Pressure drop and flow characteristics in partially blocked wire wrapped rod bundles

Objective:The rheological properties of oil severely affect the determination of percolation theory, development program, production technology and oil-gathering and transferring process, especially for super heavy oil reservoirs. This paper illustrated the basic seepage morphology of super heavy oil in micro pores based on its rheological characteristics.Methods:The non-linear flow law and start-up pressure gradient of super heavy oil under irreducible water saturation at different temperatures were performed with different permeable sand packs. Meanwhile, the empirical formulas between start-up pressure gradient, the parameters describing the velocity-pressure drop curve and the ratio of gas permeability of a core to fluid viscosity were established.Results:The results demonstrate that temperature and core permeability have significant effect on the non-linear flow characteristics of super heavy oil. The relationship between start-up pressure gradient of oil, the parameters representing the velocity-pressure drop curve and the ratio of core permeability to fluid viscosity could be described as a power function.Conclusion:Above all, the quantitative description of the seepage law of super heavy oil reservoir was proposed in this paper, and finally the empirical diagram for determining the minimum and maximum start-up pressure of heavy oil with different viscosity in different permeable formations was obtained.

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Corrigendum to “The upgraded Cheng and Todreas correlation for pressure drop in hexagonal wire-wrapped rod bundles” [Nucl. Eng. Des. 335 (2018) 356–373]

Nuclear Engineering and Design ◽

10.1016/j.nucengdes.2018.10.009 ◽

2018 ◽

Vol 340 ◽

pp. 414

Author(s):

S.K. Chen ◽

Y.M. Chen ◽

N.E. Todreas

Keyword(s):

Pressure Drop ◽

Rod Bundles

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Experimental Investigation of Effect of Tip Coolant Ejection on Internal Flow Characteristics Within a Realistic Blade Coolant Channel

Volume 3A: Heat Transfer ◽

10.1115/gt2013-94136 ◽

2013 ◽

Author(s):

Jian Pu ◽

Zhaoqing Ke ◽

Jianhua Wang ◽

Lei Wang ◽

Hongde You

Keyword(s):

Experimental Investigation ◽

Reynolds Number ◽

Pressure Drop ◽

Turbine Blade ◽

Flow Rate ◽

Flow Characteristics ◽

Reynolds Numbers ◽

Flow Ratio ◽

Lp Turbine ◽

Mass Flow Ratio

This paper presents an experimental investigation on the characteristics of the fluid flow within an entire coolant channel of a low pressure (LP) turbine blade. The serpentine channel, which keeps realistic blade geometry, consists of three passes connected by a 180° sharp bend and a semi-round bend, 2 tip exits and 25 trailing edge exits. The mean velocity fields within several typical cross sections were captured using a particle image velocimetry (PIV) system. Pressure and flow rate at each exit were determined through the measurements of local static pressure and volume flow rate. To optimize the design of LP turbine blade coolant channels, the effect of tip ejection ratio (ER) from 180° sharp bend on the flow characteristics in the coolant channel were experimentally investigated at a series of inlet Reynolds numbers from 25,000 to 50,000. A complex flow pattern, which is different from the previous investigations conducted by a simplified square or rectangular two-pass U-channel, is exhibited from the PIV results. This experimental investigation indicated that: a) in the main flow direction, the regions of separation bubble and flow impingement increase in size with a decrease of the ER; b) the shape, intensity and position of the secondary vortices are changed by the ER; c) the mass flow ratio of each exit to inlet is not sensitive to the inlet Reynolds number; d) the increase of the ER reduces the mass flow ratio through each trailing edge exit to the extent of about 23–28% of the ER = 0 reference under the condition that the tip exit located at 180° bend is full open; e) the pressure drop through the entire coolant channel decreases with an increase in the ER and inlet Reynolds number, and a reduction about 35–40% of the non-dimensional pressure drop is observed at different inlet Reynolds numbers, under the condition that the tip exit located at 180° bend is full open.

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Numerical Simulation on Heat Transfer and Fluid Flow Characteristics of Arrays With Nonuniform Plate Length Positioned Obliquely to the Flow Direction

Journal of Heat Transfer ◽

10.1115/1.2825920 ◽

1998 ◽

Vol 120 (4) ◽

pp. 991-998 ◽

Cited By ~ 9

Author(s):

L. B. Wang ◽

G. D. Jiang ◽

W. Q. Tao ◽

H. Ozoe

Keyword(s):

Heat Transfer ◽

Pressure Drop ◽

Flow Direction ◽

Flow Characteristics ◽

Numerical Results ◽

The Body ◽

Number Range ◽

Plate Length ◽

Nonuniform Plate ◽

Short Plate

The periodically fully developed laminar heat transfer and pressure drop of arrays with nonuniform plate length aligned at an angle (25 deg) to air direction have been investigated by numerical analysis in the Reynolds number range of 50–1700. The body-fitted coordinate system generated by the multisurface method was adopted to retain the corresponding periodic relation of the lines in physical and computational domains. The computations were carried out just in one cycle. Numerical results show that both the heat transfer and pressure drop increase with the increase in the length ratio of the long plate to the short plate, and decrease with the decrease in the ratio of transverse pitch to the longitudinal pitch. The numerical results exhibit good agreement with available experimental data.

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Effect of Tube Diameter on Flow Phenomena of Gas-Liquid Two-Phase Flow in Microchannels

ASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels ◽

10.1115/icnmm2015-48143 ◽

2015 ◽

Cited By ~ 1

Author(s):

Hideo Ide ◽

Eiji Kinoshita ◽

Ryo Kuroshima ◽

Takeshi Ohtaka ◽

Yuichi Shibata ◽

...

Keyword(s):

Pressure Drop ◽

High Speed ◽

Water Solution ◽

Flow Direction ◽

Flow Characteristics ◽

Tube Diameter ◽

Two Phase ◽

Frictional Pressure Drop ◽

Flow Phenomena ◽

The Waves

Gas-liquid two-phase flows in minichannels and microchannels display a unique flow pattern called ring film flow, in which stable waves of relatively large amplitudes appear at seemingly regular intervals and propagate in the flow direction. In the present work, the velocity characteristics of gas slugs, ring films, and their features such as the gas slug length, flow phenomena and frictional pressure drop for nitrogen-distilled water and nitrogen-30 wt% ethanol water solution have been investigated experimentally. Four kinds of circular microchannels with diameters of 100 μm, 150 μm, 250 μm and 518 μm were used. The effects of tube diameter and physical properties, especially the surface tension and liquid viscosity, on the flow patterns, gas slug length and the two-phase frictional pressure drop have been investigated by using a high speed camera at 6,000 frames per second. The flow characteristics of gas slugs, liquid slugs and the waves of ring film are presented in this paper.

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3D Computational Analysis of Thermal and Hydraulic Performance of Louvered Fin Heat Exchanger With Variable Louver Angle and Louver Pitch

Volume 6B: Energy ◽

10.1115/imece2016-66534 ◽

2016 ◽

Cited By ~ 2

Author(s):

Abdulkerim Okbaz ◽

Ali Pınarbaşı ◽

Ali Bahadır Olcay

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Pressure Drop ◽

Flow Characteristics ◽

Hydraulic Performance ◽

Double Row ◽

Louvered Fin ◽

Goodness Factor ◽

Fluid Flow Characteristics ◽

Louvered Fins

In the present study, 3-D numerical simulations on heat and fluid flow characteristics of double-row multi-louvered fins heat exchanger are carried out. The heat transfer improvement and the corresponding pressure drop amounts were investigated depending on louver angles in the range of 20° ≤θ≤ 30°, louver pitches of Lp = 2,7mm, 3,5mm and 3,8mm and frontal velocities of Uin between 1.22 m/s and 3 m/s. The results are reported in terms of Colburn j-factor, Fanning friction factor f and area goodness factor j/f based on louver angle, louver pitch and Reynolds number. To understand local behavior of flow around louvered fins and heat exchanger tubes, flow visualization results of velocity vectors and stream-lines with temperature counters are presented. It is investigated that increasing louver angle enhances convective heat transfer while hydraulic performance decreases due to increased pressure drop. The flow noticeably behaves louver directed for all louver angles The flow can easily travel between different fins. This case study has been done to design and manufacture an industrial louver fin heat exchanger.

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CFD Study on the Flow Characteristics in Filleted Microchannels

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.103.268 ◽

2011 ◽

Vol 103 ◽

pp. 268-273

Author(s):

Hong Jie Yan ◽

Ping Zhou ◽

Ze Lin Xu ◽

Zhuo Chen ◽

Jing Wen Mo

Keyword(s):

Pressure Drop ◽

Aspect Ratio ◽

Flow Model ◽

Constant Width ◽

Flow Characteristics ◽

Flow Pressure ◽

Cfd Method ◽

Poiseuille Number ◽

The Relationship ◽

Laminar Flow Model

The flow characteristics of water in filleted microchannels were simulated based on CFD method. The flow pressure drop at different aspect ratioandRenumber were rearranged on the simulating results with laminar flow model. The results indicated that the pressure drop enlarges with the increase of in the case of the constant width of the microchannel. Within the range ofRenumber of interest, Poiseuille number of the flow is constant for differentRe, but decreases with increasing aspect ratio. An equation was fitted to describe the relationship betweenPonumber and aspect ratio, i.e. .

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THREE DIMENSIONAL SIMULATION OF OIL FLOW CHARACTERISTICS IN LUBRICATION SYSTEM OF ROTARY TILLAGE ENGINE

INMATEH Agricultural Engineering ◽

10.35633/inmateh-65-17 ◽

2021 ◽

pp. 163-172

Author(s):

Junxiang Gao ◽

Xiaoliang Gao ◽

Wei Zou

Keyword(s):

Pressure Drop ◽

Three Dimensional ◽

Flow Characteristics ◽

Lubricating Oil ◽

Flow Index ◽

Lubrication System ◽

Pump Rotor ◽

Oil Pump ◽

Oil Flow ◽

Dimensional Simulation

Taking the lubrication system of rotary tillage engine as the research object, this paper makes a three-dimensional simulation study on the oil flow characteristics in the lubricating oil passage. The oil supply of the oil pump shall be greater than the circulating oil required by the lubrication system to ensure the lubrication of the rotary cultivator. Lubrication system is an important part to ensure the reliability and durability of rotary cultivator. The key component to achieve its performance is the oil pump. The geometric model of lubricating oil flow field in rotary tiller lubrication system is established by using FLUENT software. The results show that the pressure drop in the lubricating oil passage of the main bearing is the largest under the same working conditions. In the oil passage of the cylinder head, the pressure drop of the front main oil passage is the largest and the oil discharge is the largest. Add 1.6mm oil pump rotor on the basis of the thickness of the original oil pump rotor, the oil flow at the connecting rod nozzle reaches the flow index of the original rotary cultivator, and there is no cylinder pulling phenomenon of the rotary cultivator.

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