determine flow visualization pattern. The apparatus test provide a dividing flow channel on static conditions which is the inlet pressure larger than 1 atm. Pressure difference is measured by using a U-pipe manometer. The manometer was inserted between inlet and outlet. Flow rate is measured by collecting fluid into a measuring cup. The coefficient of losses is determined as a result for predicting the losses energy. Flow Visualization Pattern is one of solution to perform the mechanism of sharp edge T-junction as inlet flow model scale. The result shows that flow pattern from simulation has the same trend with experimental results.

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