Analysis of pressure losses and flow distribution in wire-wrapped hexagonal rod bundles for licensing. Part II: Evaluation of public experimental data

2021 ◽  
pp. 111606
Author(s):  
J. Pacio ◽  
S.K. Chen ◽  
Y.M. Chen ◽  
N.E. Todreas
Keyword(s):  
Experimental Data ◽  
Flow Distribution ◽  
Rod Bundles ◽  
Pressure Losses

An experimental investigation of oblique entry pressure losses in automotive catalytic converters

2009 ◽  
Vol 223 (11) ◽  
pp. 2561-2569 ◽  
Author(s):  
S S Quadri ◽  
S F Benjamin ◽  
C A Roberts
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Experimental Investigation ◽  
Reynolds Number ◽  
Flow Distribution ◽  
Angle Of Incidence ◽  
Pressure Losses ◽  
Entry Pressure ◽  
Automotive Catalytic Converters

This study investigates oblique entry pressure loss in automotive catalyst monoliths. Experiments have been performed on a specially designed flow rig using different lengths of monolith (17—100 mm) over a range of Reynolds number and angles of incidence (0–75°). Losses were found to be a function of Reynolds number and angle of incidence and a general correlation has been derived. Computational fluid dynamics predictions of the flow distribution across axisymmetric catalyst assemblies have been performed. Incorporating the oblique entry loss provided much better agreement with experimental data with the assumption that such losses were constant above an angle of incidence of 81°.

Buoyancy Effect on Heat Transfer in 5×5 Rod Bundles

2017 ◽  
Author(s):  
Da Liu ◽  
Fujun Gan ◽  
Chaozhu Zhang ◽  
Hanyang Gu
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mixed Convection ◽  
Buoyancy Force ◽  
Reynold Number ◽  
Low Flow ◽  
Buoyancy Effect ◽  
Rod Bundles ◽  
Convection Regime ◽  
Dc Power

Experiments of heat transfer at low flow rate are performed in a 5×5 square arrayed rod bundles. The diameter of the rod is 10mm with a pitch of 13.3mm, length of the test section is about 3 meters. Inlet Reynold number ranges from 2000 to 30000, Bo * ranges from 4×10−6 to 5×10−3. The rods are heated using a DC power, the heat flux ranges from 30 to 300 kW/m2. The experiment is aimed to investigate the buoyancy effect of mixed convection in rod bundles. The experimental data shows that similar with mixed convection in circular channels, buoyancy force has great effect on heat transfer at mixed convection regime in rod bundles. But the buoyancy effect appears at higher Bo* conditions. The spacer effect have also been investigated at both turbulent forced convection regime and mixed convection regime. The reconstruction of heat transfer downstream of spacers is different at different flow regimes, a reasonable explanation was provided.

A Study on the Blade Shape Influence on Flow Distribution and Performance in Centrifugal Compressor Rotors

1990 ◽  
Author(s):  
Raffaele Tuccillo ◽  
Adolfo Senatore
Keyword(s):  
Flow Pattern ◽  
Boundary Layers ◽  
Centrifugal Compressor ◽  
Flow Distribution ◽  
Aircraft Engine ◽  
Pressure Losses ◽  
Compressor Rotor ◽  
Blade Shape ◽  
Shape Influence ◽  
And Performance

The authors present an analysis of the flow through a centrifugal compressor rotor. A quasi-3D flow model evaluates the interaction of the meridional and blade-to-blade solution, so as to determine the flow pattern inside an inviscid region. A further interaction is then considered between the non-viscous flow and the boundary layers which grow along the end-walls and the blade surfaces. This makes it possible both to determine a more realistic flow condition, because of the blockage effects exerted by the boundary layers, and to estimate the total pressure losses related to the momentum thickness. Examples are presented for a compressor of an aircraft engine. The influence of blade shape on the above described phenomena is analyzed, starting from the actual rotor geometry and making a parametric study of the alterations in flow pattern produced by changes in meridional blade shape, inlet and outlet flow areas, and splitter blades. The analysis will provide a basis for future activities involving the use of optimizing techniques for the final choice of the blade characteristics.

Frictional Pressure Losses for Annular Flow of Drilling Mud and Mud-Gas Mixtures

1985 ◽  
Vol 107 (1) ◽  
pp. 142-151 ◽  
Author(s):  
J. P. Langlinais ◽  
A. T. Bourgoyne ◽  
W. R. Holden
Keyword(s):  
Experimental Data ◽  
Single Phase ◽  
Two Phase Flow ◽  
Hydraulic Diameter ◽  
Phase Flow ◽  
Drilling Mud ◽  
Two Phase ◽  
Bingham Plastic ◽  
Pressure Losses ◽  
Annular Geometry

The calculation of single-phase and two-phase flowing pressure gradients in a well annulus is generally based on an extension of empirical correlations developed for Newtonian fluids in circular pipes. Various techniques for extending pipe flow correlations to an annular geometry have been presented in the literature which involve the representation of the annular well geometry with an equivalent circular diameter and the representation of non-Newtonian fluid behavior with an apparent Newtonian viscosity. Unfortunately, little experimental data have been available which would allow a comparison of the relative accuracy of the various proposed techniques. In this study, experimental pressure gradient data have been taken in two 6000-ft wells. Frictional pressure losses for single-phase flow (mud only) in two annuli were compared to values predicted by the Bingham plastic and power law models. These calculations utilized the equivalent diameters defined by the Crittendon criteria, the hydraulic diameter, and the slot approximation. Also, total pressure difference for two-phase flow was measured for one annular geometry. This data was compared to that predicted by the Poettmann and Carpenter, Hagedorn and Brown, Orkiszewski, and Beggs and Brill correlations. Comparison of experimental data with the various prediction techniques was favorable, each having advantage in certain situations. For the data investigated, the Crittendon criteria using a Bingham plastic model gave the best results. The two-phase flow data was best predicted by the Hagedorn and Brown correlation utilizing an equivalent hydraulic diameter.

Thermal Modeling of a Reversing Valve in a Refrigeration System

2003 ◽  
Author(s):  
Shirish Raichintala ◽  
Manohar Kulkarni
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Heat Pump ◽  
Pressure Losses ◽  
Heat Leakage ◽  
Theoretical Predictions ◽  
Work Input ◽  
Compressor Work ◽  
Mass Leakage ◽  
The Mathematical Model

A mathematical model of a reversing valve was developed in order to evaluate the losses and for determining the effects of a reversing valve, on the performance of a heat pump. This mathematical model of the reversing valve was tested using the experimental data of Fang and Nutter (1999). The theoretical predictions made by this model agreed with that of the experimental data. Further, the mathematical model isolated the pressure losses due to friction; pipe-fittings, mass-leakage and heat transfer from the total losses. The evaluation of constituent losses assisted in detecting a faculty reversing valve, and also determining the effect of mass leakage and heat leakage on the compressor work input and COP of the heat pump.

Study on Three-Dimensional Turbulence Characteristics of Curved Channel Flow

2011 ◽  
Vol 94-96 ◽  
pp. 989-994
Author(s):  
Ri Sheng Wang ◽  
Kai Shi
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Channel Flow ◽  
Average Velocity ◽  
Three Dimensional ◽  
Flow Distribution ◽  
Curved Channel ◽  
Turbulence Characteristics ◽  
Time Average ◽  
Curved Channel Flow

The paper presents an experimental study on three-dimensional turbulence characteristics of curved channel flow by Doppler meter .Measured the time-average velocity and fluctuating intensity and so on. Analysised turbulence characteristics of curved channel flow by the experimental data,and also compared the flow distribution of vertical、horizontal fluctuating intensity,get the conclusion.

A Model for Flow Distribution in Manifolds

1971 ◽  
Vol 93 (1) ◽  
pp. 7-12 ◽  
Author(s):  
R. A. Bajura
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Analytical Model ◽  
Distribution Systems ◽  
Numerical Solutions ◽  
Flow Behavior ◽  
Flow Distribution ◽  
Analytical Investigation ◽  
Momentum Balance ◽  
Distribution Equation

An analytical investigation of the performance of flow distribution systems was conducted for both intake and exhaust manifolds. Primary emphasis was placed on configurations in which the lateral tubes formed sharp-edged junctions at right angles to the manifold axis. A mathematical model describing the flow behavior at a discreet branch point was formulated in terms of a momentum balance along the manifold. The model was extended to the case of continuous discharge or intake for a uniformly porous manifold. Numerical solutions of the governing flow distribution equation were obtained and compared with experimental data. Dimensionless parameters characterizing the performance of manifolds were formulated from the analytical model.

scholarly journals CFD Method for Predicting Annular Pressure Losses and Cuttings Concentration in Eccentric Horizontal Wells

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Titus N. Ofei ◽  
Sonny Irawan ◽  
William Pao
Keyword(s):  
Experimental Data ◽  
Oil And Gas ◽  
Current Model ◽  
Fluid Velocity ◽  
Pipe Diameter ◽  
Pressure Losses ◽  
Gas Drilling ◽  
Drilling Parameters ◽  
Drilling Operations ◽  
Oil And Gas Drilling

In oil and gas drilling operations, predictions of pressure losses and cuttings concentration in the annulus are very complex due to the combination of interacting drilling parameters. Past studies have proposed many empirical correlations to estimate pressure losses and cuttings concentration. However, these developed correlations are limited to their experimental data range and setup, and hence, they cannot be applicable to all cases. CFD methods have the advantages of handling complex multiphase flow problems, as well as, an unlimited number of physical and operational conditions. The present study employs the inhomogeneous (Eulerian-Eulerian) model to simulate a two-phase solid-fluid flow and predict pressure losses and cuttings concentration in eccentric horizontal annuli as a function of varying drilling parameters: fluid velocity, diameter ratio (ratio of inner pipe diameter to outer pipe diameter), inner pipe rotation speed, and fluid type. Experimental data for pressure losses and cuttings concentration from previous literature compared very well with simulation data, confirming the validity of the current model. The study shows how reliable CFD methods can replicate the actual, yet complex oil and gas drilling operations.

NUMERICAL STUDY OF THE EFFECT OF AREA OF MANIFOLD AND INLET/OUTLET FLOW ARRANGEMENT 0N FLOW DISTRIBUTION IN PARALLEL RECTANGULAR MICROCHANNEL COOLING SYSTEM

2017 ◽  
Vol 79 (7-3) ◽  
Author(s):  
Amirah M. Sahar ◽  
A. I. M. Shaiful
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Cooling System ◽  
Numerical Study ◽  
Flow Distribution ◽  
Fluid Temperature ◽  
Rectangular Microchannel ◽  
Temperature Distributions ◽  
Micro Channels ◽  
Parallel Microchannels

Parallel microchannels have been widely used in cooling of compact electronic equipment due to large contact area with liquid and availability of large mass of fluid to carry away heat. However, understanding of flow distribution for microchannel parallel system is still unclear and there still lack of studies give a clear pictures to understand the complex flow features which cause the flow maldistribution. Generally, the geometrical structure of the manifold and micro channels play an important role in flow distribution between micro channels, which might affects the heat and mass transfer efficiency, even the performance of micro exchangers. A practical design of exchanger basically involves the selection of an optimized solution, keeping an optimal balance between gain in heat transfer and pressure drop penalty. A parallel microchannels configurations consisting inlet and outlet rectangular manifold were simulated to study flow distribution among the channels were investigated numerically by using Ansys Fluent 14.5. The numerical results was validated using existing experimental data and showed a similar trend with values 1% higher than experimental data. The influence of inlet/outlet manifold area and inlet/outlet arrangement on flow distribution in channels were carried out in this study. Based on the predicted flow non-uniformity value, 𝜙, Z- type flow arrangement exhibits higher value of 𝜙, which is 8%, followed by U-type, 2.6% and the I-type, 2.49%. Thus, a better uniformity of velocity and temperature distributions can be achieved in I-shape flow arrangement. The behavior of the flow distributions inside channels is due to the vortices that occurred at manifold. Besides comparing the pressure drop for case 1(D1) and case 2(D2), it is worth to mention that, as the area of inlet and outlet manifold decrease by 50%, the pressure drop is increasing about 5%. However, the inlet/outlet area of manifold on velocity and fluid temperature distributions was insignificant.

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