Effects of Cooling Fluid Flow Rate on the Critical Heat Flux and Flow Stability in the Plate Fuel Type 2 MW TRIGA Reactor

Abstract An analysis is made of the suction holding power of a device in which a fluid flows radially outward from a central hole between two parallel circular plates. The holding power and the fluid flow rate are determined as functions of the plate separation. The effect of changing the proportions of the device is investigated. Experiments were made to check the analysis.

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Estimation of Flow Rate Through Analysis of Pipe Vibration

Acta Mechanica et Automatica ◽

10.2478/ama-2018-0045 ◽

2018 ◽

Vol 12 (4) ◽

pp. 294-300 ◽

Cited By ~ 1

Author(s):

Santhosh K. Venkata ◽

Bhagya R. Navada

Keyword(s):

Neural Network ◽

Fluid Flow ◽

Flow Rate ◽

Back Propagation ◽

Vibration Signal ◽

Vibration Sensor ◽

Percentage Error ◽

Fluid Flow Rate ◽

Bee Colony ◽

Neural Network Algorithm

Abstract In this paper, implementation of soft sensing technique for measurement of fluid flow rate is reported. The objective of the paper is to design an estimator to physically measure the flow in pipe by analysing the vibration on the walls of the pipe. Commonly used head type flow meter causes obstruction to the flow and measurement would depend on the placement of these sensors. In the proposed technique vibration sensor is bonded on the pipe of liquid flow. It is observed that vibration in the pipe varies with the control action of stem. Single axis accelerometer is used to acquire vibration signal from pipe, signal is passed from the sensor to the system for processing. Basic techniques like filtering, amplification, and Fourier transform are used to process the signal. The obtained transform is trained using neural network algorithm to estimate the fluid flow rate. Artificial neural network is designed using back propagation with artificial bee colony algorithm. Designed estimator after being incorporated in practical setup is subjected to test and the result obtained shows successful estimation of flow rate with the root mean square percentage error of 0.667.

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A Study of Critical Heat Flux During Flow Boiling in Microchannel Heat Sinks

Journal of Heat Transfer ◽

10.1115/1.4004715 ◽

2011 ◽

Vol 134 (1) ◽

Cited By ~ 16

Author(s):

Tailian Chen ◽

Suresh V. Garimella

Keyword(s):

Heat Flux ◽

Critical Heat Flux ◽

Flow Rate ◽

Heat Input ◽

Heat Sink ◽

Flow Boiling ◽

Strong Dependence ◽

Heat Fluxes ◽

Abrupt Decrease ◽

Parallel Microchannels

The cooling capacity of two-phase transport in microchannels is limited by the occurrence of critical heat flux (CHF). Due to the nature of the phenomenon, it is challenging to obtain reliable CHF data without causing damage to the device under test. In this work, the critical heat fluxes for flow boiling of FC-77 in a silicon thermal test die containing 60 parallel microchannels were measured at five total flow rates through the microchannels in the range of 20–80 ml/min. CHF is caused by dryout at the wall near the exit of the microchannels, which in turn is attributed to the flow reversal upstream of the microchannels. The bubbles pushed back into the inlet plenum agglomerate; the resulting flow blockage is a likely cause for the occurrence of CHF which is marked by an abrupt increase in wall temperature near the exit and an abrupt decrease in pressure drop across the microchannels. A database of 49 data points obtained from five experiments in four independent studies with water, R-113, and FC-77 as coolants was compiled and analyzed. It is found that the CHF has a strong dependence on the coolant, the flow rate, and the area upon which the heat flux definition is based. However, at a given flow rate, the critical heat input (total heat transfer rate to the coolant when CHF occurs) depends only on the coolant and has minimal dependence on the details of the microchannel heat sink (channel size, number of channels, substrate material, and base area). The critical heat input for flow boiling in multiple parallel microchannels follows a well-defined trend with the product of mass flow rate and latent heat of vaporization. A power-law correlation is proposed which offers a simple, yet accurate method for predicting the CHF. The thermodynamic exit quality at CHF is also analyzed and discussed to provide insights into the CHF phenomenon in a heat sink containing multiple parallel microchannels.

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Mechanical Impact Effects of Fluid Hammer Effects on Drag Reduction of Coiled Tubing

Journal of Energy Resources Technology ◽

10.1115/1.4051302 ◽

2021 ◽

pp. 1-10

Author(s):

Yongsheng Liu ◽

Xing Qin ◽

Yuchen Sun ◽

Zijun Dou ◽

Jiansong Zhang ◽

...

Keyword(s):

Fluid Flow ◽

Drag Reduction ◽

Flow Rate ◽

Fluid Velocity ◽

Fluid Pressure ◽

Great Influence ◽

Radial Force ◽

Fluid Flow Rate ◽

Normal Contact ◽

Coiled Tubing

Abstract Aiming at the oscillation drag reduction tool that improves the extension limit of coiled tubing downhole operations, the fluid hammer equation of the oscillation drag reducer is established based on the fluid hammer effect. The fluid hammer equation is solved by the asymptotic method, and the distribution of fluid pressure and flow velocity in coiled tubing with oscillation drag reducers is obtained. At the same time, the axial force and radial force of the coiled tubing caused by the fluid hammer oscillator are calculated according to the momentum theorem. The radial force will change the normal contact force of the coiled tubing which has a great influence on frictional drag. The results show that the fluid flow rate and pressure decrease stepwise from the oscillator position to the wellhead position, and the fluid flow rate and pressure will change abruptly during each valve opening and closing time. When the fluid passes through the oscillator, the unit mass fluid will generate an instantaneous axial tension due to the change in the fluid velocity, thereby converting the static friction into dynamic friction, which is conducive to the extend limit of coiled tubing.

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Effect of Cutting Parameters on the Surface Residual Stress of Face-Milled Pearlitic Ductile Iron

International Journal of Materials Forming and Machining Processes ◽

10.4018/ijmfmp.2017010103 ◽

2017 ◽

Vol 4 (1) ◽

pp. 38-52

Author(s):

Olutosin Olufisayo Ilori ◽

Dare A. Adetan ◽

Lasisi E. Umoru

Keyword(s):

Residual Stress ◽

Fluid Flow ◽

Flow Rate ◽

Ductile Iron ◽

Cutting Parameters ◽

Cutting Fluid ◽

Depth Of Cut ◽

Fluid Flow Rate ◽

Surface Residual Stress ◽

Average Surface

The study determined the effect of cutting parameters on the surface residual stress of face-milled pearlitic ductile iron with a view to enhancing surface integrity of machined parts in the manufacturing industries. The pearlitic ductile iron used for this study was prepared and four cutting parameters were considered. The results obtained showed that the average surface residual stress of the machined surfaces was tensile and increased significantly with increase in depth of cut. Feed rate and cutting speed exhibited some effect, though not statistically significant, on average surface residual stress. The average residual stress was found to decrease significantly and drastically from 605.39 MPa to 101.72 MPa as cutting fluid flow rate increased from 0 ?/min to 4 ?/min. The study concluded that out of all four cutting parameters investigated, the cutting fluid flow rate has most considerable influence on the surface residual stress of the machined pearlitic ductile iron.

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Nonlinear Autoregressive Neural Networks to Predict Hydraulic Fracturing Fluid Leakage into Shallow Groundwater

Water ◽

10.3390/w12030841 ◽

2020 ◽

Vol 12 (3) ◽

pp. 841 ◽

Cited By ~ 2

Author(s):

Reza Taherdangkoo ◽

Alexandru Tatomir ◽

Mohammad Taherdangkoo ◽

Pengxiang Qiu ◽

Martin Sauter

Keyword(s):

Neural Networks ◽

Fluid Flow ◽

Hydraulic Fracturing ◽

Flow Rate ◽

Shallow Groundwater ◽

Fluid Flow Rate ◽

Shallow Aquifers ◽

Fracturing Fluid ◽

Upward Migration ◽

Nonlinear Autoregressive

Hydraulic fracturing of horizontal wells is an essential technology for the exploitation of unconventional resources, but led to environmental concerns. Fracturing fluid upward migration from deep gas reservoirs along abandoned wells may pose contamination threats to shallow groundwater. This study describes the novel application of a nonlinear autoregressive (NAR) neural network to estimate fracturing fluid flow rate to shallow aquifers in the presence of an abandoned well. The NAR network is trained using the Levenberg–Marquardt (LM) and Bayesian Regularization (BR) algorithms and the results were compared to identify the optimal network architecture. For NAR-LM model, the coefficient of determination (R2) between measured and predicted values is 0.923 and the mean squared error (MSE) is 4.2 × 10−4, and the values of R2 = 0.944 and MSE = 2.4 × 10−4 were obtained for the NAR-BR model. The results indicate the robustness and compatibility of NAR-LM and NAR-BR models in predicting fracturing fluid flow rate to shallow aquifers. This study shows that NAR neural networks can be useful and hold considerable potential for assessing the groundwater impacts of unconventional gas development.

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Tailoring surface acoustic wave atomisation for cryo-electron microscopy sample preparation

Lab on a Chip ◽

10.1039/c8lc01347k ◽

2019 ◽

Vol 19 (8) ◽

pp. 1378-1385 ◽

Cited By ~ 2

Author(s):

Dariush Ashtiani ◽

Alex de Marco ◽

Adrian Neild

Keyword(s):

Electron Microscopy ◽

Fluid Flow ◽

Sample Preparation ◽

Acoustic Wave ◽

Surface Acoustic Wave ◽

Flow Rate ◽

Fluid Flow Rate ◽

Cryo Electron Microscopy ◽

Electron Microscopy Grid

Surface acoustic wave (SAW) atomisation is investigated in the context of cryo electron microscopy grid preparation. Here, the primary requirements are a reproducible and narrow plume of droplets delivering a low fluid flow rate.

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