scholarly journals Flow Visualization of Golf Ball in Subsonic Incompressible Flow Regime

2021 ◽  
Vol 1057 (1) ◽  
pp. 012046
Author(s):  
M Bhargavi ◽  
K Navaneetha ◽  
V Guru shanker
Keyword(s):  
Flow Visualization ◽  
Flow Regime ◽  
Incompressible Flow ◽  
Golf Ball

scholarly journals Experimental Analysis of Gas–Liquid–Solid Three-Phase Flows in Horizontal Pipelines

2020 ◽  
Vol 105 (4) ◽  
pp. 1035-1054
Author(s):  
Paolo Sassi ◽  
Youssef Stiriba ◽  
Julia Lobera ◽  
Virginia Palero ◽  
Jordi Pallarès
Keyword(s):  
Flow Visualization ◽  
Flow Regime ◽  
Solid Particles ◽  
High Complexity ◽  
Flow Conditions ◽  
Two Phase Flows ◽  
Two Phase ◽  
Three Phase ◽  
Inner Diameter ◽  
The Individual

AbstractThe dynamics of three-phase flows involves phenomena of high complexity whose characterization is of great interest for different sectors of the worldwide industry. In order to move forward in the fundamental knowledge of the behavior of three-phase flows, new experimental data has been obtained in a facility specially designed for flow visualization and for measuring key parameters. These are (1) the flow regime, (2) the superficial velocities or rates of the individual phases; and (3) the frictional pressure loss. Flow visualization and pressure measurements are performed for two and three-phase flows in horizontal 30 mm inner diameter and 4.5 m long transparent acrylic pipes. A total of 134 flow conditions are analyzed and presented, including plug and slug flows in air–water two-phase flows and air–water-polypropylene (pellets) three-phase flows. For two-phase flows the transition from plug to slug flow agrees with the flow regime maps available in the literature. However, for three phase flows, a progressive displacement towards higher gas superficial velocities is found as the solid concentration is increased. The performance of a modified Lockhart–Martinelli correlation is tested for predicting frictional pressure gradient of three-phase flows with solid particles less dense than the liquid.

Analysis and Modeling of the Vortex Amplifier

1969 ◽  
Vol 91 (4) ◽  
pp. 755-763 ◽  
Author(s):  
R. T. Bichara ◽  
P. A. Orner
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Computer Program ◽  
Flow Regime ◽  
Incompressible Flow ◽  
Digital Computer ◽  
Input Output ◽  
Critical Dimensions ◽  
Fluid Properties ◽  
Output Characteristics

A model has been derived to predict the steady-state input-output characteristics of vortex amplifiers operating in the incompressible flow regime. The model was correlated with experimental data to affect prediction of the influence of the operating fluid properties and the vortex valve critical dimensions on the valve characteristics. The model has been implemented in a digital computer program which includes procedures for the design of vortex valves with specified flow and pressure turndown ratios and the design of vortex amplifiers with proportional (single-valued) characteristics.

A Design Basis for Vortex-Type Fluid Amplifiers Operating in the Incompressible Flow Regime

1970 ◽  
Vol 92 (2) ◽  
pp. 369-376 ◽  
Author(s):  
D. N. Wormley ◽  
H. H. Richardson
Keyword(s):  
Flow Regime ◽  
Incompressible Flow ◽  
Experimental Studies ◽  
Maximum Flow ◽  
Vortex Chamber ◽  
Control Flow ◽  
Port Area ◽  
Performance Specifications ◽  
Fluid Properties ◽  
Control Port

A rational procedure is developed for the design of a class of vortex amplifiers which operate in the incompressible flow regime. The procedure is based upon analytical and experimental studies conducted to determine the effects of fluid properties and geometry on vortex amplifier behavior. These studies indicate that the nondimensional amplifier characteristic is essentially independent of the maximum flow Reynolds number, vortex chamber height, and supply port area if each of these parameters is within a specified broad range of values. The nondimensional characteristic was found to depend fundamentally upon the chamber exit to outer periphery radius ratio and the control port area to exit port area ratio. A systematic method is provided for progressing from a set of desired amplifier performance specifications, which include maximum control and supply port pressure and flow requirements, to a specification of each critical amplifier dimension. Three-point predictions of the transfer characteristics are obtained and the characteristics are checked to determine if multiple values of total flow exist at the cutoff value of control flow. The measured performance of a planar vortex amplifier designed with the aid of the procedure was found to agree closely with the desired performance specifications.

Condensation Flow Mechanisms in Microchannels: Basis for Pressure Drop and Heat Transfer Models

2003 ◽  
Author(s):  
Srinivas Garimella
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Flow Visualization ◽  
Flow Regime ◽  
Annular Flow ◽  
Flow Regimes ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Flow Mechanisms ◽  
Transfer Models

This paper presents an overview of the use of flow visualization in micro- and mini-channel geometries for the development of pressure drop and heat transfer models during condensation of refrigerants. Condensation flow mechanisms for round, square and rectangular tubes with hydraulic diameters in the range 1–5 mm for 0 < x < 1 and 150 kg/m2-s and 750 kg/m2-s were recorded using unique experimental techniques that permit flow visualization during the condensation process. The effect of channel shape and miniaturization on the flow regime transitions was documented. The flow mechanisms were categorized into four different flow regimes: intermittent flow, wavy flow, annular flow, and dispersed flow. These flow regimes were further subdivided into several flow patterns within each regime. It was observed that the intermittent and annular flow regimes become larger as the tube hydraulic diameter is decreased, at the expense of the wavy flow regime. These maps and transition lines can be used to predict the flow regime or pattern that will be established for a given mass flux, quality and tube geometry. These observed flow mechanisms, together with pressure drop measurements, are being used to develop experimentally validated models for pressure drop during condensation in each of these flow regimes for a variety of circular and noncircular channels with 0.4 < Dh < 5 mm. These flow regime-based models yield substantially better pressure drop predictions than the traditionally used correlations that are primarily based on air-water flows for large diameter tubes. Condensation heat transfer coefficients were also measured using a unique thermal amplification technique that simultaneously allows for accurate measurement of the low heat transfer rates over small increments of refrigerant quality and high heat transfer coefficients characteristic of microchannels. Models for these measured heat transfer coefficients are being developed using the documented flow mechanisms and the corresponding pressure drop models as the basis.

Heat Transfer Between an Impinging Jet and a Rotating Disk

1977 ◽  
Vol 99 (4) ◽  
pp. 663-667 ◽  
Author(s):  
D. E. Metzger ◽  
L. D. Grochowsky
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Flow Visualization ◽  
Flow Regime ◽  
Cross Flow ◽  
Impinging Jet ◽  
Rotating Disk ◽  
Transfer Rates ◽  
Flow Regime Transition ◽  
Flow Interaction

An experimental study of the flow interaction and heat transfer between a single impinging jet and a rotating disk is presented. Tests were conducted over a range of jet flowrates, impingement radii, and disk rotational speeds with various combinations of three jet and three disk sizes. Flow visualization using smoke addition to the jet flow reveals the presence of a flow regime transition which is correlated in terms of the rotationally induced disk pumping flow acting as a cross-flow influence on the jet. Higher rotational speeds, larger impingement radii, and smaller jet flowrates favor a rotationally dominated flow interaction whereas the opposite trends favor an impingement dominated interaction. Heat transfer rates are essentially independent of jet flowrate in the rotationally dominated regime, but increase, strongly with increasing flowrate in the impingement dominated regime.

Application of Endwall Contouring to Transonic Turbine Cascades: Experimental Measurements at Design Conditions

2011 ◽  
Author(s):  
F. Taremi ◽  
S. A. Sjolander ◽  
T. J. Praisner
Keyword(s):  
Kinetic Energy ◽  
Flow Visualization ◽  
Flow Regime ◽  
Total Pressure ◽  
Surface Flow ◽  
Secondary Flows ◽  
Experimental Results ◽  
Pressure Losses ◽  
Turbine Cascades ◽  
Endwall Contouring

An experimental investigation of the endwall flows in two transonic linear turbine cascades was presented at the 2010 ASME Turbo Expo (GT2010–22760). Endwall contouring was subsequently implemented in these cascades to control the secondary flows, and reduce the total pressure losses. The current paper presents experimental results from these cascades to assess the effectiveness of endwall contouring in the transonic flow regime. The experimental results include blade loadings, total pressure losses, streamwise vorticity and secondary kinetic energy distributions. In addition, surface flow visualization results are presented in order to interpret the endwall limiting streamlines within the blade passages. The flat-endwall and contoured-endwall cascades produce very similar midspan loading distributions and profile losses, but exhibit different secondary flows. The endwall surface flow visualization results indicate weaker interaction between the secondary flows and the blade suction surface boundary layers in the contoured cascades. Overall, the implementation of endwall contouring results in smaller and less intense vortical structures, and the reduction of the associated secondary kinetic energy (SKE) and exit flow angle variations. However, the mass-averaged losses at the main measurement plane, located 40% axial chord lengths downstream of the cascade (1.4CX), do not corroborate the numerically predicted improvements for the contoured cascades. This is in part attributed to slower mixing rates of the secondary flows in the compressible flow regime. The mass-averaged results at 2.0CX, on the other hand, show smaller losses for the contoured cascades associated with smaller SKE dissipation downstream of the cascades. Accordingly, the mixed-out row losses also show improvements for the contoured cascades.

Two-Phase Flow Regimes in Exchangers and Piping: Part 1

2015 ◽  
Author(s):  
Siddharth Talapatra ◽  
Kevin Farrell
Keyword(s):  
Flow Visualization ◽  
Flow Regime ◽  
Void Fraction ◽  
Heat Exchangers ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase Flows ◽  
Two Phase ◽  
Gas Phases ◽  
Shell And Tube

The ability to predict the liquid-gas two-phase flow regime and void fraction in exchangers and piping is a critical engineering requirement in the process industry. The distribution of the liquid and gas phases depend on many factors including flow conditions, physical properties of the two fluids, and geometry of the flow conduit. The problem of correctly predicting the two-phase distribution is of enormous complexity, and generalized correlations that adequately describe the flow regime and/or the void fraction have not been yet been developed even for the simplest of geometries. While Computational Fluid Dynamics codes that model two-phase flows exist, they are limited in their applicability and usually require a priori knowledge of the flow regime. In this part of a two paper series, we discuss the state-of-the-art in two-phase flow regime studies inside shell-and-tube heat exchangers, while in the second part, we will discuss two-phase flows inside piping. We have performed air-water tests inside a glass shell-and-tube exchanger at HTRI, and by systematically varying various geometrical parameters, compiled the largest flow visualization database inside such exchangers. We have evaluated the best available flow regime maps available in the open literature, and shown how our results help enhance understanding of liquid-gas distribution inside heat exchangers. We have shown how, for a given flow rate, increasing the baffle spacing and reducing baffle-cut enhances two-phase separation. While these results are expected, they have never been quantified before. However, the use of flow visualization limits the liquid and gas phases to water and air mixtures, which limits the range of applicability. Shellside studies using various industrially relevant fluids such as hydrocarbon mixtures, steam water are planned, where non-visual flow regime detection techniques need to be applied.

Flow Regime Definition for Flow Between Corotating Disks

1974 ◽  
Vol 96 (1) ◽  
pp. 29-34 ◽  
Author(s):  
L. L. Pater ◽  
E. Crowther ◽  
W. Rice
Keyword(s):  
Experimental Data ◽  
Laminar Flow ◽  
Turbulent Flow ◽  
Flow Visualization ◽  
Pressure Distribution ◽  
Flow Regime ◽  
Radial Pressure ◽  
Distribution Data ◽  
Wide Range ◽  
Incompressible Newtonian Fluid

Experimental data and results are presented for the flow of an incompressible Newtonian fluid, with full admission, between closely spaced corotating disks, and for both radially inward and radially outward throughflows. The data consist of the measured radial pressure distribution together with flow visualization by means of injected dye, over a very wide range of parameters descriptive of the flows. From the data, the combinations of the parameters corresponding with laminar and with turbulent flow are determined; that is, the data are sufficient to define the flow regimes. Furthermore, for laminar flow, both the pressure distribution data and the flow visualization data confirm the adequacy of earlier analytical results for use in the design of practical devices incorporating these flows, such as multiple disk pumps and turbines.

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